McQuay AZR User Manual

Download

Catalog UV1620

AAF-HermanNelson Classroom Unit Ventilators

Models AZQ, AZR, AZU Self-Contained Floor Units with R-410A Refrigerant

Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Nomenclature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

AAF-HermanNelson Classroom Unit Ventilators . . . . . . . . . . . 4

The Model AZ Floor Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Features & Benefits. . . . . . . . . . . . . . . . . . . . . . . . . 6

GentleFlo Delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

The Right Amount of Fresh Air and Cooling. . . . . . . . . . . . . . . 7

Precise Temperature and Dehumidification Control. . . . . . . . . 7

Low Installation Costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Easy To Maintain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Built To Last . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

MicroTech II Controls . . . . . . . . . . . . . . . . . . . . . . 13

MicroTech II Controls For Superior Performance, Easy Integra-

tion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Control Modes and Functions . . . . . . . . . . . . . . . . . . . . . . . . 14

System Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Wall Louvers & Grilles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

VentiMatic™ Shutter Room Exhaust Ventilation . . . . . . . . . . 25

Storage Cabinets, Sink & Bubbler . . . . . . . . . . . . . . . . . . . . . 26

End Panels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Application Considerations . . . . . . . . . . . . . . . . . 27

Why Classrooms Overheat . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Meeting IBC Seismic Requirements. . . . . . . . . . . . . . . . . . . . 31

Face & Bypass Temperature Control. . . . . . . . . . . . . . . . . . . 32

Modulating Valve Temperature Control . . . . . . . . . . . . . . . . . 34

Wall Sleeve Arrangements. . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Unit Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Quick Selection Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Selection Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Hot Water Heating Selection. . . . . . . . . . . . . . . . . . . . . . . . . 45

Steam Heating Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Engineering Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Valve Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Face and Bypass End-Of-Cycle Valve Sizing & Piping . . . . 50

Modulating Valve Sizing & Piping. . . . . . . . . . . . . . . . . . . . . 51

Steam Valve Sizing & Piping . . . . . . . . . . . . . . . . . . . . . . . . 52

Details & Dimensions . . . . . . . . . . . . . . . . . . . . . . 54

Coil Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Model AZ Self Contained Unit Dimensions, 024. . . . . . . . . . 57

Model AZ Self Contained Unit Dimensions, 036. . . . . . . . . . 58

Model AZ Self Contained Unit Dimensions, 044, 054. . . . . . 59

End Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Valve Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Wall Intake Louvers & Grilles . . . . . . . . . . . . . . . . . . . . . . . . 62

VentiMatic Shutter Assembly . . . . . . . . . . . . . . . . . . . . . . . . 63

Sink & Bubbler Cabinet. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Filler Sections & Utility Compartment . . . . . . . . . . . . . . . . . . 65

Shelf Storage Cabinets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Typical MicroTech II Wiring Diagrams . . . . . . . . . . . . . . . . . 68

Guide Specifications . . . . . . . . . . . . . . . . . . . . . . . 71

AAF-HermanNelson Unit Ventilator Model AZ Guide Specifica-

tions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

McQuay is a registered trademark and MicroTech II, Digital Ready, GentleFlo, ServiceTools,

Microsoft is a registered trademark and Windows is a trademark of Microsoft Corporation.

and Protocol Selectability are trademarks of McQuay International.

Introduction

Nomenclature

UC0246AZU G 65 B1Z

Product Category U = Unit Ventilator

Product Identifier

ZQ = SC - a/c Face & Bypass

Heating, Ultra Quiet

ZU = SC - a/c Valve Heating,

Ultra Quiet

ZR = SC - a/c Valve Reheat

Design Series 6 = F-Series

Nominal Capacity 024 = 24000 BTUH 036 = 36000 BTUH 044 = 44000 BTUH 054 = 54000 BTUH

Voltage C = 208V, 60Hz, 1Ø D = 208V, 60Hz, 3Ø G = 230V, 60Hz, 1Ø H = 230V, 60Hz, 3Ø K = 460V, 60Hz, 3Ø

Cooling Coil Options G = Direct Expansion H = Direct Expansion with Refrigerant Relief Valve

Heating Options 00 = None 12 = Low Electric Heat, 3-Element 13 = High Electric Heat, 6-Element 65 = 1 Row Hot Water 66 = 2 Row Hot Water 68 = Steam, Low Capacity 69 = Steam, High Capacity

Hand Orientation Z = Not Applicable

Control Options B1 = Basic Stand-Alone w/o TC B2 = Basic Stand-Alone Master w/o TC B3 = Basic Stand-Alone Slave w/o TC B4 = Basic BACnet MS/TP w/o TC B5 = Basic LonMark SCC w/o TC B6 = Basic Metasys N2 Open w/o TC B7 = Basic Stand-Alone w/ TC B8 = Basic Stand-Alone Master w/ TC B9 = Basic Stand-Alone w/o TC w/CO2 BA = Basic Stand-Alone Master w/o TC w/CO2 BB = Basic Stand-Alone Slave w/o TC w/CO2 BC = Basic BACnet MS/TP w/o TC w/CO2 BD = Basic LonMark SCC w/o TC w/CO2 BE = Basic Metasys N2 Open w/o TC w/CO2 BF = Basic Stand-Alone w/ TC w/CO2 BG = Basic Stand-Alone Master w/ TC w/CO2

AL 22 G BC1

Product Style 1 = Product Style 1

SKU Type B = Std. Delivery C = Ext. Delivery

Color I = Antique Ivory W = Off White B = Putty Beige G = Soft Gray

Power Connection G = Box with Switch

Return Air/Outdoor Air 22 = Return Air Front,

Outdoor Air Rear

Discharge AL = 16 5/8" Top Bar

Control Options (continued) E1 = Expanded Stand-Alone w/o TC E2 = Expanded Stand-Alone Master w/o TC E3 = Expanded Stand-Alone Slave w/o TC E4 = Expanded BACnet MS/TP w/o TC E5 = Expanded LonMark SCC w/o TC E6 = Expanded Metasys N2 Open w/o TC E7 = Expanded Stand-Alone w/ TC E8 = Expanded Stand-Alone Master w/ TC E9 = Expanded Stand-Alone w/o TC w/CO2 EA = Expanded Stand-Alone Master w/o TC w/CO2 EB = Expanded Stand-Alone Slave w/o TC w/CO2 EC = Expanded BACnet MS/TP w/o TC w/CO2 ED = Expanded LonMark SCC w/o TC w/CO2 EE = Expanded Metasys N2 Open w/o TC w/CO2 EF = Expanded Stand-Alone w/ TC w/CO2 EG = Expanded Stand-Alone Master w/ TC w/CO2 L1 = Leading Stand-Alone w/o TC L2 = Leading Stand-Alone Master w/o TC L3 = Leading Stand-Alone Slave w/o TC L4 = Leading BACnet MS/TP w/o TC L5 = Leading LonMark SCC w/o TC L6 = Leading Metasys N2 Open w/o TC L7 = Leading Stand-Alone w/ TC L8 = Leading Stand-Alone Master w/ TC L9 = Leading Stand-Alone w/o TC w/CO2 LA = Leading Stand-Alone Master w/o TC w/CO2 LB = Leading Stand-Alone Slave w/o TC w/CO2 LC = Leading BACnet MS/TP w/o TC w/CO2 LD = Leading LonMark SCC w/o TC w/CO2 LE = Leading Metasys N2 Open w/o TC w/CO2 LF = Leading Stand-Alone w/ TC w/CO2 LG = Leading Stand-Alone Master w/ TC w/CO2 44 = Electromech w/2-Pos Damper for Remote T'Sta 45 = Electromech w/2-Pos Damper w/Unit Mtd. ACO 46 = Electromech w/2-Pos Damper w/Unit Mtd. MCO

Grille Unit

AAF-HermanNelson Model AZ Unit Ventilators 3

Introduction

AAF-HermanNelson Classroom Unit Ventilators

For more than 89 years, schools have relied on AAF-HermanNelson unit ventilators to keep classrooms comfortable. Students learn more readily in a quiet, wellventilated environment. That’s why Herman Nelson invented the unit ventilator and why we remain committed to meeting the changing requirements of schools with the highest quality products available.

We realize that keeping expenditures down is a high

iority for school administrators and school boards.

p AAF-HermanNelson unit ventilators are inexpensive to install and operate, and they are designed and built to provide decades of trouble-free service.

Built To Last

Our proven institutional design can withstand the rigors of the classroom environment. It features an extra-sturdy chassis and double-wall damper on the inside; scuffresistant finishes and tamper prevention features on the outside. In fact, many units installed over 30 years ago continue to provide quiet, reliable classroom comfort.

Heavy Duty Frame Construction

AAF-HermanNelson’s exclusive, unitized welded frame is far superior to the fastener-type construction used by other manufacturers. Loosened fasteners can cause vibration, rattles and sagging panels.

Other design features that promote trouble-free

per

ation and long life include:

• A corrosion-resistant, galvanized-steel frame.

• Extra-strength, steel-bar disc

• Heavy-gauge-metal cabinet access panels and doors.

• An extra-str

ength pipe tunnel that stiffens the structure

while adding aerodynamic air flow within the unit.

• Hidden reinforcement that provides additional built-in ort for the top section as well as better support for

supp the fan deck assembly.

harge grille.

igid exterior that is strong enough to support

• A r main

tenance personnel without fear of damaging the

unit.

Rugged Exterior Finish

The superior finish of the unit ventilator cabinet fosters long-lasting beauty as well as resistance to abuse and corrosion. We apply the very highest standards at every step of the finishing process to provide lasting quality:

• Exter

ior cabinet panels are fabricated from high-

qua

lity, furniture grade steel with no sharp edges.

• A specially formulated, environmentally friendly,

ermosetting urethane powder is applied

th electrostatically to the exterior panels. This film is oven-cured to provide correct chemical cross-linking and to obtain maximum scuff- and mar-resistance.

he top of the unit is finished with a textured, non-glare

• T and

scuff-resistant, charcoal bronze electrost atic pa int. End and front panels are available in a pleasing array of architectural colors.

he Oxford brown steel kickplate is coated and baked

• T with a

thermosetting urethane powder paint to blend with floor moldings and provide years of trouble-free service.

h unit is painstakingly inspected before

• Eac then encapsulated in a clear plastic bag, surrounded by an extra-heavy-duty cardboard box and secured to a skid to help provide damage-free shipment.

MicroTech II Control For Superior Performance, Easy Integration

AAF-HermanNelson unit ventilators can be equipped with MicroTech II™ unit controllers for superior performance. Factory integrated and tested controller, sensor, actuator and unit options promote quick, reliable start-up and minimize costly field commissioning. Our Protocol Selectability feature provides easy, low-cost integration into most building automation systems. Select BACnet communications to communicate control and monitoring information to your BAS, without the need for costly gateways. Unit controllers are L the optional L

, LonTalk® or Metasys® N2 Open

ONWORKS

communication module.

ONMARK

certified with

boxing,

4 McQuay Catalog 1620

Introduction

The Model AZ Floor Unit

Our Model AZ is a vertical, floor-standing unit that utilizes refrigerant for cooling, and hot water, steam or electric heat for heating. The Model AZ also can be supplied as a cooling/ventilating unit only.

The Model AZ is just right for new construction and for

etrofit applications. Older buildings with baseboard

r radiant heat or other hydronic heating systems can be easily adapted to work efficiently with Model AZ units. The major features of this model are shown below and described in more detail on the following pages.

1 Welded One-Piece Chassis offers

superior strength, durability, and vibration reduction.

2 Unique Draw-Thru Design provides

uniform air distribution across the coil for even discharge air temperatures.

3 Quiet, Aerodynamic Fans utilize

GentleFlo technology for exceptionally quiet unit operation.

4 Modular Fan Section improves

balance, alignment and simplifies maintenance.

Fan Motor Located Out Of Air Stream

and away from heating coil

reduces heat exposure to prolong life.

6 Outside Air/Return Air Damper &

Linkage Provides superior mixture of

outdoor air and room air for precise temperature control.

7 MicroTech II Controls provide

superior comfort control and easy integration into the building automation system of your choice.

8 Advanced Heat Transfer Coil

design provides extra capacity.

9 Sturdy Cabinet Construction

includes hidden reinforcement, a non-glare textured surface, and a tough, scuff- and mar-resistant finish to make the top sturdy enough to support maintenance personnel.

10 Sectionalized Front Access Panels

provide easy access to unit interior. Panels are easily removed by a single person. Front side panels can be removed while unit is running.

11 Two Hinged To p Access Doors

provide easy access to the motor, electrical, and refrigeration components..

12 Sampling Chamber for unit-

mounted sensor provides accurate sensing of room temperature.

13 Optional Adjustable Caster (Left

and Right Ends).

14 Insulated Double-Wall Outdoor Air

Damper seals tightly without

twisting.

15 Full-leng t h Air Filt er is efficient and

easy to replace. All air delivered to classroom is filtered.

16 Corrosion Proof Sloped Drain Pan. 17 Tamper Resistant Fasteners on

Access Panels

AAF-HermanNelson Model AZ Unit Ventilators 5

Features & Benefits

GentleFlo Delivery

AAF-HermanNelson unit ventilators are engineered and manufactured to deliver quiet, continuous comfort. We developed our GentleFlo™ air moving syst em to minimize operating sound levels—even as demands for more fresh air require units to operate longer and work harder. GentleFlo featur es include:

wheels are large, wide and rotate at a low speed

• Fan to red

uce fan sound levels. They are impact-resistant and carefully balanced to provide consistent performance.

fset, aerodynamic fan wheel blades move air

• Of ef

ficiently (Figure 1).

• Precision tolerances help reduce flow and pr es su re turbulence, resulting

in lower sound levels.

• Fan housings incorporate the latest logarithmic-

ansion technology for smoother, quieter air flow

exp (Figure 2).

Figure 1. GentleFlo Fan Technology

Expanded discharge air opening

• A large, expanded discharge opening minimizes air resistance, further lowering sound levels.

• Modular fan construction contributes to equal outlet

locities and promotes quiet operation.

• Fan shafts are of ground and polish ed steel to

ize deflections and provide consistent, long-term

minim operation.

• Fan assemblies are balanced before unit assembly,

en tested after assembly (and rebalanced if

th necessary) to provide stable, quiet operation.

Figure 2. GentleFlo Reduces Turbulence

Minimal

Offset aerodynamic blades

Logarithmic expansion housing

Precision Tolerances

6 McQuay Catalog 1620

GentleFlo fan blade design

turbulence

Typical fan blade design

High turbulence

Features & Benefits

The Right Amount of Fresh Air and Cooling

AAF-HermanNelson unit ventilators deliver required amounts of fresh air to meet ventilation requirement s and added cooling capacity to maintain consistent comfort for students and teachers. Our Economizer Operation, Demand Control Ventilation (DCV) and Part Load, Variable Air options allow you to mat ch cla ssr oo m comfort requirements even more closely, and reduce operating costs.

at your school is

This means that you can be confiden meeting ventilation standards for Indoor Air Quality and that your students are receiving adequate air to be attentive to instruction. At the same time, you are saving money in early morning hours, between classes or after hours when classrooms are heated and cooled but not always fully occupied.

Economizer Operation

It is well recognized that cooling, not heating, is the main thermal challenge in school classrooms. The typical classroom is cooled by outdoor air over half the time, even in cold climates. It is therefore essential that unit ventilators efficiently deliver outdoor air when classroom conditions call for “free” or economizer cooling.

With AAF-HermanNelson unit ventilators, you can have

tdoor air whenever it is needed. Economize r operatio n

o is facilitated by the outdoor air damper, which automatically adjusts the above-minimum outside air position to provide free cooling when the outdoor air temperature is appropriate (Figure 3). On unit s equippe d with MicroTech II controls, three levels of economizer

rol are available (see See “Economizer Modes” on

con page 14).

Figure 3. Full Economizer Mode

100% Outdoor Air Into Classroom

Condenser Section

Face & Bypass Damper

Room Air Damper

t th

Filter

Outdoor Air Damper

Outdoor Air

Part-Load Variable Air Control

Part Load Variable Air control can be used in conjunction with face and bypass damper temperature control to automatically adjust the unit ventilator fan speed based upon the room load and the room temperat ure. This MicroTech II control option provides higher latent cooling capabilities and quieter operation during non-peak load periods by basing indoor fan speed upon room load. Lower fan speeds in conjunction with our GentleFlo fan technology contributes to a very quiet classroom environment.

Room-temperature PI control loops determine the speed

e fan, wh

of th also provides a built-in delay to prevent overshooting for better comfort control. The outdoor air damper’s minimum-air position is adjusted with the fan speed to bring in a constant amount of fresh air.

ich varies according to the room load. It

Precise Temperature and Dehumidification Control

AAF-HermanNelson unit ventilators provide precise temperature and dehumidification control to keep students and teachers comfortable while making maximum use of “free” outdoor-air cooling to reduce operating costs. They utilize a draw-thru fan design that contributes to even heat transfer and provides uniform discharge air temperatures into the classroom. MicroTech II active dehumidification control strategies and 2-stage compressor operation, provide precise control of temperature and humidity levels under both part-load and full-load conditions.

Draw-Thru Design For Even Discharge Temperatures

The AAF-HermanNelson Draw-Thru design sets our unit ventilators apart from most competitive models. With this system, fans draw air through the entire heat transfer element (Figure 4) rather than blowing it through highly concentrated areas of the coil element. The result is

re uniform discharge air temperatures into the

m classroom and more efficient unit ventilator operation.

AAF-HermanNelson Model AZ Unit Ventilators 7

Features & Benefits

Figure 4. Draw-Thru Design Provides Even Discharge Air

Uniform Discharge Air (Shaded)

Motor

Fans

Condenser

Face & Bypass Design For Better Temperature Control

When coupled with our draw-thru design, face and bypass damper air control offers optimal temperature control in heating. That’s because indoor and out d oo r air streams can be separated until it is optimal to mix them.

Figure 5. Draw-Thru Vs. Blow-Thru Design

Coil

Filter

RA/OA Divider

Room Air

Outdoor Air

Blow-Thru Design

Face & Bypass Damper

Room Air Damper

Room Air

AAF-HermanNelson Draw-Thru Design

Coil

Outdoor Air Damper

Outdoor Air

Active Dehumidification (Reheat)

In high-humidity applications where valve-controlled, reheat units are used, the Active Dehumidification Control (ADC) sequence should be considered. With the Leading Edge Microtech II controls, an inside humiditst at compares indoor humidity (enthalpy) with outdoor humidity to determine the economizer position.

During excessive humidity conditions

, a humidity

sensor directs the unit to continue cooling p ast the room setpoint to remove moisture. Hydronic heat or electric heat is then used to reheat the discharge air to maintain acceptable room temperatures.

Increased Coil Freeze Protection

AAF-HermanNelson units equipped with face and bypass damper control, provide extra protection from coil freeze-up, because there is a constant flow of hot water

through the coil, and water that is flowing typically does not freeze. Additionally, all AAF-HermanNelson units feature a double-walled, insulated outdoor air damper with airtight mohair seals to prevent unwanted coil air from entering the unit.

Furthermore, a low-temperature freezestat is factory inst

alled on

all units with hydronic coils. Its serpentine capillary tube senses temperatures across the leaving air side of the coil, allowing the unit controller to react quickly to low-temperature conditions.

Figure 6. Freezestat

Freezestat

Capillary Tube

Low Installation Costs

Perfect For Both New & Retrofit Applications

New construction installations are easily accomplished with AAF-HermanNelson unit ventilators because they avoid the added cost and space required for expensive duct work. Further savings can be realized because piping installations use less space than duct systems. This is important in existing buildings and also in new construction where floor-to-floor heights can be reduced, saving on overall building costs.

Retrofit installations are economical because new units

pically

ty Using AAF-HermanNelson unit ventilators, central equipment, such as chillers, can be sized smaller using building diversity. This results in a low capital-cost system.

Built In Flexibility

AAF-HermanNelson unit ventilators include features that make them easy to set up and reconfigure as needed to meet special requirements. These features include:

• Built-In Wire Race A built-in meta

fit the same space occupied by existing ones.

l wire race runs from one end of the unit to the other to provide extra protection for wires and protect them from unit air.

8 McQuay Catalog 1620

Features & Benefits

Figure 7.

Condenser casters ease

installation. Optional indoor

casters can be adjusted.

Condenser Casters and Optional Unit Casters

Controls Flexibility

Multiple control options—including MicroTech II controls with our Protocol Selectability feature—provide easy , low cost integration of AAF-HermanNelson unit ventilators into the building automation system of your choice (See “MicroTech II Controls” on page 13) . You can also operate these units individually or in a master-servant

rol configuration.

con With MicroTech II controls, you can select BACnet,

alk or Metasys N2 communications to communicate

LonT control and monitoring information to your BAS, without

need for costly gateways. Unit controllers are

the

ONMARK certified with the optional LONWORKS

L communication module.

Then consider how AAF-HermanNelson unit ventilators, locate

d in each classroom, take advantage of these

realities to lower operating costs:

• They provide individual classroom control and comfort.

• They can be cycled on

when the room is occupied and

cycled off when it is not.

• They bring in fresh air from directly outside the ssroom for high indoor air quality.

cla

• During most of the school year, they use outdoor air to

ep classrooms comfortable without the expense of

ke mechanical cooling.

MicroTech II Control Options Further Reduce Operating Costs

Many of the MicroTech III control options available with AAF-HermanNelson unit ventilators can further reduce operating costs. For example:

• Economizer Operation Econ

automatically adjusts the above-minimum outside air position to provide free cooling when the outdoor air temperature is appropriate.

• Demand Control Ventilation By usin

monitor the actual occupancy pattern in a room, the system can allow code-specific levels of outdoor air to be delivered when needed without costly overventilation during periods of low or intermittent occupancy (Figure 8).

omizer operation

g CO

levels to

Low Operating Costs

Schools consume more than 10% of the total energy expended in the United States for comfort heating and cooling of buildings. As energy costs increase, educators are placed in a difficult position: caught between rising costs, lower budgets and the requirements to raise educational standards.

e system exists for

Fortunately, the technology an schools to take control of their energy expenditures wh ile providing a comfortable environment for learning. And that system is the AAF-HermanNelson unit ventilator.

Consider these realities of school environments:

• Most

heating energy in schools is expended to heat

occupied spaces. Because lights, computers and

students give off considerable heat, occupied spaces require little supplemental heat.

• The

removal

of heat is usually required in occupied classrooms, even when outside temperatures are moderately cold (i.e., 35-40°F).

d th

Figure 8. Energy Savings with Demand Control Ventilation

100%

Energy Savings

with DCV

Unoccupied

20%

DCV's fresh air for indoor air quality

6:00 8:00 10:00 12:00 2:00 4:00 6:00 8:00 10:00

School Hours

Cleaning

After Hours

Unoccupied

• Occupancy Mode Operation Units can be

programmed to operate only sparingly during unoccupied periods and at night to conserve energy.

Two Stage Compressor

Air conditioning units are usually sized for worse case conditions. During high load requirement the unit will operate in high fan speed and high compressor capacity. Most of the time there is not a full load on the compressor. Operation in lower load will be at medium or

AAF-HermanNelson Model AZ Unit Ventilators 9

Features & Benefits

low fan speeds which will be at the lower displacement compressor stage. The two stage compressor will remain at low speed until more cooling is required. With the twostage compressor, these units will run on lower fan speeds most of the time improving comfort through better humidity control and quieter operation, while minimizing issues with over-sizing.

ors operate at

Other units utilizing single stage compres full compressor capacity all of the time regardless of fan speed.

Easy To Maintain

Fan Deck

The fan deck’s rotating element has one large, selfaligning, oilable end bearing for smoother operation.

Figure 9. Long-Life Bearings

Long Life Bearing

Even “permanently” lubricated motors are supplied with recommended lubrication charts calling for lubrication every seven years. Maintenance instructions of the motor manufacturer should be followed clo sely.

Heavy-Duty Discharge Grille

The discharge grille on the top of the unit is made from extra-strength steel bar stock, promoting long life (Figure 10). It can be removed to facilitate cleaning fans and fan housings.

Figure 10. Heavy-Duty Steel Discharge Grille

Internal Fan Deck Components

Unlike with many competitive models, the motor in AAF-HermanNelson unit ventilators is separate from the fan assembly and is located out of the airstream at the end of the fan shaft—away from the hot coil—for easier maintenance and removal. Locating the motor away from the coil (Figure 11) has the added benefit of extending motor life. Our direct-coupled motor and self-aligning

r mount facilitate motor change-out. The motor

mo comes with a molex plug that fits all sizes and further simplifies removal.

Figure 11. Fan Deck

Aerodynamic Fans

Modular

Fan Deck

Heavy-Duty

Discharge Grille

Motor Located

Out of Airstream

Filter

10 McQuay Catalog 1620

Features & Benefits

Tamper-Resistant Fasteners

Front panels and top access doors are held in place by tamper-resistant, positive-positioning fasteners. They are quickly removed or opened with the proper tool, but deter unauthorized access to the unit’s interior (Figure 12).

Sectionalized Access Panels And Doors

All units have three separate front panels and hinged top access doors, sized for convenient handling by a single person (Figure 12). The result is easy , t argeted access to the component that needs servicing:

wo end panels provide easy access to piping,

• T te

mperature control components and the fan switch. Unlike units with full-length front panels, these can be removed without disturbing the normal operation of the unit.

ged top access doors provide easy access into the

• Hin end c

ompartments to facilitate convenient servicing of

the motor, electrical, and refrigeration components.

• Center front panel provides easy access to the filter

d fan shaft bearing (size 048 only).

Filter

Three filter types are offered:

• Units come standard with a single-use filter which is

signed to be used once and discarded.

• Optional, permanent metal filters are available and can

removed for cleaning and reused numerous times.

• Renewable media filters, which consist of a heavy-

uty, painted-metal structural frame and renewable

d media.

Figure 12. Easy Access With Tamper-Resistant Fasteners

Tamper Resistant

Fasteners

Tamper Resistant

Fasteners

Discharge

Grille

Tamper Resistant

Fasteners

Tamper Resistant

Fasteners

Removeable

Filter

AAF-HermanNelson Model AZ Unit Ventilators 11

Features & Benefits

Built To Last

Durable, Energy Efficient Fan Motors

AAF-HermanNelson unit ventilators are equipped with 1 15/60/1 NEMA motors that feature low operating curr ent and wattage (Figure 13).

Figure 13.

Additional features of these motors include:

• Split-capacitor (PSC) design with au thermal-overload protection.

• No brushes, contacts or centrifugal starting switches— the mo

• A built-in, decoupled isolation system to reduce tran

• A multi-tap, auto-transformer (Fi multiple fan motor speed control through the speed switch. The which allows stocking of one motor (school districtwide) for various voltage applications.

Figure 14. Multi-Tap Auto-Transformer

Energy-Efficient Fan Motor

Energy Efficient NEMA Motor

Decoupled Isolation System

tomatic reset and

st common causes of motor failure.

smission of vibrations for quieter operation.

gure 14) provides

motor is independent of supply voltage,

Nylon damper bearings foster quiet, maintenance-free operation.

Additional features include:

have

• Face and bypass dampers

a twist-free reinforced aluminum construction for durability. Aluminum is used because it is lightweight and noncorrosive, resulting in low torque and easy movement.

• Outdoor air dampers ar

made of galvanized steel to inhibit corrosion, with double-wall welded construction for rigidity and encapsulated insulation (Figure 15). Additional insulation is provided on the exterior of the

oor air damper blade and on the outdoor air entry

out portion of the unit.

Figure 15.

Wool Mohair End Seal

Outdoor Damper Seals Out Cold Weather

Turned Metal Damper Blade

Turned Metal Damper Stop

Full-Length Wool Mohair Damper

Additional Insulation

Wool Mohair End Seal

• Room air dampers are free-floating and designed to prevent intermittent gusts of cold air from blowing directly into the classroom on windy days (Figure 16). They are constructed of aluminum with built-in rigidity.

metal forming technique that is employed resists

The twisting and incorporates a full-length counter weight for easy rotation. The simple principle of an area exposed to a force is used to automatically close the damper, rather than open it, when gusts of cold air occur.

Figure 16.

Room Air Damper Auto-Closed By Wind Gusts

Wind Gust

Durable Damper Design

All dampers in AAF-HermanNelson Unit Ventilators use the turned-metal principle on their long closing edges (Figure 15). Positive sealing is provided by embedding

the edge into wool mohair (no met There are no plastic gaskets to become brittle with time, sag with heat or age, or require a difficult slot fit to seal.

12 McQuay Catalog 1620

l to metal contact).

MicroTech II Controls

MicroTech II Controls For Superior Performance, Easy Integration

AAF-HermanNelson unit ventilators equipped with MicroTech II unit controllers can

ovide superior performance

pr and easy integration into your building automation system of choice. MicroTech II benefits include:

actory integrated and tested

• F controller, sensor, actuator and unit options promote quick, reliable start-up and minimize costly field commissioning.

h-performance features and advanced control

• Hig options can quickly pay for themselves in saved energy costs and more comfortable classrooms.

• Select

from three control levels: stand-alone, master-

servant or network control.

network control applications, our Protocol

• For Selectability feature provides easy, low-cost integration of AAF-HermanNelson unit ventilators into most building automation systems.

• Flexible BAS

network communication options guard against controls obsolescence, keeping MicroTech II controls viable for the life of your AAF-HermanNelson equipment.

Three Control Levels

MicroTech II unit controllers provide the flexibility to operate AAF-HermanNelson unit ventilators on any of three levels:

• As st

• I

• Co

Stand-Alone Control

When operating in stand-alone mode, the MicroTech II controller performs complete room temperature and ventilation control. Units can be operated in occupied, unoccupied, stand-by, or bypass (tenant override) modes. Occupied/unoccupied changeover can be accomplished:

• Man

• Automa

and-alone units, with control either at the unit or

from a wall sensor.

n a master-servant relationship, where serv an t un its

follow the master unit for some or all functions.

ntrolled as part of a network using a centralized

building automation system.

ually by a unit-mounted occupied/unoccupied

switch.

tically by a unit-mounted occupied/unoccupied

time clock.

tomatically by a remote-mounted time clock that

• Au operates unit-mounted day/night relays.

If a school has more than one zone, separate, remote time clocks ar

e used to regulate each zone. In this case, the remote-mounted time clock energizes or deenergizes an external, 24-volt or 120-volt control circuit which operates the unit-mounted day/night relays in that zone.

Master-Servant Control

Designate the master and servant units and we will factory configure and install the controllers so they are set up for a local peer-to-peer network between units (leaving only the network wiring between these units to be field installed).

Servant units can be field-configured to be dependent or

ependent as follows:

ind

pendent servant units follow the master unit

• De

completely. They are ideal for large spaces that have even loads across the space (such as some libraries).

dependent servant units (default) use master

• In

setpoints and servant sensors. The servant follows the master unit modes, such as heat or cool, but has the flexibility to provide the conditioning required for its area within the space. Independent servant units perform better in spaces where loads vary from one area of the space to the other (such as stairwells or cafeterias).

Network Control

MicroTech II unit controllers provide easy integration into your building automation system of choice. All factoryinstalled options are handled by the unit controller. This simplifies the transmission of monitoring and setpoint data to the building automation system.

You select BACnet, LonTalk or Metasys N2 Open

unications to communicate control and monitoring

comm information to your BAS, without the need for costly gateways (see “Optional Communication Modules” on page 19). Unit controllers are L optional L

ONWORKS communication module.

ONMARK certified with the

Flexible network communication options via our Protocol

tability feature help you avoid control obsolescence

Selec over the life of your AAF-HermanNelson equipment.

AAF-HermanNelson Model AZ Unit Ventilators 13

MicroTech II Controls

Control Modes and Functions

AAF-HermanNelson unit ventilators equipped with MicroTech II unit controllers can be programmed to

perate in a variety of modes based on the current

o situation in the room and the status of the unit ventilator. Changes in mode can be triggered manually, via network signals, by sensor readings, or by date and time. External inputs and outputs can be used to change modes, communicate data to network contr ols or change the functional operation of the unit.

Occupancy Modes

MicroTech II unit controllers can be set up to change modes based on room occupancy. Four different occupancy modes are provided, as described below.

Occupied Mode

This is the normal daytime operation mode. The controller maintains a room set point using the out side air capability and other functions.

Note: For non-school applications, the unit can also be

configured to cycle the fan in response to the room load. In this case, the fan would normally be in the Off Mode until heating or cooling is required. The outside air damper is always closed when the fan is off. When the fan starts, the outside air damper opens to the required position, usually minimum position.

Economizer Modes

Economizer operation is facilitated by the outdoor air damper, which automa tically adjust s the above-minimum outside air position to provide free cooling when the outdoor air temperature is appropriate. Three levels of economizer control are available:

Basic Economizer Operation: The MicroTech II

controller compares the inside and outs ide temperatures. If the temperature comparison is satisfactory, then freeair economizer operation is used to cool the space. Reheat units also come configured with an indoor humidity sensor.

Expanded Economizer Operation: In addition to

comparing inside and outside temperatures, outdoor relative humidity is measured to calculate outside air enthalpy. Free economizer operation is used to cool the space. This helps to minimize the entrance of humid outside air.

Leading-Edge Economizer Operation: The MicroTech II

controller compares both indoor and outdoor temperatures and indoor and outdoor relative humidities to determine if free economizer operation can cool the space with non-humid outside air. This is a true enthalpy economizer.

Unoccupied Mode

This is the night setback operating mode, in which the unit responds to a new room set point and cycles to maintain the condition. The fan comes on when heating or cooling is needed and runs until the load is satisfied. The outdoor air damper is closed during this mode. When a cooling load is satisfied by a refrigerant system, the compressor is de-energized and the unit ventilator indoor fan continues to run for a fixed period of time to remove coldness from the evaporator coil.

Stand By Mode

In this mode, the unit maintains the occupied mode set point temperature with the outdoor air damper closed. The fan runs continuously unless it is configured to cycle in response to the load.

Bypass Mode

This is a tenant override operating mode in which the unit is placed back into the Occupied Mode for a predetermined time. The default is 120 minutes. Settings can be made in 1-minute increments from 1 minute to 240 minutes through ServiceTools™ (see page 23) or a network.

Night Purge Mode

Under this mode, the unit is configured to purge the room space for one hour for various reasons (odor or fume removal, drying, etc.).During Night Purge the outside air damper is open full and the fan is run on high speed. No “normal” heating or cooling takes place (the emergency heat set point is maintained) and the exhaust fan, if the room is so equipped, is signaled to turn on.

Freeze Prevention Mode

This mode helps protect the unit ventilator from freezing air conditions. Control functions vary depending on the type of temperature control used by the unit, as follows:

Face and Bypass Control Units

Upon sensing a potential freezing air tempera tu re condition leaving the heating coil, the unit will protect itself by shutting the outside air damper and opening the EOC valve. The fan continues to run to remove the cold air. Once accomp lished, the freezestat is reset, the outside air damper opens to the minimum position and the unit commences its normal mode of operation.

14 McQuay Catalog 1620

MicroTech II Controls

Valve Control Units

Upon sensing a potential freezing air temperature condition leaving the heating coil, the unit will automatically protect itself by shutting the outside air damper and opening the hot water valve to a mini mum of 50% (more if required to heat the room). The fan speed will be staged down to low speed and then turned off. When the freezestat is reset, the outside air damper opens to the minimum position and the fan runs at low speed for a minimum of 10 minutes. It then will stage up if needed to satisfy the room set point. This reduces the potential to overheat a room recovering from a potential freeze condition.

Note: Valve selection and coil sizing is critical for proper

operation. Face and bypass control is recommended for proper freeze protection.

Emergency Heat Mode

If the unit is left in a mode that does not normally allow heating (such as Off, Fan Only, Cool, or Night Purge) and the room temperature falls below 55°F, the unit will heat the space to above 55°F and then return to the previously set mode of operation. This mode of operation can be field configured and/or be disabled.

External Input Functions

The unit ventilator controller is provided with three (3) binary inputs that allow a single set of dry contacts to be used as a signal to it. Input signal choices are described below. Multiple units can be connected to a single set of dry contacts.

Note: Not all of the functions listed can be used at the same

time. The unit ventilator controller is provided with configuration parameters that can be adjusted to select which function will be used for these inputs where multiple functions are indicated below. For wiring examples see installation manual IM 747: MicroTech II Unit V

entilator Controller.

Unoccupied Input Signal

This input signals the unit ventilator controller to go into unoccupied or occupied mode. When the contact s close, the unit ventilator controller goes into unoccupied mode; when the contacts open, it goes into occupied mode. Additional variables can affect occupancy mode and override this binary input. See “Occupancy Modes” on page 14.

Dewpoint/Humidity Input Signal (Optional)

This input signals the unit ventilator controller to go into active dehumidification mode. When the contacts close (high humidity) the controller will go into active

dehumidification; when the contacts open (low hu midity) it will stop active dehumidification.

Remote Shutdown Input Signal

This input signals the unit ventilator controller to go into shutdown mode. When the contact s close, the controller goes into shutdown mode; when the contacts open, it returns to normal operation.

Ventilation Lockout Input Signal

This input signals the unit ventilator controller to close the outdoor air damper. When the contacts close (ventilation lockout signal) the controller closes the outdoor damper; when the contacts open, it returns to normal outdoor damper operation.

Exhaust Interlock Input Signal

This input signals the unit ventilator controller that an exhaust fan within the space has been energized. The controller then repositions the outdoor air damper to a user-adjustable minimum position. When the contacts close (exhaust fan on signal) the controller uses the value defined by the Exhaust Interlock OA Damper Min Position Setpoint as the new minimum outdoor air damper position regardless of the indoor air fan speed. When the contacts open, it returns to normal outdoor damper operation.

External Output Functions

The unit ventilator controller is provided with three (3) binary outputs to perform the functions described below. These are relay type outputs that are intended to be used with signal level voltages only (24 VAC max).

Note: Not all of the functions listed can be used at the same

time. The unit ventilator controller is provided with configuration parameters that can be adjusted to select which function will be used for these outputs when multiple functions are indicated below. For wiring examples, see installation manual IM 747: MicroTech II Uni

t Ventilator Controller.

Lights On/Off Signal

This relay output provides one set of NO dry contacts that can be used to signal the operation of the room lights. When the unit ventilator controller is in occupied, standby or bypass occupancy modes, the relay output will signal the lights on (contacts closed); when the controller is in unoccupied occupancy mode the relay output will signal the lights off (contacts open).

AAF-HermanNelson Model AZ Unit Ventilators 15

MicroTech II Controls

Fault Signal

This relay output provides NO, NC, and Common connections that can be used to signal a fault condition. When a fault exists, the unit ventilator controller energizes this relay output. When the fault or faults are cleared, it de-energizes this relay output.

Exhaust Fan On/Off Signal

This relay output provides one set of NO dry contacts that can be used to signal the operation of an exhaust fan. When the outdoor air damper opens more than the Energize Exhaust Fan OA Damper Setpoint, the relay output will signal the exhaust fan on (contacts closed). When the outdoor damper closes below this setpoint, th e relay output will signal the exhaust fan off (contacts open).

Auxiliary Heat Signal

This relay output provides one set of NO dry contacts that can be used to operate an auxiliary heat device. The unit ventilator controller by default is configured to operate a NO auxiliary heat device (de-energize when heat is required) such as a wet heat valve actuator with a spring setup to open upon power failure. However, the Auxiliary Heat Configuration variable can be used to set the controller to use an NC auxiliary heat device (energize when heat is required) such as electric heat.

fan operation under normal operating conditions, in conjunction with our GentleFlo fan technology contributes to a very quiet classroom environment.

Demand-Controlled Ventilation (Optional)

AAF-HermanNelson unit ventilators can be equipped to use input from a CO based on actual occupancy instead of a fixed design occupancy. This Demand Controlled Ventilation (DCV) system monitors the amount of CO students and teachers so that enough fresh o utdoor air is introduced to maintain good air quality. The system is designed to achieve a target ventilation rate (e.g., 15 cfm/person) based on actual occupancy.

By using DCV to monitor the actual occup a ncy pattern in

oom, the system can allow code-specific levels of

a r outdoor air to be delivered when needed. Unnecessary over-ventilation is avoided during periods of low or intermittent occupancy.

With DCV you can be confident that your school is

eting ventilation standards for Indoor Air Quality and

me that your students are receiving adequate air to be attentive to instruction. At the same time, you are saving money in early morning hours, in between classes, or after hours when classrooms are heated and cooled but not always fully occupied.

Acceptance By Codes And Standards

controller to ventilate the space

produced by

Advanced Control Options

MicroTech II controls make possible a number of advanced control options that can quickly pay for themselves in saved energy costs and more comforta ble classrooms, as described below .

Part Load Variable Air Control

Part Load Variable Air control can be used in conjunction with face and bypass damper temperature control to automatically adjust the unit ventilator fa n spee d ba se d upon the room load and the room-temperature PI control loop. This MicroTech II control option provides higher latent cooling capabilities and quieter operation during non-peak load periods by basing indoor fan speed upon room load.

During low-load or normal operation (about 60% of the time) the fan will operate increases to an intermediate demand, the fan will automatically shift to the medium-speed setting. Under near-design or design-load conditions, the fan will operate on high speed. A built-in, 10-minute delay helps minimize awareness of fan speed changes. Low-speed

on low speed. When the load

ASHRAE Standard 62-2004 Ventilation for Indoor Air Quality recognizes CO controlling ventilation based on occupancy. The ASHRAE standard has been referenced or adopted by most regional and local building codes. This standard references ventilation on a per-person basis.

Using CO amount of outside air delivered into a room but will maintain the per-person rate. For example, if a classroom is designed for 30 students, the ventilation rate is 450 cfm (30 students X 15 cfm/student) . However, when there are only ten students in the classroom, the CO

X 15 cfm/student). A minimum base ventilation rate (typically 20% of design levels) is provided when in the occupied mode. This provides outdoor air to offset any interior source contamination while allowing for proper space pressurization.

control will sometimes lower the absolute

control will adjust ventilation to 150 cfm (10 students

based DCV as a means of

Active Dehumidification Control (Reheat)

In high-humidity applications where valve-controlled, reheat units are used, the Active Dehumidification Control (ADC) sequence should be considered. During

16 McQuay Catalog 1620

MicroTech II Controls

excessive humidity conditions, a humidity sensor directs the unit to continue cooling past the room setpoint to remove excess moisture. Hydronic heat or electric heat is then used to reheat the discharge air to maintain acceptable room temperatures.

MicroTech II controls minimize th

e amount of reheat needed to maintain relative humidity below a preset limit. Reheat is used only when required and in the most energy-efficient manner possible.

Active Dehumidification comes standard on units

quipped with MicroTech II controls, a reheat

figuration and valve-control temperature modulation.

con The MicroTech ADC humidity sensor is unit-mounted. It issues a signal proportional to the classroom’s humidity level (unlike humidistats which issue an open-close signal). This enables a control sequence that manages both the temperature and the relative humidity.

When the relative humidity exceeds a preset value, the

efrigerant cooling activates to dehumidify the mixture of

r outdoor and return air entering the cooling coil. The reheat modulating water valve then opens, or electric heat is engaged, to reheat the air leaving the cooling coil, as required to maintain the classroom setpoint.

Active dehumidification starts when the indoor relative

umidity exceeds the preset relative humidity upper

h setpoint and continues until the room humidity falls 5% below the endpoint. During active dehumidification, economizer operation is disabled (and the outdoor air damper is reset to its minimum position) unless the outdoor air temperature is below 55°F. It is maintained until dehumidification is completed. When the indoor humidity level is satisfied, the MicroTech II controller

reverts to its normal sequences to satisfy the classroom temperature setpoint.

DX System Control

The unit ventilator controller is configured to operate the compressor as secondary (mechanical) cooling when economizer cooling is available, and as primary cooling when economizer cooling is not available. Additional DX control features include:

Compressor Envelope: This helps protect the

compressor from adverse operating conditions that can cause damage and or shortened compressor life. It ends compressor operation if coil temperatures exceed the defined operating envelope.

Compressor Cooling Lockout: The unit ventilator

controller is configured to lock out compressor cooling when the outdoor air temperature falls below the compressor cooling lock out setpoint. Below this temperature setpoint only economizer cooling will be available.

Minimum On And Off Time: The unit ventilator controller

is provided with minimum-on and minimum-off timers to prevent adverse compressor cycling (3-minutes default).

Compressor Start Delay Variable: This variable is

intended to be adjusted as part of the start-up procedure for each unit. It is used to prevent multiple unit compressors from starting at the same time af ter a power failure or after an unoccupied-to-occupied changeover. Each unit should be configured at start-up with a slightly different (random) delay, or groups of units should be provided with different delays.

AAF-HermanNelson Model AZ Unit Ventilators 17

MicroTech II Controls

System Components

The main components of the MicroTech II system are:

• The Unit Ventilator Controller (UVC)

• The Local User Interface (LUI)

• Optional plug-in network communication modules

In ad

dition, unit ventilators equipped with MicroTech II

rollers feature factory-mounted sensors and

cont actuators for system control and feedback.

Unit Ventilator Controller

The MicroTech II UVC is a DDC, microprocessor-based controller designed to provide sophisticated comfort control of an economizer-equipped AAF-HermanNelson unit ventilator. In addition to normal operating control, it provides alarm monitoring and alarm-specific component shutdown if critical system conditions occur. Each UVC is factory wired, factory programmed and factory run-tested for the specific unit ventilator model and configuration ordered by the customer.

Figure 17. MicroTech II Control Board

Terminal Connections

Plug-In Control Module

Figure 18. User Interface To uc h Pad

The User Interface has individual touch-sensitive printed circuit board mounted buttons, and comes with a built-in menu structure (Hidden Key and Password Protected) to change many of the common operating variables.

Four Operating Mode States

Four different user operating mode st ates can be chosen on the LUI:

Heat: Heating and economizer operation only. Cool: Cooling and economizer operation only. Fan Only: Fan only operation.

Local User Interface

A built-in LUI touch pad with digital LED Display is located in the right hand compartment below the top rig ht access door. In addition to the Operating Mode States and Fan Functions, the Touch Pad will digitally display:

he room set point temperature.

• T

• The current room temperature.

• Any fault code for quick diagnostics at the unit.

Auto: The unit automatically switches between heating,

cooling and economizer operation to satisfy the room load conditions. The current unit state is also displayed.

Four Fan States

Four fan states are provided on all units: high, medium low and Auto speed modulation. The Auto speed function (part load, variable air) varies the fan speed automatically to meet the room load whether the unit is in heating, cooling or economizer mode.

All this is accomplished with NEMA frame motor. A built-i n 10-minute delay helps minimize awareness of speed changes. During low-load or normal operation (about 60% of the time) the fan will operate at low speed. The low speed operation, along with GentleFlo fan technology, contributes to a very quiet classroom environment.

When the load increases to an intermediate demand, the

cally shifts to the medium speed setting. At

fan automat near-design or design-load conditions the fan will operate on high speed.

With four fan states and GentleFlo fan technology, there

o need to oversize units or worry about

is uncomfortable conditions.

a standard, single-speed

18 McQuay Catalog 1620

MicroTech II Controls

Optional Communication Modules

Optional communication modules provide control and monitoring information to your building automation system without the need for costly gateways. Available communication protocols include BACnet, LonTalk and Metasys N2 Open. The communication modules for each are described below.

Figure 19. Typical 2" x 4" Communication Module

BACnet MS/TP Communication Module

This module allows the UVC to inter-operate with systems that use the BACnet (MS/TP) protocol with a conformance level of 3. It meets the requirements of the ANSI/ASHRAE 135-1995 standard for BACnet systems.

LONWORKS SCC Communication Module

This module supports the LONWORKS SCC (Space Comfort Communication) profile number 8500-10. Unit controllers are LonMark certified with this optional

ONWORKS communication module.

Metasys™ N2 Communication Module

This module provides N2 Open network communication capability to the UVC for communication with Johnson Metasys systems.

Sensors

The UVC is configured to use passive Positive Temperature Coefficient (PTC) unit-mounted and wallmounted sensors. These sensors vary their input resistance to the UVC as the sensed temperature changes.

Figure 20. Wall-Mounted Temperature Sensors

Standard Expanded

Standard Sensor: This sensor has no remote setpoint

adjustment capability.

Expanded Sensor: This sensor has a remote room

setpoint adjustment of ±3°F (±1.5°C) from the room setpoint established on the unit ventilator’s local user interface touch pad. Five temperature settings are provided on each side of center.

Humidity Sensors

On units equipped with humidity sensors, the UVC is configured to use a 0-100% RH, 0 VDC, capacitive humidity se

nsor. Humidity sensors are available as unitmounted only. The humidity sensors are used with units capable of active dehumidification, or with units using an outdoor enthalpy economizer or an indoor/outdoor enthalpy economizer.

CO2 Sensor for Demand Controlled Ventilation

On units equipped for Demand Controlled Ventilation (DCV) the UVC is configured to use a 0-2000 PPM, 0-10 VDC, single beam absorption infrared gas sensor. CO

sensors are available as unit mounted only. An air collection probe (pitot tube and filter) is installed in the return air of the unit.

Figure 21. CO2 Sensor For Demand Control Ventilation

Remote Wall-Mounted Temperature Sensors

MicroTech II unit ventilators offer three choices for remote wall-mounted room sensors (Figure 20). Each has a tenant override capability and comes with an international, quick-

AAF-HermanNelson Model AZ Unit Ventilators 19

fastening connection capability.

MicroTech II Controls

MicroTech II Sensor and Component Locations

Figure 22. MicroTech II Sensor and Component Locations

1 MicroTech II Unit Ventilator Controller (UVC):

(Located Beneath the Local User Interface Panel). Factory mounted and run tested, microprocessorbased DDC control device capable of complete, Stand-alone unit control, Master/Slave control, or incorporated into a building-wide network using an optional plug-in communication module. The UVC supports up to 6 analog inputs, 12 binary inputs, and 9 binary outputs. The UVC expansion board supports up to 4 additional analog inputs and 8 additional binary outputs. Master/Slave units have the controller factory configured for a local peer-to-peer network between these units (network wiring between thes e units needs to be field installed). Optional network

communication is provided via plug-in communication modules that connect directly to the UVC.

2 Communication Modules (optional): (Lo

Beneath the Local User Interface Panel). Plug -in network communication module that is attached to the UVC via a 12-pin header and 4 locking standoffs. Available communication modules:

ing Automation and Control Netw

• Build net™) Master Slave/Token Passing

ork (BAC-

(MS/TP) Allows the UVC to inter-operate with systems that use the BACnet (MS/TP) protocol with a conformance level of 3. Meets the requirements of ANSI/

AE 135-1995 s

ASHR

tandard for BACnet systems.

ated

20 McQuay Catalog 1620

MicroTech II Controls

• LONWORKS™ compliant Space Comfort Controller

(SCC) – Supports the L

ONWORKS SCC profile num-

ber 8500-10.

etasys™ N2 Open – Provides N2 Open network

• M communication capability to the UVC.

3 Local User Interface (LUI):

The LUI provides a unit mounted interface which indicates the current unit operating state and can be used to adjust the unit ventilator operating parameters (operating mode, temperature set points, fan speed, and occupancy mode). The LUI features a 2-digit display, 7 keys (1 key is hidden), and 9 individual LED indicators.

4 Tenant Override Switch Pr

ovides a contact closure that causes the unit to enter the “Occupied” operating mode for a set time period (default = 120 minutes).

5Time Clock (

optional on stand-alone units only) Factory mounted 7 day/24 hour, digital time clock with up to 20 programs to sequence the unit ventilator through occupied and unoccupied modes in accordance with a user programmed time schedule.

6 External Signal Connection Plugs: (L

ocated Beneath the Local User Interface Panel). Three multipin plugs are factory provided and pre-wired with amp plug connections that plug into the wall sleeve. Provided for field wiring of :

ote Wall Mounted Temperature Sensor

• Rem

(optional accessory).

rnal Input Signals (by others): unoccupied,

• Exte

remote shutdown, ventilation lockout, dew point/ humidity (night time operation) or exhaust interlock signals.

rnal Output Options (by others): lights on/off,

• Exte

fault indication signal, exhaust fan on/off or au xiliary heat signal.

Note: Not all external signal options can be used

simultaneously and may not be available on all software models. Refer to the “UVC Input and Output Tables” in IM 747 for available options.

7 Motor Speed Transformer: (Located Beneath the

Local User Interface Panel). Multi-tap autotransformer provides multiple fan motor speed control through the LUI.

8 Unit Main Power “On-Off” Switch (not shown):

Shipped

with the wall sleeve accessory, the “On-Off” switch disconnects the main power to the unit for servicing or when the unit is to be shut down for an extended period of time.

9 Fuse(s) - Fa

n motor and controls have the hot line(s)

protected by factory installed cartridge type fuse(s).

10 Control Transformer - (L

ocated Beneath the Local User Interface Panel). 75 VA 24-volt NEC Class 2 transformer for 24 volt power supply.

11 Outdoor Air/Return Air Damper Actuator -

Direct coupled, floating point (tristate) actuator that spring returns the outdoor air damper to the closed position upon a loss of power.

12 Face and Bypass Damper Actuator - Direc

t coupled, floating point (tristate) actuator that is nonspring returned (Model AZQ only , other unit s are valve control).

13 Hydronic Coil Low Air T

emperature Limit (T6

freezestat) – Factory installed on all units with hydronic (water) coils. The T6 freezestat cuts out at 38ºF (+/- 3ºF) and automatically resets at 45ºF (+/3ºF).

14 Indoor, Direct Expansion (DX) Coil Refrigerant

emperature Sensor – The sensor is installed on the

unit ventilator’s indoor refrigerant coil on the right hand side of the coil “u-bend”. It is used to sense low refrigerant temperatures on the indoor coil.

15 Outdoor, Direct Expansion (DX) Coil Refrigerant

emperature Sensor - The sensor is installed on the

unit ventilator’s outdoor refrigerant coil on the right hand side of the coil “u-bend”. It is used to sense the refrigerant temperature on the outdoor coil.

16 Room Temperature Sensor - Th

e unit mounted sensor is located in the sampling chamber (front, center section) where room air is continuously drawn through for prompt response to temperature changes in the room. A remote wall mounted temperature sensor is available for remote room temperature sensing. (optional).

17 Discharge Air Temperature Sensor – The

sensor is located on the second fan from the right to sense discharge air temperatures.

18 Outdoor Air Temperature Sensor –

The sensor is located in the outdoor air section of the unit before the outdoor air damper. With network applications, the unit mounted sensor can be overridden by a remote sensor through the network.

19 Outdoor Air Humidity Sensor (o

ptional, standard with expanded and leading edge controls) - Unit mounted humidity sensor for units using expanded outdoor enthalpy economizer or Le ad ing Edge in doo r/ outdoor, true enthalpy comparison economizer. The sensor is located in the outdoor air section of the unit before the outdoor air damper. With network applications, the unit mounted sensor can be overridden by a remote sensor through the network.

AAF-HermanNelson Model AZ Unit Ventilators 21

MicroTech II Controls

20 Room Humidity Sensor (optional, standard with

expanded controls) – Unit mounted humidity sensor for units capable of passive or active dehumidification (Reheat) or with units using Leading Edge indoor/ outdoor, true enthalpy comparison economizer. The sensor is located in the sampling chamber (front, center panel) where room air is continuously drawn through for fast response to humidity changes in the room. With network applications, the unit mounted sensor can be overridden by a remote sensor thro ugh the network.

(

21 CO2 Sensor

optional) – Unit mounted, single beam absorption infrared gas sensor with a sensing range of 0 – 2000 ppm and voltage output of 0 to 10 VDC (100 ohm output impedance). The pitot tube sensing device is located in the unit ventilator's return air stream. The optional CO2 sensor is used with the UVC's Demand Control Ventilation feature to vary the amount of outside air based on actual room occupancy. With network applications, the unit mounted sensor can be overridden by a re mote sensor through the network.

22 Control Valve(s) (n

shown) – Optional accessory valve(s) may be either 2-position "End of Cycle" (model AZQ) or modulating (model AZU and AZR), to control the quantity of water through the coil. Available in 2-way or 3-way configurations. Spring return actuators are required for all hot water and steam heating valves. All heating valves are normally open.

Outdoor Air/Return Air Damper (OAD) Actuator

The UVC is configured to operate a floating-point (tristate) direct-coupled actuator for the outdoor air damper. This actuator provides spring-return operation upon loss of power for positive close-off of the outdoor air damper. To determine damper position, the UVC uses a separate, factory-preset, configurable setting for each actuator's stroke time.

Figure 24. Outdoor Air Damper Actuator

2-Position End-of-Cycle Valve Actuators (Optional)

On units equipped with 2-way or 3-way, end-of-cycle (EOC) valves, the UVC is configured to operate 2position End-Of-Cycle (EOC) valve actuators (Figure 25). Spring return actuator s are used fo r all End of Cycle (EOC) valves. All wet heat EOC valves are

rmally open.

Figure 25. End of Cycle Valve Actuator

Actuators

Face & Bypass Damper Actuator

On units equipped with face & bypass damper control, the UVC is configured to operate a floating-point (tristate), direct-coupled, face & bypass damper actuato r . To determine the modulating damper position, the controller uses a separate, factory-preset, configurable setting for each actuator's stroke time.

Figure 23. Face & Bypass Damper Actuator

22 McQuay Catalog 1620

MicroTech II Controls

Modulating Valve Actuators (Optional)

On units equipped with modulating valves, the UVC is configured to operate floating-point (tri-state) actuators for modulating 2- way and 3-way valves (Figure 26).

Figure 26. Modulating Valve Actuator

2-Way Valve 3-Way Valve

Spring return actuators are used for all modulating valves. All wet heat valves are normally open.

To determine modulating valve position

the UVC uses a separate factory preset, configurable setting for each actuator's stroke time. For accuracy of actuator positioning, the UVC is provided with an overdrive feature for the 0% and 100% positions and a periodic (12-hour) auto-zero PI control loop for each modulating actuator.

Optional Time Clock For Stand-Alone Units

As an option, stand-alone, non-servant un it ventilators can be factory-equipped with a unit-mount ed, di g ital, 24hour/7-day time clock with 20 programs (Figure 27). The clock is factory-wired to automatically o

ccupied or unoccupied mode based upon its schedule.

Features of this clock include:

• Large keys with circular programming for easy

hedule setup

• An LCD disp

lay

• Manual 3-way override (On/Auto/Off)

• Capacitor backup to retain pr ogram memory during

wer outages.

place the unit into

Figure 27. Optional Time Clock

ServiceTools™

ServiceTools for MicroT ech II Unit Ventilators is a CD containing software for operation on a personal computer. This software provides a visual schematic of the unit, a pictorial representation of the sequence of operation and enables the service technician to:

onitor equipment operation.

• M

• Configure network communications.

• Diagnose unit operating problems.

• Download application code and configure the unit.

is software is a purchased tool for service technicians

and will run

on PCs with Windows 2000 (SP2), and NT4.0 (SP6) and XP (SP1) operating systems. This tool is highly recommended for startup and servicing. (It may be required for startup and/or servicing, depending upon unit integration and other requirement s.) It has no BAS functions, such as scheduling or trending, and it cannot serve as a Work Station Monitoring package.

ServiceTools comes with a service cable having two

rface conn

inte

ections:

• A 12-pin connection to the main control board.

• A 3-pin connection to the optional communication

ules.

mod

98 (Second Edition),

AAF-HermanNelson Model AZ Unit Ventilators 23

Accessories

Wall Louvers & Grilles

The 16-gauge QS 5052 mill finish aluminum louver frame is divided in half horizontally, with make-up and discharge-air stream sections to reduce air recirculation within the vertical louver blade. The upper half of the louver has a blockoff on the exterior side to increase discharge air velocity and improve the throw of leaving air.

The vertical louver can be ordered with flanges that are

tached on the outside of all four sides of the lo uver,

a resulting in a vertical dimension of 30" (762 mm). Weep holes exist behind the bottom flange of the louver. A 1/2" (13 mm) square aluminum wire mesh (bird screen) is provided on the interior surface of the louver.

The vertical louver is fabricated from 20-gauge QS 5052

finish aluminum. The single piece blade has a turned

mil edge along the entering and leaving surface to reduce

Figure 28. Typical W a ll Lo uver and Grille

Factory Mounted

Bird Screen

Fasteners

Frame

Optional

Flanges

Splitter Lines Up with Wall

Sleeve Splitter

visibility of the outdoor coil and fan section, and adds rigidity to the blade. The 72° offset bend near the middle of the blade creates an air-path turn that minimizes moisture carryover, with a total blade depth of 2¼" (57 mm) in direction of airflow .

colors

The louver is available in the following

• Natural Aluminum finish (paintable QS 5052 Alumin

um)

• Autumn Brown - thermosetting urethane powder coat

aint electrostatically applied and oven-cured to

p provide correct chemical cross-linking.

• Dark Bronze - thermosetting urethane powder coat

aint electrostatically applied and oven-cured to

p provide correct chemical cross-linking.

• Clear Anodized Aluminum finish

Figure 29. Vertical Blade Louver Outside View, Without

Flange

Discharge Air

Outside View

Condenser

Information

Labels

Louver Blade

Bottom Flange

Bottom

Drain Notch

Optional Factory

Exterior Grille

Mechanical

Fasteners

Mounted

Condenser

Inlet Air

Figure 30. Vertical Blade Louver Inside View, Without

Flange

Bird Screen on

Side Toward Unit

Inside View

Condenser

Discharge Air

Condenser

Inlet Air

Louver with

Weep Holes

24 McQuay Catalog 1620

Accessories

VentiMatic™ Shutter Room Exhaust Ventilation

Outdoor air introduced by the unit ventilator must leave the room in some way. In some states, exhaust vent s are required by law or code to accomplish this. The Ventimatic shutter is a more economical solution to the problem.

The Ventimatic shutter is a continuously variable, gravity-

tuated room exhaust vent (Figure 31). It operates in

a direct response to positive static ai when ventilation air is brought into the room by the unit ventilator. It is a “one-way” shutter that opposes any flow of air into the room.

Figure 31. Ventimatic Shutter

The Ventimatic Shutter’s ability to exhaust only the amount of air required results in considerable energy savings. In the heating mode, the unit ventilator will be able to bring in only the required percent minimum outdoor air. Unlike systems that rely on powered exhaust, no energy will be wasted heating excess outdoor air . In the cooling mode, the unit ventilator will be able to bring in 100% outdoor air for full natural or free cooling when it is energy effective.

Since it is not powered, Ventimatic inherently silent. Unlike other non-powered vents, it opens at an extremely low positive pressure (0.005"). Its shutter flaps are made of temperature-resistant glass fabric impregnated with silicone rubber for flexibility and

r pressure created

Front (Indoor Side)Back (Outdoor Side)

Shutter’s operation is

long life. This fabric retains its original properties down to

-50°F.

Ventimatic Installation

The Ventimatic Shutter should be mounted on the same wall as the unit ventilator. This neutralizes the effect of wind pressure forcing excess air into the room through the unit ventilator louver. That’s because the wind pressure will also keep the Ventimatic Shutter closed and prevent room air from escaping. Since the existing room air cannot leave, excess air from the wind gust will not enter. (In contrast, a powered exhauster would “assist” the wind’s effect.) Same-wall mounting also minimizes “short circuiting” of air flow that could occur with opposite-wall mounting.

The Ventimatic Shutter is generally mounted on an AAF-

HermanN then used for exhaust (Figure 32). For large unit ventilators, two Ventimatic Shutters may be mounted

by side on the same wall louver to promote

sid adequate exhaust air capacity. The size and appearance of wall louvers and grilles used for unit ventilators and for Ventimatic Shutters are identical and present an architecturally coordinated and pleasing installation.

An ideal method of integratin with the unit ventilator is to locate the shutter behind a matching open-shelf or closed-shelf storage cabinet mounted next to the unit ventilator . For example, 48-inchlength wall louver can be accommodated behind a 4foot-high storage cabinet. The cabinet should be ordered with a slotted-type kick plate to provide a concealed exhaust air path to the shutter. This combination will enable a complete, integrated, energy-efficient HVAC and room exhaust system.

lson wall louver (ordered separately) which is

e Ventimatic Shutter

g th

Figure 32. Ventimatic Shutter Installation

Aluminum Exterior

Louver

Two Shutter Assemblies Mounted on One Louver

Aluminum Exterior Grille (optional)

Center Cover

AAF-HermanNelson Model AZ Unit Ventilators 25

Steel Interior Grille (optional)

Grille (optional)

Aluminum Louver

Baffle Plate

Accessories

Storage Cabinets, Sink & Bubbler

AAF-HermanNelson storage cabinets are designed to complement our classroom unit ventilators. They are made from heavy-gauge steel and finished with environmentally friendly, thermosetting urethane powder paint that is available in a pleasing array of matching architectural colors.

Storage Cabinets

Shelving cabinet tops are furnished with a textured, nonglare and scuff-resistant charcoal bronze electrostatic paint. Optional laminate tops are available for these cabinets and for field-supplied and installed countertops. Other features include:

• Adjust

• Optional easy sliding doors with bottom glide track for

• Door pulls added for convenience and finished

Figure 33. Cabinet With Shelves

able kick plates with leg levelers are standard on

all un

its and functional accessories. European cabinet design has adjustable leg levellers on each corner that adjust to compensate for variations in the floor.

able-height metal shelves for flexible storage

ace (Figure 33). Shelves can be adjusted without tools by repositioning the four co clips.

od alignment (Figure 34). Bottom glide track

go prevents door bottom intrusion into the storage space.

nal door locks.

Optio

pearance.

ncealed shelf holding

Sink & Bubbler Cabinet

Sink & bubbler cabinets have a one-piece stainless steel top with stainless steel bowls, a raised front lip, and formed back and end splash boards (Figure 35). You have a choice of single or double bowls and optional

locks to conceal storage and piping. The adapter

do back top, when furnished, has a charcoal textured finish.

Figure 35. Cabinet With Sink And Bubbler

End Panels

One-inch end panels are typically used to finish off stand-alone floor units. Six-inch end panels with kick plates can be used to provide extra space needed for piping (Figure 36). All end panels are individually wrapped in plastic and boxed to help prevent damage

rin

g construction.

Figure 36. End Panels

6" End Panel

Figure 34. Cabinet With Sliding Doors

Filler Sections

Filler sections can be used as spacing between cabinets, walls and unit ventilators.

26 McQuay Catalog 1620

Application Considerations

Why Classrooms Overheat

Overheated classrooms occur every day in schools in every area of the country. The most serious result is their detrimental effect on students’ ability to concentrate and learn. Research has determined that the ability to learn and retain knowledge decreases rapidly as the temperature exceeds recommendations. Overheated rooms also represent wasted fuel, resultin g in exc es sive operating costs.

Correcting an overheating problem in an existing building

ficult and expensive. It calls for redesign and

ry dif

is ve alteration of the heating and ventilating system, necessitating considerable renovation. This potential problem should be recognized, understood and planned for when heating and ventilating systems are designed for new and existing buildings.

Schools Have Special Needs

Schools have unique heating and ventilating needs, in large part because of their variable occupancy and usage patterns. Fewer cubic feet of space is provided per student in a school building than in any other type of commercial or public building. School classrooms are typically occupied only six hours a day, five days a week, for only three-fourths of the year, with time out for vacations. All in all, this represents approximately 15% of the hours in a year that a classroom is occupied.

To understand the overheating problem in schools, one

first realize that the excess heat comes from what

must is commonly termed “uncontrolled heat sources.” To gain some perspective on how this affects heating and coo ling decisions, let’s take a look at a typical classroom in the northern section of the midwestern United States.

Suppose we have a classroom that is 24 by 38 feet with 10-foot ceilings

and 100 square feet of along the outside wall. At an outside temperature of 0°F and a desired room temperature of 72°F, let’s assume the normal amount of heat loss from the room to the outside is 55,000 BTUs per hour.

As the outside temperature changes, so does the

ount of heat that the room loses. This is represented

a in Figure 37 by Room Heat Loss Line A, which ranges from 55,000 BTU per hour at 0°F outside air temperatur e

to zero BTU

70°F. Obviously, if the heating system were the only source of heat in the classroom, the solution would be simple: The room thermostat would cause the heating system to supply exactly the amount of heat required to maintain the room at the thermostat temperature setting. In reality, the introduction of excess heat from a variety of uncontrolled sources makes the challenge considerably more complex.

window area

Figure 37. Heat Gain vs. Heat Loss In Occupied

60,000

50,000

40,000

30,000

20,000

Room Heat Loss, BTU/HR

10,000

As this chart illustrates, even in very cold weather an occupied classroom is more likely to require cooling than heating.

Classrooms

ROOM HEAT LOSS LINES

B C D

-10 0 10 20 30 40 50 60 70

Outside Air Temperature, °F

Temperature On Room Heat Loss Line Above Which Cooling Is Always Required

10,000 BTU/HR

}

Possible Heat Gain From Sun, Direct & Reflected

8,500 BTU/HR

}

Heat Gain From Lights

7,800 BTU/HR

}

Heat Gain From Students

Heat From Students

Body heat generated by students in a classroom is one of the three primary sources of uncontrolled heat. In a typical classroom of 30 students, the amount of heat given off at all times will vary according to factors such as age, activity, gender, etc. A conservative estimate is 260 BTU per hour per pupil. Multiply this by 30 and you get a total of 7,800 BTU per hour added to the room by the students alone. This excess heat is noted in Figure 37 as “Heat Gain from Students.”

Heat Gain From Lights

Heat emitted by the lighting system constitutes a second uncontrolled heat source. Artificial lighting is needed in most classrooms even during daylight hours to prevent unbalanced lighting and eye strain. A typical classroom requires approximately 2,500 watts of supplemental lighting to provide properly balanced lighting. Fluorescent lights add heat to the room at the rate of 3.4 BTU per watt per hour , or a tot al of 8,500 BTU per hour. This extra heat is represented in Figure 37 as “Heat Gain from Lights.”

Add the heat gain from lighting to the 7,800 BTU

odu

intr

ced by student body heat and we now have an extra 16,300 BTU/HR being introduced into the classroom by uncontrolled sources. This heat gain remains constant regardless of the outdoor air temperature.

AAF-HermanNelson Model AZ Unit Ventilators 27

Application Considerations

Solar Heat Gain

The sun is a third uncontrolled source of heat. And, because it is neither positive nor constant, calculating its contribution to the overall heat gain is difficult. Solar heat gain can be the worst offender of the three in classrooms with large windows. Indirect or reflected solar radiation is substantial even on cloudy days, even in rooms with north exposure, as a result of what is termed “skyshine.”

To get an idea of the potential effect of the sun, let’s

ssume that the solar heat gain in our hypothetical

a classroom will peak at 240 BTU/HR per square foot of glass area. If we then assume a glass area of 100 square feet and at least 100 BTU/HR per square foot of glass for solar heat gain, we can calculate a very conservative estimate of 10,000 BTU/HR heat gain through windows. If we add this to the heat from the lights and body heat, total heat gain adds up to 26,300 BTU/HR from sources other than the heating and ventilating system. This is indicated in Figure 37 by the top horizontal line, which intersects Room Heat Loss

ine A at approximately 37°F. This is a reasonable

L estimate of the maximum uncontrolled heat gain that can be received in the typical classroom from these common heat sources.

The Analysis

From Figure 37 it is evident that, at an outside temperature of 48°F or higher, the he students and classroom lighting is sufficient to cause overheating. This is true even if the classroom is occupied at night when solar heat gain is not a factor. But, since classrooms are occupied during the day, solar addition provides heat in varying amounts even in classrooms with north exposures. Consequently, the heating and ventilating system in our typical classroom must provide cooling at all times when the outdoor temperature is above 48°F and at any time during colder weather when the solar heat gain exceeds room heat loss.

If we assume an average winter temperature of

proximately 33°F in the region where our typica l

ap classroom is located, we know that, half of the time, both night and day, the outside temperature will be above 33°F. However, since it is generally warmer during the day, when school is in session, the heating and ventilating system will be required to provide cooling for this classroom during much of the time that the room is occupied.

In this example, we’ve assumed that our classroom had

room heat loss of 55,000 BTU/HR at a design outdoor

a air temperature of 0°F (Room Heat Loss Line “A”). Bear

at given off by 30

in mind, however, that the recen t trend in “energy-saving” building design often results in rooms with lower room heat loss, as indicated by Room Heat Loss Lines “B”, “C” and “D.” At 0°F design outdoor air temperature:

om “B” has a room heat loss of 45,000 BTU/HR,

• Ro

om “C” has a room heat loss of 35,000 BTU/HR,

• Ro

om “D” has a room heat loss of 25,000 BTU/HR.

Note the lowering of the temperature above which cooling will decreases.

We’ve noted that cooling is alway “A” when outdoor air temperatures exceed 48°F. In Classroom “B,” “C,” and “D” cooling is always required when outdoor temperatures exceed 44°, 36°and 23°F, respectively (Figure 37).

Now that we understand the reason for classrooms

rheating, the solution is simple: The heating and

ove ventilating system must provide cooling to take care of the heat given off in the classroom by uncontrolled heat sources.

always be required as the room heat loss

s required in Classroom

Cooling The Classroom

The AAF-HermanNelson Unit Ventilator has become a standard for heating and ventilating systems in schools because it provides the solution for overheating classrooms. The unit ventilator cools as well as heats. During the heating season the outdoor air tempe rature is nearly always below the desired room temperature. It stands to reason then that the outsid e air should be use d to provide the cooling necessary to keep classrooms down to thermostat temperature.

The classroom unit ventilator does just that. By

rporating an automatically controlled outdoor air

inco damper, a va riable quantity of outdoo r air is introduced in the classroom, metered exactly to counteract overheating. Since our problem is more one of cooling than of heating, it is evident that more than just the room heat loss must be determined to design a good heating and ventilating system. The cooling requirements should be assessed as well, and the free-cooling capacity of the equipment specified along with the heating capacity required. If this is done, the optimum learning temperature can be maintained in each classroom.

28 McQuay Catalog 1620

Application Considerations

Meeting IAQ Requirements

Good indoor air quality (IAQ), which is important in the home and at work, is no less important to students and faculty in schools. For the past several years, efforts to reduce energy costs in new school buildings have seen the use of tighter construction, sealed windo ws an d heavier insulation. While these construction techniques have helped reduce energy costs, tightly sealed buildings, or envelopes, when combined with increased use of recirculated air, can lead to unhealthy air.

For this reason, the American Society of Heating, Refrigeration and Air Condition now recommends 15 cfm of outdoor air per pu pil, a nd no longer endorses the practice of little or no usage of outdoor air.

It should be kept in mind that a properly designed

xhaust system is essential for avoiding indoor air quality

e problems. Simply put, if room air is not being exhausted in a prescribed fashion, fresh outside air cannot be introduced into the room. Likewise, an excessive amount of outside air will be admitted, wasting energy.

The AAF-HermanNelson Ventimatic sh actuated room exhaust vent, can solve both these problems. The Ventimatic shutter allows the correct amount of outdoor air to be brought into the room while maintaining a slight positive pressure in the room. This slight positive pressure, maintained during normal operation, can also help prevent the infiltra tion of undesirable gases into the classr oom. See “VentiMatic™ Shutter Room Exhaust Ventilation” on page 25.

ing Engineers (ASHRAE)

utter, a gr avity-

Following ASHRAE Control

percentage of outside air. The heating coil capacity controller then modulates to maintain the thermostat setting.

If the room temperature rises above the thermostat setting, th damper opens beyond the minimum position to maintain the thermostat setting.

EXAMPLE: For a 60°F entering air and 70°F room temperature, with 30°F outdoor air temperature, 25% outdoor air will produce the 60°F mixture air temperature. When the outdoor air temperature drops to 10°F, 12.5% outdoor air will produce the 60°F mixture air temperature.

e heating coil is turned off and the outdoor air

mixture temperature

Night Setback

Substantial fuel savings can be realized by operating th e unit ventilator system at a reduced room setting at night and during other unoccupied perio ds, su ch a s we ekend s and holidays. Units with steam or hot-water coils will provide convective heat during the setback period. If the space temperature falls below the setting of the unoccupied thermostat, the unit fans will be brought on to provide additional heat. Units with electric heat coils do not provide convective heat. The electric coil and the unit fans will be brought on to maintain the thermostat setting.

Typical Temperature Control Components

In general, unit ventilators require the following basic DDC electrical components in order to operate on any of the standard unit ventilator ASHRAE cycles of control. The control components listed in this section are for familiarization purposes only and should not be construed as a bill of material.

Cycle II

ASHRAE Cycle II is a very economical sequence of control because only minimum amounts of out door air are heated and free outdoor air—natural cooling—is available to offset the large internal heat gain associated with the dense occupancy of classrooms.

AAF-HermanNelson unit ventilators are normally

rolled according to ASHRAE Control Cycle II.

cont ASHRAE control cycles apply only to heating, heatingand-ventilating and free-cooling operation. (For more information on the ASHRAE Control Cycle II sequence, see Figure 42 on page 36.)

Under ASHRAE Cycle II, the outdoor air damper is

during warmup of the room. As the room

closed temperature approaches the thermostat setting, the outdoor air damper opens to a predetermined minimum

AAF-HermanNelson Model AZ Unit Ventilators 29

Outdoor Air Damper Actuator

This is a modulating device under the control of the room and discharge sensors. It positions the outdoor air damper to admit the amount of outdoor air required at any given point in the control cycle. The room air damper is mechanically linked to the outdoor air damper, which permits the use of a single actuator. Electric actuators should be of the spring-return type so that the out door air damper closes whenever the electric power supply to the unit is interrupted.

Discharge Airstream Sensor

This device overrides the room sensor and modulates the outdoor air damper toward the closed position when the unit discharge air falls to a potentially uncomfortable temperature.

Application Considerations

Temperature Modulation Devices

The temperature of the air entering the room is modulated using one or more of the following devices:

Face and Bypass Damper Control: A modulating

damper actuator, under control of the room sensor, positions a face and bypass damper to control the amount of air that passes through or around the unit coil.

Valve Control : A modulating valve, under control of the

room sensor, regulates the flow of steam,or hot water through the unit coil.

Electric Heat Step Control: A modulating step controller,

under control of the room sensor, steps individual electric heating elements on and off as required. Staging relays are sometimes used in lieu of a step controller.

Note: When unit ventilators containing electric heat are

ordered without controls (controls by others) the contractors and relays used for staging the electric heat are not provided. This is because the number of stages varies based on the type and manufacturer of the control devices. It is not possible to pre-engineer contractors and relays for all of these variables. The control contractor is responsible for making certain that the controls correctly control the unit’s functions.

Room Temperature Sensor

The room temperature sensor is a device that modulates the intensity of a pneumatic or electric signal to the controlled components within the unit to maintain the room sensor’s comfort setting. Room sensors can be mounted on the wall or within the unit.

Additional Components

Additional components may be required depending on the specific application. They include:

Room Temperature Sensor Chamber: When the Room

Temperature Sensor is to be mounted within the unit ventilator rather than on the wall, it is located behind a series of holes in the unit front panel with the sensing element sealed within the room temperature chamber. The room temperature chamber is a standard feature with units furnished with MicroTech II controls.

Low Temperature Protection: A low temperature limit or

freezestat senses the discharge air temperature off the hydronic coil. If the temperature drops below 38°F, the unit ventilator will shut down, closing the outdoor air damper and opening the heating valve.

DX Cooling Control : This sequence switch in the

cooling control circuit energizes the condensing unit contactor on a call for mechanical cooling.

DX Cooling Low Ambient Lockout: This lockout must be

used on DX split systems to lock out the condensing unit when the outdoor air temperature is below 64°F (17.5°C). This device must be integrated into the control system so that the unit has full ventilation cooling capability during the lockout period.

DX Low Temperature Limit : This limit must be used on

DX split system cooling units to de-energize the condensing unit (compressor) when the refrigerant falls below freezing. DX units with MicroTech II controls have a factory-installed sensor on the return bend of the DX coil that provides a sample of the coil’s temperature.

30 McQuay Catalog 1620

Application Considerations

Meeting IBC Seismic Requirements

AAF-HermanNelson unit ventilators can be specified, as follows, to meet International Building Code seismic requirements:

• All components included in these unit ventilators are signed, manufactured and independently tested,

de rated and certified to meet the seismic compliance standards of the International Building Code.

mponents designated for use in systems that are life

• Co

safety

, toxic, high hazard, combustible or flammable meet the on line, anchorage and load path requirements for life safety as defined in IBC sections

1621.1.6, 1621.3.3,1707.7.2. and IBC Commentary, Volume II, section 1621 .1.6, IBC notes pertaining to the release of hazardous material.

• All co

Figure 38. Seismic Installation

mponents used as part of a system ot her than the

ove meet as a minimum, all load path and

ab anchorage standards for components as outlined in IBC section 1621.3.3 & 1707.7.2.

Left End Compartment Area for Securing Unit to Floor

• All completed labeled for field inspection. Seismic Compliance Labels include the manufacturer's identification, designation of certified models, definitive information describing the product's compliance characteristics, and the Independent Certifying Agency's name and report identification.

In addition to all seismic requirements for IBC Certification listed els submittals for these units include:

1 A Certificate of Compliance from the Independent

ifying Agency clearly indicating that components

Cert supplied on this project are included in the component manufacturer's Certificate of Compliance.

2 Clear inst

components that are part of the overall component installation.

component assemblies are c

where in the project specification,

allation instruc

tions including all accessory

learly

Right End Optional Caster

Right End Compartment Area for Securing Unit to Floor

Right End Compressor Compartment

1/4"dia. x 2" x 5/16" Hex Washer Head Concrete Screw – 2

AAF-HermanNelson Model AZ Unit Ventilators 31

Application Considerations

Face & Bypass Temperature Control

Precise Environment Control

Face and bypass damper control units utilize standard

when less heat is required. All air bypasses the coil when “free” cooling or no heating is required.

unit ventilator cycles of temperature control and bring in up to 100% fresh outdoor air for ventilation (free) cooling of the classroom. The bypass damper allows all air to pass through the heating coil for fast warm-up. A portion passes through the coil and a portion bypasses the coil

Figure 39. Face & Bypass Temperature Control

Morning Warm-Up

Figure A shows the face and bypass damper, the room air damper, and the outdoor air damper positioned for “morning warm-up/cooldown.” During the summer the unit is cooling; in winter it is heating. When the room air temperature is above (cooling) or below (heating) the sensor setpoint, the face and bypass damper is open to the coil. At the same time, the outdoor air damper is closed and the room air damper is open. All air handled by the fan passes through the coil for maximum heating or cooling.

Maximum Heat Or Cool, Minimum Outdoor Air

Figure B shows the damper positions as the room temperature approaches the room thermostat setting. The outdoor air damper is open to the minimum setting and the room air damper closes slightly. Unit ventilators normally admit the same minimum percentage of outdoor air during the mechanical cooling cycle as during the heating cycle.

Minimum Outdoor Air, face and bypass Damper Modulation

Figure C shows normal operation. Room temperature is maintained within the operating range. Under these conditions, the outdoor air and room air dampers retain their same positions while the face and bypass damper modulates to provide accurate room tem p er at ur e control. (heating only)

Full Outdoor Air (Free Cooling)

Figure D shows the damper positions for maximum ventilation coo ling. When uncontrolled heat sources tend to overheat a room (such as people, lights or sunlight), the face and bypass damper will bypass 100% of the air around the heat transfer element. The end-of-cycle valve (if furnished) will be closed to the coil. The outdoor air damper will position itself for additional outdoor air, up to 100% of the fan capacity, as required by the room cooling needs. As the outdoor air damper opens, the room air damper closes proportionally.

Side

Coil

Outdoor Air

Outdoor Air Damper Closed

Damper Closed

Side

Outdoor Air Damper

Outdoor Air

Side

Outdoor Air Damper

Outdoor Air

Side

Coil Outdoor Air Damper

Outdoor Air

100% Room Air

Minimum Outdoor Air

Coil

Minimum Outdoor Air

Coil

100% Outdoor Air

Room SideOutdoor

Face & Bypass

Damper

Room Air

Room Air Damper

Damper

Room Air

Room SideOutdoor

Face & Bypass Damper

Room Air Damper

Room Air

Room SideOutdoor

Face & Bypass Damper

Room Air Damper

Room Air

Room SideOutdoor

Face & Bypass Damper

Room Air Damper Closed

32 McQuay Catalog 1620

Application Considerations

Ease Of System Balancing

With face and bypass damper control, the water in the system is constantly circulating, which maintains a desirable head pressure to the pumps. With fluctuating head pressure eliminated, balancing the sys te m ca n enable the correct quantity of water in all circuits.

Two Stage Compressors

Our self-contained units with the two-stage compressor will run on lower fan speeds up to 70% of the time, improving comfort through better humidity control and quieter operation, while minimizing issues with over sizing. The unit is designed to operate in low compression mode while in medium and low fan speed. The reduced cooling capacity in the medium and low fan speed will allow the system to run longer at moderate and low load conditions providing better humidity contro l. When the high capacity is needed the high speed will provide high compression and full capacity cooling.

Reduced Risk Of Coil Freeze

With face and bypass damper control, there is no change in the flow of water through the coil. Coils that have a constant flow of water cannot freeze. On valve control units, water left in the heating coils after the modulating temperature control valve shuts can freeze and rupture the coil.

Additional freeze protection is afforded by AAF-

manNelson’s double-walled cold weather outdoor

Her damper. It has encapsulated insulation and wool mohair end seals to help prevent unwanted cold air from entering the unit.

A low-temperature freezestat, factory installed on all

ronic units, significantly reduces the chance of coil

hyd freeze-up. Its wave-like configuration senses multiple locations by blanketing the leaving air side of the coil to react to freezing conditions.

AAF-HermanNelson Model AZ Unit Ventilators 33

Application Considerations

Modulating Valve Temperature Control

Modulating Valve Control With Hot Water Or Steam

control valve and all air handled by the unit will pass through the heating coil at all times.

The description of unit operation given for dampercontrolled units is correct for valve-controlled units except that references to face and bypass dampers and end-of-cycle valves should be disregarded. The capacity of the heating coil will be regulated by a modulating

Hot Water Reset

Hot water system controls should include a provision for resetting the temperature of the supply hot water in relation to the temperature of the out door air. A hot water temperature of 100°-110°F, is suggested when the

Figure 40. Modulating V al v e Temperature Control

Morning Warm-Up

Figure A shows the modulating valve allowing full flow through the coil and the room air damper and outd oor air damper positioned fo r morning warm-up. In the summer, this is full cooling; in the winter, it is full heating. When the room temperature is below the setpoin t (heating), the valve opens for full flow through the coil. All air is directed through the coil(s).

Minimum Heating

Figure B shows the outdoor air damper moved to its minimum position. The modulating valve is still allowing full flow through the coil. Unit ventilators normally admit the same minimum percentage of outdoor air during the heating cycle as during the mechanical cooling cycle. All the air is directed through the coils.

Minimum Outdoor Air

Figure C shows normal operation. Room temperature is maintained by modulating the flow through the coil (heating only). The outdoor and room air dampers maintain the same positions and all air is directed through the coils.

Side

100% Room Air

Coil

Outdoor Air Damper Closed

Side

Mixed Air

Coil

Outdoor Air

Side

Mixed Air

Room SideOutdoor

Room Air

Room SideOutdoor

Room Air

Room SideOutdoor

Outdoor Air

Room Air

Full Outdoor Air (Free Cooling)

Figure D shows the modulating valve closed, allowing no flow through

Side

Room SideOutdoor

the coil. The outdoor damper is fully open and the room air dampe r is closed. The sensor setting dictates when the out door damper needs to begin closing. When the minimum outdoor damper position is reached, the valve needs to modulate towards the full open position. All the air is directed through the coils. (Care must be taken to ensure coils are not exposed to freezing air conditions when the modulating valve is shut or

100% Outdoor Air

Outdoor Air

Coil

no water is flowing through coils. See “Freeze Protection” on page 35.)

34 McQuay Catalog 1620

Application Considerations

outdoor air temperature is 60°F. The upper limit of the hot water temperature will be dictated by the winter design conditions.

The need for hot water reset controls applications involving unit ventilators with face and bypass control. Valve control performance will be improved as well. When the supply water temperature is far in excess of that required to offset the heat loss of the space, the smooth modulating effect of the control valve is lost. The control valve will cycle between slightly open and fully closed. The effect of heat conduction through a closed valve will also be reduced when hot water reset is used.

is not limited

Freeze Protection

System freeze protection is an important consideration on units utilizing hydronic coils. On valve-controlled units, water left in the heating coils and exposed to freezing outdoor air after the modulating valve shuts can freeze and rupture the coil. Flowing water will not freeze. In addition, it is very important to correctly size the modulating control valve and control the supply water temperature to provide constant water flow. If this situation cannot be guaranteed, an antifreeze solution must be employed to reduce the possibility of coil freeze.

ventilation requirements. Tuned internal flow and a balanced header design, together with additional surface area in the air stream, increase heat transfer to satisfy the increased need for heat.

A manual air vent is located on the top of the coil header

hydr

of all floor be purged from the coil during field start-up or for maintena

A manual drain plug (Figure 41) is provided at th e bottom of the coil header for coil drainage. Some competitors

y no

Figure 41. Manual Air Vent & Drain Plug

t provide for drainage of coils.

onic coils. (Figure 41). This allows air to

nce.

Coil Selection

An extensive choice of coil offerings means that, with AAF-HermanNelson unit ventilators, room conditions can be met using almost any cooling or heating source . All coils are located safely beneath the fans and are designed for draw-thru air flow. All coils have their own unshared fin surfaces (some manufacturers use a continuous fin surface, sacrificing proper heat tr an sfe r) . The result is maximum efficiency of heat transfer, which promotes comfort and reduces operating costs.

An air break between coils in all AAF-HermanNelson

its is used to enhance decoupling of heat transfer

u surfaces—providing full capacity output, comfort and reduced operating costs.

All water, steam and direct expansion (DX) coils are

tructed of aluminum fins with a formed, integral

con spacing collar. The fins are mechanically bonded to the seamless copper tubes by expansion of the tubes after assembly. Fins are rippled or embossed for strength and increased heat transfer surface.

High-Quality Water Coils

AAF-HermanNelson coils rely on advanced heat transfer to provide extra heating capacity for today’s increased

Long Lasting Electric Heating Coils

With our draw-thru design, electric coils are directly exposed to the air stream. They come with a built-in switch to de-energize the coil when the center front panel is removed. A unit-mounted disconnect switch is included. A continuous electric sensory element for high temperature is not required because the air is drawn smoothly and evenly across the coils, prolonging life. (Blow-thru designs use cal rods inserted into the tube of a fin tube coil that results in reduced heat transfer. The constant movement of the electric heating cal rod with in the tube shortens life.)

Even Distribution Steam Coils With V acuum Breakers

Steam distribution coils provide even distribution of steam and even discharge air temperatures. A vacuum breaker relieves the vacuum in the steam coil to allow drainage of condensate. This eliminates water hammer and greatly reduces the possibility of coil freeze-up.

AAF-HermanNelson Model AZ Unit Ventilators 35

Application Considerations

ASHRAE Cycle II

We strongly recommend that ASHRAE Cycle II be implemented with all unit ventilators using controls by others. ASHRAE Cycle II is a very economical sequence since only the minimum amount of outside air is conditioned and free natural cooling is available. See Figure 42:“ASHRAE Cycle II Operation” on page 36.

During warm-up (any classroom temperature 3°F or

below heating setpoint), the outdoor air damper is

mo closed and the unit conditions only room air. As room temperature approaches the heating setpoint the out door air damper opens to a position that permits a predetermined minimum amount of outside air to be drawn in. Unit capacity is then controlled as needed to maintain room setpoints. If room temperature rises above room cooling setpoint, and the outside air is adequate for economizer cooling, then the outdoor air damper may open above the minimum positio n to provide economizer cooling.

ASHRAE Cycle II requires that a minimum of three

ature measurements be made:

per

tem

Figure 42. ASHRAE Cycle II Operation

ssroom temperature.

1 Cla 2 Unit discharge air temperature. 3 Outdoor air temperature.

Add

itionally, the control sequence should incorporate a

Discha

rge Air Low Limit function which requires a discharge air temperature sensor and can override classroom temperature control in order to maintain a discharge air temperature setpoint of 55°F (ventilation cooling 45°F mechanical cooling).

When the discharge air temperature drops below 55°F,

harge-air low-limit function will disable cooling (if

the dis enabled) and modulate the unit’s heating capability as needed to maintain the 55°F discharge-air setpoint regardless of room temperature.

If the unit’s heating capability

reaches

100%, then the discharge air low-limit function will modulate the outdoor air damper toward closed to maintain the 55°F discharge air setpoint. Outdoor air temperature is used to determine when to use economizer as a first stage of cooling, and when to use mechanical or hydronic cooling as the first stage of cooling.

Typical Outdoor Air Damper Operation

A Outdoor air damper closed. B Outdoor air damper at minimum position. C Economizer function is increasing the outdoor air

amper position.

Note: If outdoor air temperature is not adequate for free cooling,

secondary mechanical cooling can be used in place of economizer cooling. A low discharge air function is used to help maintain comfort and provide additional equipment protection by preventing the discharge air from falling too low (typically 55°F), and may force the outdoor air damper toward closed to maintain the discharge air temperature regardless of room temperature.)

D Damper is at full open.

Typical Heating Operation

E Heating capa

bility is closed (or off).

F Heating begins to modulate (or on). G Heating capa

Typical Mechanical Cooling Operation

bility has reached 100%.

H M echanical cooling (DX) is closed (or off).

Mechanical cooling (DX) has reached 100%.

End-Of-Cycle (EOC) Valve Operation

The intended purpose of an EOC valve is to reduce the chances of conductive radiant overheating which can

36 McQuay Catalog 1620

occur when the face and bypass damper is in the full bypass position (i.e., no heating).

A heating EOC valve must be used on units with DX cooling coup

led with steam or hot water heat and face

Application Considerations

and bypass damper temperature control. It is optiona l for the remaining models. However, it is strongly recommended that heating or heat/cool EOC valves be used on all face and bypass units with heating capability to prevent overheating.

Heating EOC Valve

For steam or hot water heat only with face and bypass damper control; steam or hot water heat with face and bypass damper control coupled DX cooling:

The heating EOC valve should be a normally open,

ing return (open), two position valve. In addition:

spr

1 Heating Operation: Wh

2°F or more below the heating setpoint, the EOC valve should open and remain open until the room temperature becomes equal to the heating setpoint or higher.

2 Operation Due To Outside Air Temperature: If

outside air temperature is equal to or less than 35°F, the EOC valve should open, the EOC should then remain open until the outdoor air temp erature reaches 37°F. or higher.

en the room temperature is

the

Water Coil Low Air Temperature Limit (Freezestat) Operation

The Water Coil Low Air Temperature Limit, or freezestat, function is intended to help protect the water coil from extremely low air conditions. All units with hydronic coils ship with a freezestat. The freezestat has a cut-out temperature setting of no less than 38±3°F and a cut-in temperature setting of approximately 48±3°F. The freezestat is intended as a backup in case the normal operating controls fail to protect the equipment. It is used in the following manner:

DX Cooling With Hot Water Heat & Face and Bypass Control:

of the hot water heating coil. When the freezestat cuts out due to low temperatures, the following should occur:

• T

• The

maintain space temperature.

When the freezestat cuts in after cut-out, normal op

The freezestat is secured to the leaving air face

he compressor is de-energized. he outdoor air damper is closed.

heating EOC valve is forced to full open. face and bypass damper modulates as needed to

eration may return.

Valve Control Applications

System freeze protection must be considered on valve controlled units utilizing hydronic coils. Non-flowing water in heating coils that are exposed to freezing outdoo r air can freeze and rupture the coil (after the modulating valve shuts). The modulating control valve must be

correctly sized and the supply water temperatu r e controlled to ensure constant water flow. If this cannot be guaranteed, use an antifreeze solution to eliminate the possibility of coil freeze.

DX Cooling With Hot Water Heat & Valve Control: The

freezestat is secured to the leaving air face of the hot water heating coil. When the freezestat cuts out due to low temperatures, the following should occur:

he compressor (condensing unit) is de-energized.

• T

he outdoor air damper is closed.

• T

he unit fan is de-energized.

• T

he heating valve is forced to full open.

• Wh

en the freezestat cuts in after cut-out, normal

operation may return.

Unit Installation

Carefully arrange the location and installation of each model AZ unit to provide convenient service access for maintenance and, if necessary, removal of the unit. The installation consists of four basic elements in the following order:

uver

1 Lo 2 Galvanized W

rizontal Air Splitters by others (if required)

3 Ho 4 AZ Self-cont

The louver brings in outdoor air for the condense r fan section an providing a path for heated condenser air to exit.

The Wall Sleeve secures the unit, provides a watertight

d air tight seal to the building and brings in electrical

an and control wiring (if required). It contains the unit main power disconnect switch which is located in the wall sleeve junction box. All field electrical connections are made inside this box.

Horizontal Air Splitters provide proper air paths and min

The AZ self-contained unit ventilator provides comfort coo designed to be installed into or up against an exterior wall. The louver, air splitters (if required) and wall sleeve are installed before the AZ unit is install ed.

On many jobs, the louver and wall sleeve are shipped

ead of the unit itself. Installation instructions for these

ah components are shipped with the individual components included in this publication.

The following are general instr applications. In all cases, good engineering practices and local codes must be followed.

d ventilation air to the classroom while

imize air recirculation.

ling and heating for the space. The Model AZ unit is

all Sleeve

ained Unit Ventilator

uctions for suggested

AAF-HermanNelson Model AZ Unit Ventilators 37

Application Considerations

(

)

ete

(

her

)

Per

eve

65/

(

422mm

)

(

76m

(

)

ver

(

)

Per

lLi

(

her

)

Wal

eve

65/

(

422mm

)

(

76m

)3(

76m

)

ete

5/8

(

)

(

)

(

76m

)3(

)

(

Per

Figure 43. Typical Self-Contained Unit Ventilator Installation

Internal Column for Wall Bracing and Anchoring (by others)

Optional Louver Flange

Seal Horizontal Air Splitters to Building at Both Ends

Drain Holes in Splitters (by others)

Louver–Bird Screen

3. Horizontal Air Splitters

(Field Made to Job Conditions by Others) Pitch Down Toward Louver

Louver Blade

Bottom Flange

Weep Holes

Condenser Discharge

Condenser Supply Air

Textured Charcoal Bronze Unit Projection Top (Except Fully Recessed Wall Sleeve)

Conduit (by others)

Wall Sleeve Junction Box

Outside Ai

1. Louver

Must be sealed watertight at top and both ends

Galvanized Condenser (Outdoor) Section

Textured, Scuff Resistant, Charcoal Bronze, Environmentally Friendly Thermosetting Urethane Powder Paint Top

4. AZ Self-Contained Unit Ventilator

Caster on Outdoor Section

Wall Sleeve Threaded Studs for Fastening to Unit (Ships on Wall Sleeve)

2. Galvanized Wall Sleeve

Sealed Cement Mortar, Pitched Away from Unit Toward Louver

Caster Kit for Indoor Section (Optional)

6" End Panel (Optional)

Wall Louvers

The outdoor air wall louver is usually set directly back of the unit ventilator. The position of the wall louver is determined in general by the building construction. The top of the lower channel of the louver frame should be at

Figure 44.

Louver

(Note 2)

28"

(1m)

(711mm)

Caulk

Perimeter

Notes:

1 Horizontal splitter (by others) must be installed whenever there is any

space between the wall sleeve and the louver. It is also necessary to seal the ends of the wall opening.

2 The top and two sides of the louver must be caulked watertight. Do not

ca details.

3 Louvers may be recessed a maximum of 2" (51mm) from the exterior face

the wall.

Wall Penetration Detail

See ote

Note 1

Sleeve

au im

Wall

Steel Lintel

(By Others)

16 5/8"

(422mm)

(76mm)

3" (76mm)

Floor Floor

Full Recess Partial Recess No Recess

k bottom edge of louver. Refer to installation instructions in IM 1065 for

Louver

(Note 2)

28"

(1mm

(711mm)

Caulk

Perimeter

least 1/2" below the level of the inlet to the unit ventilator. However, if a high int ake ope ning is necessary, the top of this opening should be not more than 28" above the surface upon which the unit ventilator will set.

Louver

Steel Lintel

S (By Others)

16 5/8"

(422mm)

Wall

Sleeve

(76mm)

FLOOR

(INCLUDING CARPET)

4 Drain must be flush with floor to allow unit installation and removal. Unit

ain

5 A field supplied air seal should be applied to the exterior perimeter of the

wall

3" (76mm)

tube is 7/8" (22mm) O.D. copper.

sleeve when unit is installed with no recess.

(Note 2)

28"

(

(711mm)

Caulk

Perimeter

28"

(711mm)

16 5/8"

eve

(422mm)

(76mm)

Wall

Sleeve

3" (76mm)

38 McQuay Catalog 1620

Application Considerations

Lintels

When brickwork is built up to the top of the intake, lintels must be used above the wall louvers. While the wall is still wet, finish the brick on the top, bottom and both sides of the intake opening with 1/2" cement mortar. With the standard location of the wall louver, the bottom of the intake opening must slope from the louver frame up

Figure 45.

Unit Cross Section

28" Type 21-7/8" Type

*Wall Sleeve Unit Depth

/8"

(289mm)

/4"

/8"

/8" (422mm)

28" (711mm)

30"

(762mm)

28"

(711mm)

2 Louver

/2"

(See Note)

Wall Thickness

(25.4mm)

Splitters

(by others)

5/8"

(16mm)

(286mm)

(181mm)

3" (76mm)

(25.4mm)

toward the intake opening to a point 1" above the finished base of the unit.

If a metal sleeve connection is to be used between the

ventilator and the wall louv

unit

er, this sleeve must be installed after the unit ventilator is set, making a weathertight connection to the unit ventilator cabinet. Turn the sleeve over the edge of the louver frame by proper peening before the louver is finally installed.

/4"

(133mm)

*Wall Sleeve Unit Depth

/4"

/8"

/8" (422mm)

28" (711mm)

30"

(762mm)

28"

(711mm)

2 Louver

/2"

(See Note)

Wall Thickness

(25.4mm)

Splitters

(by others)

5/8"

(16mm)

(286mm)

(181mm)

3" (76mm)

(25.4mm)

(76mm)

*Wall Sleeve Unit Depth

/8" (422mm)

28"

30"

(762mm)

28" (711mm)

*Shading indicates portion of unit wall sleeve recessed into wall opening

(711mm)

2 Louver

(See Note)

(25.4mm)

Splitters

(by others)

5/8"

(16mm)

/2"

Wall Thickness

/4"

(286mm)

/8"

(181mm)

3" (76mm)

(25.4mm)

Unit Depth

/8" (422mm)

28" (711mm)

30"

(762mm)

28"

(711mm)

2 Louver

/2"

(See Note)

19-5/8" Type 16-5/8" Type

Wall Thickness

/4"

(286mm)

(25.4mm)

Splitters

(by others)

5/8"

(16mm)

/8"

(181mm)

3" (76mm)

(25.4mm)

Note: Horizontal splitter (by others) must be installed whenever there is any space between the wall sleeve and the louver. It is also

sary to seal the ends of the wall opening. See table below for splitter length versus wall thickness.

neces

Table 1: Splitter Length and Wall Thickness

Unit Projection

28" Type 21-7/8" Type 19-5/8" Type 16-5/8" Type

2-1/2 4 6 8 8-5/8 10 10-7/8 12 13-7/8 14 16 18 24

0" 1-1/2" 3-1/2" 5-1/2" 6-1/8" 7-1/2" 8-3/8" 9-1/2"

0" 1-3/8" 2-1/4" 3-3 /8"

Wall Thickness

0" 1-1/8" 3" 3-1/8"

0" 1/8" 2-1/8" 4-1/8" 10-1/8"

AAF-HermanNelson Model AZ Unit Ventilators 39

Application Considerations

Interior Considerations

The interior wall surface behind the unit ventilator must be smooth and level. A wall that is slightly out of plumb can cause major problems with outside air leakage into the room and unit. This could cause draft s and potentially freeze coils.

Be certain that no gap is left between the unit and th e

side air louver opening. Otherwise, outside air can

ou leak into the room.

A rubberized, self-adhering membrane around the

tside air opening can be used to seal any air or water

o leaks that might result from construction. Provide a seal under the unit to prevent air infiltration. In addition, seal the unit top and side perimeters to prevent unnecessary air infiltration due to uneven walls.

Indoor Air Exhaust Considerations

All outdoor air introduced by the unit ventilator must leave the room in some way. In some states, exhaust

Wall Sleeve Arrangements

vents are required by law. In states where vents are not required by law, a decision must be made about how best to handle this problem.

The venting system chosen should have the ability to exhaust

varying amounts of air equal to the amount of outside air introduced by the unit ventilator. A constant volume system, such as a powered exhaust, is unable to respond to changing conditions. It will either exhaust too much air, resulting in a negative pressure, which draws in more outdoor air than desired. Or, it will exhaust too little air, resulting in increased positive pressure, which restricts the amount of outside air being brought into the room.

The AAF-HermanNelson Ventimatic shutter eco

nomical solution to the problem. See “VentiMatic™

is a more

Shutter Room Exhaust Ventilation” on page 25 for information on this system and its proper installation.

Figure 46.

By Others. Seal Horizontal Air Splitters to building at both ends.

IMPORTANT NOTE: By Others: Attach Horizontal Air Splitters to Wall Sleeve

Splitters as shown. Splitters to have 1" dia. drain hole approx. 6" from each end.

Recessed Wall Sleeve With Horizontal Air Splitters

By Others. Wall Sleeve must be sealed watertight at top and both ends at location shown.

By Others. Seal both ends of opening between Wall Sleeve and Louver.

Wall Sleeve Splitter(s) (See Caution Above)

D Seal

By Others. Wall Sleeve must be sealed watertight at bottom at location shown. Refer to cross section detail of bottom of Wall Sleeve and Louver.

Seal Horizontal Air Splitter(s) to Louver. (By Others)

By Others. Louver must be sealed watertight at top and both ends.

/16" Under Intake must be free for water run-off. Intake must

stand on embossed feet located on bottom.

By Others. Building must be sealed between Wall Sleeve and under Louver for water run-off. Pitch toward Louver.

Condenser discharge

Condenser inlet

Outdoor air inlet

40 McQuay Catalog 1620

Application Considerations

Figure 47.

IMPORTANT NOTE : By Others: Attach Horizontal Air

Splitters to Wall Sleeve Splitters as shown. Splitters to have 1" dia. drain hole approx. 6" from each end.

Figure 48.

By Others. Wall Sleeve must be sealed watertight at top and both ends at location shown.

Nonrecessed Wall Sleeve With Horizontal Air Splitters

Recessed Wall Sleeve Without Horizontal Air Splitters

IMPORTANT NOTE: By Others. Seal Louver to Wall Sleeve at top and bottom Wall Sleeve Splitters, and ends.

By Others. Louver must be sealed watertight at top and both ends.

Wall Sleeve Splitter(s)

D Seal

By Others. Seal Horizontal Air Splitters to building at both ends.

By Others. Wall Sleeve must be sealed watertight at bottom at location shown. Refer to cross section detail of bottom of Wall Sleeve and Louver.

Figure 49.

Nonrecessed Wall Sleeve Without Horizontal Air Splitters

IMPORTANT NOTE: By Others. Seal Louver to Wall Sleeve at top and bottom Wall Sleeve Splitters, and ends.

By Others. Wall Sleeve must be sealed watertight at top and both ends at location shown.

Wall Sleeve Splitter(s)

D Seal

By Others. Seal Horizontal Air Splitters to building at both ends.

By Others. Wall Sleeve must be sealed watertight at bottom at location shown. Refer to cross section detail of bottom of Wall Sleeve and Louver.

/16" Under Intake must be free for water run-off. Intake must

stand on embossed feet located on bottom.

By Others. Building must be sealed between Wall Sleeve and under Louver for water run-off. Pitch toward Louver.

By Others. Louver must be sealed watertight at top and both ends.

By Others. Building must be sealed between Wall Sleeve and under Louver for water run-off. Pitch toward Louver.

/16" Under Intake must be free for water run-off. Intake must

stand on embossed feet located on bottom.

AAF-HermanNelson Model AZ Unit Ventilators 41

Unit Selection

Quick Selection Procedure

The following procedure will provide you with a rough

Table 2: Hot Water Heating Capacity Btuh

determination of unit capacity for cooling and/or heating based on the number of coil rows. Use capacity tables for final selection. Consult your local AAF-HermanNelson representative for details on the computer selection programs McQuay International provides for this purpose

Table 3: Standard Cooling at High Indoor Fan Speed

Conditions; Indoor 80ºDB / 67ºWB, Outdoor 95ºDB / 75ºWB

Nominal Airflow High Indoor

fan speed

Unit Size L/S Btuh Watts Btuh Watts EER Watts

024 472 22,100 6,478 15,500 4,543 9.7 2,276 036 590 36,800 10,786 23,800 6,976 9.5 3,888 044 708 44,000 12,896 31,500 9,233 9.4 4,700 054 708 52,100 15,271 35,500 10,405 9.3 5,600

Table 4: Partial Load Cooling at Medium Indoor Fan Speed

Nominal Airflow Medium

Indoor fan speed

Unit Size L/S Btuh Watt s Btuh Watts EER Watts

024 354 18,000 5,276 12,200 3,576 12.6 1,423 036 472 28,000 8,207 19,000 5,569 12.4 2,259 044 542 36,300 10,640 24,900 7,298 11.8 3,060 054 542 42,700 12,515 27,500 8,060 11.8 3,600

Total Cooling Capacity Sensible Cooling Capacity Efficiency Power

Conditions; Indoor 80ºDB / 67ºWB, Outdoor 82ºDB / 65ºWB

Total Cooling Capacity Sensible Cooling Capacity Efficiency Power

Rows 024 036 044, 054

1 49,500 57,000 66,000 2 62,000 74,100 97,200 3 72,000 84,500 97,500 4 81,000 95,000 110,000

60°F Entering Air Temperature; 160°F Entering

Water Temperature;

6 Gpm Water Flow

42 McQuay Catalog 1620

Unit Selection

Selection Procedure

Step 1: Determine Design Conditions

Determine design indoor and outdoor a ir temperatur es in accordance with established engineering practices, as outlined in the ASHRAE Guide or other authoritative source. Indoor temperatures of 80°F dry bulb, 67°F wet bulb for summer and 70°F dry bulb for winter usually are acceptable for design or peak load conditions, even though the expected operating conditions of the system may be somewhat different.

Step 2: Determine Heating and Cooling Loads

Calculate design winter heating losses and summer cooling loads in accordance with the procedures outlined by the ASHRAE Guide or other authoritative source. Perhaps the greatest consideration in calculating design loads is solar heat gain. August solar heat values might be used for summer cooling loads, but should not be used for ventilation air or “natural cooling” capacity calculations; since these cooling loads reach their maximum in the spring and autumn months. The na tu ra l cooling capacity is usually calculated for 55° or 60°F outdoor air temperature.

Step 3: Determine Air Quantity Required

Air quantity for heating applications is determined from circulation of a definite number of room air volumes per hour. Table 5 gives the recommended number of room air changes per hour.

Table 5: Recommende d Ro om Air Changes Per Hour

Type of Space

Classrooms, Offices 6 to 9 Laboratories, Shops 6 to 8

Cafeterias & Kitchens 4-1/2 to 7

For rooms facing east, south or west, the higher values shown in the table should be used so adequate ventilation cooling will be available to prevent overheating during mild sunny weather. The following equation is helpful to determine the CFM air delivery for any given rate of circulation:

Equation 6: CFM For Given Rate Of Circulation

Room Volume (cu ft) Room Changes per Hour×

------------------------------------------------------------------------------------------------------------------- - CFM=

In mechanical cooling applications, the total air quantity may be determined or verified by use of the sensib le cooling load equation:

Recommended number of

room air changes per Hour

Equation 7: CFM Based On Sensible Cooling Load

CFM

Q sensible (space)

------------------------------------------- -=

1.086xTD

Q sensible is the maximum sensible room load and T.D. is the temperature difference between the room design dry bulb temperature and the final or leaving-air dry bulb temperature. For these calculations, a T.D. of 20°F is usually assumed to be desirable to avoid delivering air too cold for comfort. This figure may be varied o ne or two degrees for reasons of practicality.

Note: The sensible load used in the preceding equation is the

space load and excludes the ventilation load.

Most areas have ventilation codes which govern the amount of ventilation air required for scho ol a pplica tio ns. For other than school applications or areas not having codes, the ASHRAE Guide may be used for authoritative recommendations and discussion of the relation between odor control and outdoor air quantities.

The minimum outdoor air quantity recommended by ASHRAE is 15 CFM per

person. L

ower percent minimum outdoor air settings are more economical. In the interest of economy, it may be desirable to use lower percent minimums if there are no ventilation codes.

Step 4: Select Unit Size

The unit should be selected to meet or exceed the CFM delivery requirement previously determined. All model types are available with nominal capacities of 1000, 1 250 and 1500 CFM. Unit sizes 024, 036, 044, and 054.

Heating Capacity

Unit heating capacity should be selected to equal or slightly exceed the computed room heat loss. For units installed for 100% recirculation, it is good practice to increase the heating capacity by 15% to aid in quick room warm-up. This allowance is unnecessary for units delivering a minimum outdoor air of 20% or more, since the outdoor air damper remains closed until the room is up to temperature. The heat normally expended in heating the minimum-percent outdoor air up to room temperature is available for quick warm-up purposes.

The heating required to warm the outdoor ventilating air up to room temperature must also be calculated. The Total Capacity should be used in sizing, piping, boilers, etc.

Cooling Capacity

Unit cooling capacity should be selected to equal or slightly exceed the sum of computed room sensible and

AAF-HermanNelson Model AZ Unit Ventilators 43

Unit Selection

latent heat gains (Room Total Cap acity). When operatin g on the mechanical cooling cycle, the control system introduces a constant amount of outdoor air for ventilation. The latent and sensible heat gain from this outdoor ventilation air must be added to the room total cooling load before choosing the proper capacity unit.

Step 5: Freeze Protection

Constant pump operation is required whenever the outdoor air temperature is below 35°F. This will assist

in providing protection against freeze up of the system water piping and coils. To reduce the possibility of water coil freeze up on valve-controlled units, the valve must be selected properly to provide adequate wate r flow. See “Modulating Valve Sizing & Piping” on page 51. One of the steps below should be followed.

Hot Water

Carry out one of the following steps to help protect against freezing:

• Use antifreeze in the system.

• Open the hot water coil valve and close the outdoor air

mper whenever a freezing condition is sensed at the

da coil.

Step 6: Units With Antifreeze

If ethylene glycol or propylene glycol is used, its effect upon heating capacities and its effect on water pressure drops through the coil and piping system must be considered, as follows:

1 Divide the

applicable capacity correction factor shown in Tables

heating loads determined in S te p 2 by the

6 and 7 below to arrive at the calculated unit capacity required to take care of the capacity reduction caused by the glycol solution

Table 6: Capacity Correction Fa c tors for Ethylene Glycol

Ethylene Glycol% Weight 20% 30% 40%

Hot Water 0.94 0.90 0.84

Table 7: Capacity Correction Factors for Propylene Glycol

Propylene Glycol% Weight 20% 30% 40%

Hot Water 0.98 0.96 0.92

2 Determine the GPM required by entering the

appropriate hot water capacity chart using the calculated unit capacity.

3 Determine the water pressure drop by multiplying the

pressure drop for the GPM determined above

water by the applicable pressure drop correction factor shown in Tables 8 and 9 below

Table 8: Pressure Drop Correction Factors For Ethylene

Glycol

Ethylene Glycol% Weight 20% 30% 40%

Hot Water 1.08 1.11 1.19

Table 9: Pressure Drop Correction Factors For Propylene

Glycol

Propylene Glycol% Weight 20% 30% 40%

Hot Water 1.07 1.11 1.15

44 McQuay Catalog 1620

Unit Selection

Hot Water Heating Selection

For proper temperature control, do not oversize the heating coil. Select the hot water coil that just slightly exceeds the required heating capacity. Hot water coils are offered in two capacities. The low-capacity (65) coil and the high-capacity (66) coil can be used as heating only or in conjunction with direct-expansion cooling coil.

Quick Selection Method Using MBH/∆T

Once the unit size has been selected, the MBH/∆T factor can be utilized to quickly and accurately determine coil size and minimum GPM, where:

ntering Water Temp - Entering Air Temp

∆T = E Fo

r example, assume an entering water temperature of

F, an entering air temperature of 55°F and a total

180° heating load of 75 MBH. Then,

Figure 50. 1-Row Hot Water Coil

0.8

0.7

0.6

MBH/d

0.5

044, 054

1500SCFM

= 180 - 55 = 125

∆T an

MBH/∆T = 75/1

25 = 0.6

Assume we want to size for the 036 unit determined in

coil selection example previously given for cooling.

the Referring to Figures 50 and 51:

1 Enter each chart at MBH/∆T

= 0.6.

2 Move horizontally to the right to intersect the unit 036,

50 scfm curve.

3 Project downward for

GPM requirement.

It is quickly seen that the 1-row coil (Figure 50) does not meet the heating load. The 2-row coil (Figure 51) can meet the requirement with 3.4 GPM.

036

1250SCFM

024

1000SCFM

0.4

0.3 2345678910

Figure 51. 2-Row Hot Water Coil (Parallel Flow)

1.1

0.9

0.8

MBH/dT

0.7

0.6

0.5

0.4 234567 8910

044, 054

1500 SC FM

GPM

036

1250 SC FM

024

1000 SC FM

AAF-HermanNelson Model AZ Unit Ventilators 45

Unit Selection

Steam Heating Selection

The maximum allowable steam pressure, especially in public buildings, is often fixed by state or local boiler codes. Steam Capacity in Table 10 is based on steam supply pressure of 2 PSI gauge and steam temperature

218.5°F.

o To determine total capacity for

conditions other than

capacity given by the proper constant from the Steam

city Correction Factor in Table 11.

Capa Maximum steam pressure is 6

PSIG at coil inlet.

Traps are by others. Either float an d thermostatic tr aps or thermo

static traps may be used.

shown in the Steam Capacity Table 10, multiply the total

LAT, db

Entering Air Temperature °F

MBH

LAT, db

MBH

LAT, db

MBH

LAT, db

MBH

LAT, db

MBH

LAT, db

MBH

Table 10: Steam Heating Capacities - 2# Steam Coils

-20 -10 0 10 20 30 40 50 60 70

Unit

Airflow SCFM

MBH

Coil Capacity

Std 1000 82.1 55.8 78.7 62.6 75.2 69.3 71.6 76.0 68.0 82.7 65.6 90.5 61.8 97.0 58.0 103.5 54.1 109.9 50.4 116.5

024

High 1000 98.3 70.6 94.1 76.8 89.9 82.9 85.6 89.0 81.3 95.0 77.0 101.0 72.3 106.7 67.7 112.4 63.0 118.1 58.4 123.9

Std 1250 97.0 51.6 93.0 58.6 89.0 65.7 85.0 72.7 80.9 79.7 76.7 86.6 72.3 93.3 67.9 100.1 63.5 106.9 59.9 114.2

036

High 1250 122.6 70.4 117.6 76.7 1 12.5 83.0 107.3 89.2 102.1 95.3 96.8 101.4 91.2 107.3 85.6 113.2 80.0 119.0 74.4 124.9

Std 1500 121.3 54.6 116.5 61.6 111.5 68.5 106.5 75.5 101.4 82.3 96.3 89.2 90.8 95.8 85.5 102.5 80.0 109.2 75.6 116.5

044 054

High 1500 140.0 66.0 134.3 72.5 128.5 79.0 123.6 86.0 117.7 92.4 111.8 98.7 105.5 104.8 99.2 111.0 92.8 117.1 86.6 123.2

Data based on 2psig steam pressure @10°F superheat steam vapor.

LAT, db

MBH

LAT, db

MBH

Table 11: Steam Capacity Correction Factors

Steam Pressure

PSIG

0 0.97 0.97 0.97 0.96 0.97 0.97 0.97 0.96 0.96 0.96 2 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 5 1.02 1.03 1.03 1.03 1.04 1.05 1.05 1.05 1.05 1.05

-20 -10 0 10 20 30 40 50 60 70

Entering Air Temperature Mixture, °F

LAT, db

MBH

LAT, db

Engineering Data

Table 12: Electrical Data – Size 024 Models AZQ and AZU

Voltage

208/60/1

230/60/1

208/60/3

230/60/3

460/60/3

† Electric heat options are without compressor and outdoor fan

FLA = Full Load Amps RLA = Rated Load Amps LRA = Locked Rotor Amps MCA = Minimum Circuit Ampacity

Vol tage Range Room Fan

Min Max RLA LRA Heat Type Heater kW Heater Amps MCA Maximum Fuse

197 228 2.7 2.9 11.4 52.0

207 253 2.7 2.9 11.4 52.0

197 228 2.7 2.9 7.9 59.0

207 253 2.7 2.9 7.9 59.0

414 506 2.7 1.2 3.9 29.7

46 McQuay Catalog 1620

FLA

Outdoor Fan

FLA

Compressor Heating Options Power Supply

None, Hot Water, Steam -- -- 19.9 30

†Electric Heat

None, Hot Water, Steam -- -- 19.9 30

†Electric Heat

None, Hot Water, Steam -- -- 15.5 20

†Electric Heat

None, Hot Water, Steam -- -- 15.5 20

†Electric Heat

None, Hot Water, Steam -- -- 8.8 15

†Electric Heat

Low (3-elem.) 8.0 38.5 51.5 60 High (6-elem.) 16.0 76.9 99.5 100

Low (3-elem.) 7.7 33.3 45.0 45 High (6-elem.) 15.3 66.7 86.7 90

Low (3-elem.) 8.0 22.2 31.1 35 High (6-elem.) 16.0 44.4 58.9 60

Low (3-elem.) 7.7 19.2 27.4 30 High (6-elem.) 15.3 38.5 51.5 50

Low (3-elem.) 7.7 9.6 15.4 20 High (6-elem.) 15.3 19.2 27.4 25

Unit Selection

Table 13: Electrical Data – Size 036 Models AZQ and AZU

Voltage

208/60/1

230/60/1

208/60/3

230/60/3

460/60/3

Vol tage Range Room Fan

Min Max RLA LRA Heat Type Heater kW Heater Amps MCA Maximum Fuse

197 228 2.7 2.9 18.6 96.0

207 253 2.7 2.9 18.6 96.0

197 228 2.7 2.9 15.0 88.0

207 253 2.7 2.9 15.0 88.0

414 506 2.7 1.2 6.8 44.0

† Electric heat options are without compressor and outdoor fan

FLA = Full Load Amps RLA = Rated Load Amps LRA = Locked Rotor Amps MCA = Minimum Circuit Ampacity

Table 14: Electrical Data – Size 044 Models AZQ and AZU

Voltage

208/60/1

230/60/1

208/60/3

230/60/3

460/60/3

† Electric heat options are without compressor and outdoor fan

FLA = Full Load Amps RLA = Rated Load Amps LRA = Locked Rotor Amps MCA = Minimum Circuit Ampacity

Vol tage Range Room Fan

Min Max RLA LRA Heat Type Heater kW Heater Amps MCA Maximum Fuse

197 228 2.7 6.8 23.6 96.0

207 253 2.7 6.8 23.6 96.0

197 228 2.7 6.8 15.0 88.0

207 253 2.7 6.8 15.0 88.0

414 506 2.7 2.2 7.1 41.0

FLA

Outdoor Fan

FLA

Outdoor Fan

FLA

Compressor Heating Options Power Supply

None, Hot Water, Steam -- -- 28.9 45

†Electric Heat

None, Hot Water, Steam -- -- 28.9 45

†Electric Heat

None, Hot Water, Steam -- -- 24.4 35

†Electric Heat

None, Hot Water, Steam -- -- 24.4 35

†Electric Heat

None, Hot Water, Steam -- -- 12.4 15

†Electric Heat

Compressor Heating Options Power Supply

None, Hot Water, Steam -- -- 39.0 60

†Electric Heat

None, Hot Water, Steam -- -- 39.0 60

†Electric Heat

None, Hot Water, Steam -- -- 28.3 40

†Electric Heat

None, Hot Water, Steam -- -- 28.3 40

†Electric Heat

None, Hot Water, Steam -- -- 13.8 20

†Electric Heat

Low (3-elem.) 10.0 48.1 63.5 70

High (6-elem.) 20.0 96.2 123.6 125

Low (3-elem.) 9.6 41.7 55.5 60

High (6-elem.) 19.2 83.3 107.5 110

Low (3-elem.) 10.0 27.8 38.1 40

High (6-elem.) 20.0 55.5 72.8 80

Low (3-elem.) 9.6 24.1 33.4 45

High (6-elem.) 19.2 48.1 63.5 70

Low (3-elem.) 9.6 12.0 18.4 20

High (6-elem.) 19.2 24.1 33.4 35

Low (3-elem.) 12.0 57.7 75.5 80

High (6-elem.) 24.0 115.4 147.6 150

Low (3-elem.) 11.5 50.0 65.9 70

High (6-elem.) 23.0 100.0 128.4 125

Low (3-elem.) 12.0 33.3 45.0 45

High (6-elem.) 24.0 66.6 86.6 90

Low (3-elem.) 11.5 28.9 39.5 40

High (6-elem.) 23.0 57.7 75.5 80

Low (3-elem.) 11.5 14.4 21.4 25

High (6-elem.) 23.0 28.9 39.5 40

Table 15: Electrical Data – Size 054 Models AZQ and AZU

Voltage

208/60/1

230/60/1

208/60/3

230/60/3

460/60/3

Vol tage Range Room Fan

Min Max RLA LRA Heat Type Heater kW Heater Amps MCA Maximum Fuse

197 228 2.7 6.8 28.6 118.0

207 253 2.7 6.8 28.6 118.0

197 228 2.7 6.8 19.6 123.0

207 253 2.7 6.8 19.6 123.0

414 506 2.7 2.2 10.0 62.0

† Electric heat options are without compressor and outdoor fan

FLA = Full Load Amps RLA = Rated Load Amps LRA = Locked Rotor Amps MCA = Minimum Circuit Ampacity

FLA

Outdoor Fan

FLA

Compressor Heating Options Power Supply

None, Hot Water, Steam -- -- 45.3 70

†Electric Heat

None, Hot Water, Steam -- -- 45.3 70

†Electric Heat

None, Hot Water, Steam -- -- 34.0 50

†Electric Heat

None, Hot Water, Steam -- -- 34.0 50

†Electric Heat

None, Hot Water, Steam -- -- 17.4 25

†Electric Heat

Low (3-elem.) 12.0 57.7 75.5 80

High (6-elem.) 24.0 115.4 147.6 150

Low (3-elem.) 11.5 50.0 65.9 70

High (6-elem.) 23.0 100.0 128.4 125

Low (3-elem.) 12.0 33.3 45.0 50

High (6-elem.) 24.0 66.6 86.6 90

Low (3-elem.) 11.5 28.9 39.5 50

High (6-elem.) 23.0 57.7 75.5 80

Low (3-elem.) 11.5 14.4 21.4 25

High (6-elem.) 23.0 28.9 39.5 40

AAF-HermanNelson Model AZ Unit Ventilators 47

Unit Selection

Table 16: Electrical Data – Size 024 Model AZR

Voltage

208/60/1

230/60/1

208/60/3

230/60/3

460/60/3

Vol tage Range Room Fan

Min Max RLA LRA Heat Type Heater kW Heater Amps MCA Maximum Fuse

197 228 2.7 2.9 11.4 52.0

207 253 2.7 2.9 11.4 52.0

197 228 2.7 2.9 7.9 59.0

207 253 2.7 2.9 7.9 59.0

414 506 2.7 1.2 3.9 29.7

† Electric heat options are with compressor and outdoor fan

FLA = Full Load Amps RLA = Rated Load Amps LRA = Locked Rotor Amps MCA = Minimum Circuit Ampacity

Table 17: Electrical Data – Size 036 Model AZR

Voltage

208/60/1

230/60/1

208/60/3

230/60/3

460/60/3

† Electric heat options are with compressor and outdoor fan

FLA = Full Load Amps RLA = Rated Load Amps LRA = Locked Rotor Amps MCA = Minimum Circuit Ampacity

Vol tage Range Room Fan

Min Max RLA LRA Heat Type Heater kW Heater Amps MCA Maximum Fuse

197 228 2.7 2.9 18.6 96.0

207 253 2.7 2.9 18.6 96.0

197 228 2.7 2.9 15.0 88.0

207 253 2.7 2.9 15.0 88.0

414 506 2.7 1.2 6.8 44.0

FLA

Outdoor Fan

FLA

Outdoor Fan

FLA

Compressor Heating Options Power Supply

None, Hot Water, Steam -- -- 19.9 30

†Electric Heat

None, Hot Water, Steam -- -- 19.9 30

†Electric Heat

None, Hot Water, Steam -- -- 15.5 20

†Electric Heat

None, Hot Water, Steam -- -- 15.5 20

†Electric Heat

None, Hot Water, Steam -- -- 8.8 15

†Electric Heat

Compressor Heating Options Power Supply

None, Hot Water, Steam -- -- 28.9 45

†Electric Heat

None, Hot Water, Steam -- -- 28.9 45

†Electric Heat

None, Hot Water, Steam -- -- 24.4 35

†Electric Heat

None, Hot Water, Steam -- -- 24.4 35

†Electric Heat

None, Hot Water, Steam -- -- 12.4 15

†Electric Heat

Low (3-elem.) 8.0 38.5 67.9 70 High (6-elem.) 16.0 76.9 116.0 125

Low (3-elem.) 7.7 33.3 61.5 70 High (6-elem.) 15.3 66.7 103.2 110

Low (3-elem.) 8.0 22.2 43.2 45 High (6-elem.) 16.0 44.4 71.0 80

Low (3-elem.) 7.7 19.2 39.5 40 High (6-elem.) 15.3 38.5 63.6 70

Low (3-elem.) 7.7 9.6 20.8 20 High (6-elem.) 15.3 19.2 32.8 35

Low (3-elem.) 10.0 48.1 88.9 90 High (6-elem.) 20.0 96.2 149.0 150

Low (3-elem.) 9.6 41.7 80.9 90 High (6-elem.) 19.2 83.3 133.0 150

Low (3-elem.) 10.0 27.8 59.0 60 High (6-elem.) 20.0 55.5 93.7 100

Low (3-elem.) 9.6 24.1 54.4 60 High (6-elem.) 19.2 48.1 84.5 90

Low (3-elem.) 9.6 12.0 27.4 30 High (6-elem.) 19.2 24.1 42.5 45

Table 18: Electrical Data – Size 044 Model AZR

Voltage

208/60/1

230/60/1

208/60/3

230/60/3

460/60/3

Vol tage Range Room Fan

Min Max RLA LRA Heat Type Heater kW Heater Amps MCA Maximum Fuse

197 228 2.7 6.8 23.6 96.0

207 253 2.7 6.8 23.6 96.0

197 228 2.7 6.8 15.0 88.0

207 253 2.7 6.8 15.0 88.0

414 506 2.7 2.2 7.1 41.0

† Electric heat options are with compressor and outdoor fan

FLA = Full Load Amps RLA = Rated Load Amps LRA = Locked Rotor Amps MCA = Minimum Circuit Ampacity

FLA

Outdoor Fan

FLA

Compressor Heating Options Power Supply

None, Hot Water, Steam -- -- 39.0 60

†Electric Heat

None, Hot Water, Steam -- -- 39.0 60

†Electric Heat

None, Hot Water, Steam -- -- 28.3 40

†Electric Heat

None, Hot Water, Steam -- -- 28.3 40

†Electric Heat

None, Hot Water, Steam -- -- 13.8 20

†Electric Heat

Low (3-elem.) 12.0 57.7 111.1 125 High (6-elem.) 24.0 115.4 183.2 200

Low (3-elem.) 11.5 50.0 101.5 110 High (6-elem.) 23.0 100.0 164.0 175

Low (3-elem.) 12.0 33.3 69.9 70 High (6-elem.) 24.0 66.6 1 11.5 110

Low (3-elem.) 11.5 28.9 64.3 70 High (6-elem.) 23.0 57.7 100.4 100

Low (3-elem.) 11.5 14.4 31.8 35 High (6-elem.) 23.0 28.9 49.9 50

48 McQuay Catalog 1620

Unit Selection

Table 19: Electrical Data – Size 054 Model AZR

Voltage

208/60/1

230/60/1

208/60/3

230/60/3

460/60/3

Vol tage Range Room Fan

Min Max RLA LRA Heat Type Heater kW Heater Amps MCA Maximum Fuse

197 228 2.7 6.8 28.6 118.0

207 253 2.7 6.8 28.6 118.0

197 228 2.7 6.8 19.6 123.0

207 253 2.7 6.8 19.6 123.0

414 506 2.7 2.2 10.0 62.0

† Electric heat options are with compressor and outdoor fan

FLA = Full Load Amps RLA = Rated Load Amps LRA = Locked Rotor Amps MCA = Minimum Circuit Ampacity

FLA

Outdoor Fan

FLA

Compressor Heating Options Power Supply

None, Hot Water, Steam -- -- 45.3 70

†Electric Heat

None, Hot Water, Steam -- -- 45.3 70

†Electric Heat

None, Hot Water, Steam -- -- 34.0 50

†Electric Heat

None, Hot Water, Steam -- -- 34.0 50

†Electric Heat

None, Hot Water, Steam -- -- 17.4 25

†Electric Heat

Low (3-elem.) 12.0 57.7 117.4 125

High (6-elem.) 24.0 115.4 189.5 200

Low (3-elem.) 11.5 50.0 107.8 110

High (6-elem.) 23.0 100.0 170.3 175

Low (3-elem.) 12.0 33.3 75.6 80

High (6-elem.) 24.0 66.6 117.3 125

Low (3-elem.) 11.5 28.9 70.1 80

High (6-elem.) 23.0 57.7 106.2 110

Low (3-elem.) 11.5 14.4 35.4 40

High (6-elem.) 23.0 28.9 53.5 60

AAF-HermanNelson Model AZ Unit Ventilators 49

Valve Selection

Face and Bypass End-Of-Cycle Valve Sizing & Piping

Note: Piping packages can be purchased from McQuay or

provided by others

MicroTech II face and bypass damper control requires an end-of-cycle (EOC) valve for each hydronic coil. End-ofcycle (or two position) valves are either full-open or fullclosed. To select an end-of-cycle valve:

1 Determine the flow of water and the correspond ing

pressure drop through the coil.

2 Obtain the pressure difference between the supply

and return mains.

3 Select a valve (Cv) on the basis of taking 10% of the

available pressure difference (at design flow) between the supply and return mains at the valve location. The valve should have a pressure drop less than or equal to that of the coil.

Table 20 gives the pressure drops at various water flow rates for the Cv of the valve listed. EOC valves for water applications can be either two-way or three-way.

Refer to the EOC valve label to determine the direction of flow. The EOC valve must be installed on the unit for which it was selected.

Table 20: Hot Water End-Of-Cycle Valve Selection By Pressu re Drop

2-Way Hot Water EOC Valve (7.0 Cv), FNPT, Normally Open

Water Flow GPM (L/s)

Water Pres. Drop Ft-H2O (kPa)

Water Flow GPM (L/s)

Water Pres. Drop Ft-H2O (kPa)

7 (0.44) 9.9 (0.62) 12.1 (0.76) 14 (0.88) 15.7 (0.99) 22.1 (1.39) 27.1 (1.71) 31.3 (1.98) 35.0 (2.20)

2.3 (6.9) 4.6 (13.8) 6.9 (20.7) 9.2 (27.6) 11.6 (34.5) 23.1 (69.0) 34.7 (103.4) 46.2 (138.0) 57.8 (172.4)

3-Way Hot Water EOC Valve (5.0 Cv), FNPT, Normally Open

5 (0.32) 7.1 (0.45) 8.7 (0.55) 10 (0.63) 11.2 (0.71) 15.8 (1.00) 19.4 (1.22) 22.3 (1.41) 25.0 (1.58)

2.3 (6.9) 4.6 (13.8) 6.9 (20.7) 9.2 (27.6) 11.6 (34.5) 23.1 (69.0) 34.7 (103.4) 46.2 (138.0) 57.8(172.4)

Hot Water EOC Valve Piping

Hot water EOC valves are furnished normally open to the coil. When the valve is de-energized (off) there is fu ll flow through the coil. Energizing the valve shuts off the water flow.

Figure 52. 2-Way Hot Water EOC Valve Piping

Return

Balancing & Shutoff Valve

Shutoff Valve

Supply

2-way EOC Valve

Unions

Unit Coil

Return

Supply

Figure 53. 3-Way Hot Water EOC Valve Piping

Return

Balancing &

(Bypass)

Supply

Shutoff Valve

Balancing Valve

3-way EOC Valve

Shutoff Valve

Union

Unit Coil

Return

Supply

Union

50 McQuay Catalog 1620

Valve Selection

Modulating Valve Sizing & Piping

Note: Piping packages can be purchased from McQuay or

provided by others

The unit ventilator control valve is expected to vary the quantity of water that flows through the coil in a modulating fashion. Any movement of the valve stem should produce some change in the amount of water that flows through the coil. Oversized control valves cannot do this.

For example, assume that, when the control valve is fully open, the pressure drop through the coil is twice as great as the drop through the valve. In this case, the control valve must travel to approximately 50% closed before it can begin to have any influence on the water flow through the coil. The control system, no matter how sophisticated, cannot overcome this. Oversized control valves can also result in hunting which will shorten the life of the valve and actuator and possibly damage the coil.

To correctly select the modulating valve:

Table 21: Hot Water M od ulating Valve Selection By Flow Rate

Valve Pressure Drop [ft of H2O (kPa)] at Listed Water Flow Rate [GPM (L/s)]

Cv Connection

1.3

1/2 inch

2.2

1/2 inch

4.4

1/2 inch

6.6

3/4 inch

7.5

3/4 inch

2.0

1/2 inch

4.0

1/2 inch

6.0

3/4 inch

Recommended

Flow Rates2 (.13)3(.19)4 (.25)5(.32)6 (.38)7(.44)8 (.51)9 (.57)

Hot Water 2-Way Modulating Valve, Normally Open

2 - 5 GPM

.13 -.32 L/s

5 - 8.5 GPM

.32 -.54L/s

8.5 -12.3 GPM .54 -.78 L/s

2-5 GPM

.78 - 1.1 L/s

Over 16.8 GPM

Over 1.1 L/s

5.5

12.3

21.8

34.1

(16.6)

(36.6)

(65.5)

––

––––––

–––––––– ––

–––––––– ––––––

7.5

(22.8)

–––––––––––––––

(102)

11.9

17.4

23.4

(35.9)

(51.0)

(69.7)

30.5

(91.0)

10.2

(30.3)

Hot Water 3-Way Modulating Valve, Normally Open

2 - 8 GPM .13 -.51 L/s 8 - 14 GPM .51 -.88 L/s

Over 14 GPM

Over.88 L/s

2.3

5.2

9.2

14.4

20.8

28.3

(6.9)

(15.9)

(27.6)

(43.5)

(62.1)

–––––––

–––––––– ––––

(84.8)

36.9

(110)

1 Determine the flow of water and the corresponding

pressure drop through the coil.

2 Obtain the pressure difference between the supply

and return mains.

3 Select a valve (Cv) from Table 21 on the basis of

taking 50% of the available pressure difference (at design flow) between the supply and return mains at the valve location. The valve should have a pressure drop greater than that of the coil. Whenever possible there should be at least 11 feet of water (5psi) (32.9 kPa) pressure drop across the valve.

Modulating valves for water applications can be either 2-way or 3-way. Refer to the modulating valve label to determine the direction of flow. The modulating valve must be installed on the unit for which it was selected.

The modulating valve furnished for steam applications is a 2-way, normally open to the coil configuration (see “Modulating Steam Valve Selection” on page 52 for application).

(.63) 11(.64)12(.76)

38.6 –––––––––––

(115.2)

12.9

16.0

(47.6)

14.4

(43.5)

19.3

(57.9)

17.4

(52.4)

(38.6)

––––––––––––

11.7

(35.2)

(.82)14(.88)15(.95)

23.0

27.0

(69.0)

(80.7)

11.0

12.9

(69.0)

(80.7)

20.8

24.4

(62.1)

(73.1)

–––– –––

15.0

(44.8)

28.3

(84.8)

9.7

(29.0)

(1.0)

17.2

19.5

(51.0)

(58.6)

10.5

(31.5

––– –––

11.2

12.8

(33.8)

(37.9)

(1.0)

(1.1)

22.0 –––

(66.2)

11.9

13.3

(35.7)

(40.0)

14.4

16.2

(43.5)

(48.3)

(44.1)

(53.8)

(1.2)

14.8

18.0

(1.3)

16.4

(49.0)

20.0

(60.0)

AAF-HermanNelson Model AZ Unit Ventilators 51

Valve Selection

Hot Water Modulating Valve Piping

Note: Piping packages can be purchased from McQuay or

provided by others

Modulating hot water valves are furnished normally open to the coil. When the valve is de-energized (off) there is full flow through the coil. Energizing the valve allows a varying amount of water to bypass the coil.

Figure 54. 2-Way Hot Water Modulating Valve Piping

Return

Balancing & Shutoff Va;ve

2-way

Modulating Valve

Shutoff Valve

Supply

Unions

Figure 55. 3-Way Hot Water Modulating Valve Piping

Return

3-way

Modulating Valve

N.C.

Common

N.O.

Balancing Valve

Unit Coil

Return

Supply

Balancing & Shutoff Valve

Union

Unit Coil

Return Supply

Steam Valve Sizing & Piping

End-Of-Cycle Steam Valve Selection

End-of-cycle, steam valves are either full-o pe n or fullclosed. To select an end-of-cycle steam valve:

1 Obtain the supply steam inlet pressure. 2 Determine the actual heat requirement of the space to

e heated.

3 Select a steam valve (Cv) based on taking 10% of the

t steam pressure. For example, for a system with

inle an inlet pressure of 2 psig, the valve should be sized based on a 0.2 psig pressure drop. The valve must have a capacity greater than or equal to that of the space to be heated.

Table 22 gives the steam capacity based on 10% of 2 psig and 5 psig inlet pressures at a 7.0 Cv rating.

Table 22: EOC Steam Va lve Selection

Valve Inlet Pressure Capacity MBh Capacity Watts

2 psig (13.8 kPa) 43.9 12854

Modulating Steam Valve Selection

The steam modulating control valve is expected to vary the quantity of steam through the coil. Any movement of the valve stem should produce some change in the steam flow rate. To select a modulating steam valve:

tain the supply steam inlet pressure.

1 Ob 2 Determine the actual heat requirement of the space to

e heated.

3 Select a valve (Cv) from Ta

ble 23, which gives the

capacity range based on a 60% pressure drop at the

Union

Shutoff Valve

low end of high end of the range.

For example: With 2 psig (13.8 kPa) inlet pressure, the

Supply

valve with port code 4, in the full open position, would have a 1.2 psig (8.3 kPa) pressure drop (60% of 2 psig) at 65 MBh (19,189 watts) and a 2 psig pressure drop at 82 MBh (24,125 watts). The valve should have a capacity less than or equal to the space to be heated.

, Normally OpenTable 23: Modulating 2-Way Steam Valve Capacity

Port

Code

Based on 1150 Btu/lb of steam

Cv Connection

2 1.3 1/2" (13mm) FNPT 19 24 32 38 5669 7128 9305 11270 3 2.2 1/2" (13mm) FNPT 33 41 54 65 9594 12062 15746 19072 4 4.4 1/2" (13mm) FNPT 65 82 107 130 19189 24125 31492 38144 5 5.5 3/4" (19mm) FNPT 82 103 134 163 23986 30156 39366 47681 6 7.5 3/4" (19mm) FNPT 112 140 183 222 32708 41122 53680 65019 7 10 1" (25mm) FNPT 149 187 244 296 43611 54829 71574 86692 8 14 1" (25mm) FNPT 208 262 342 414 61055 76760 100203 1213 69

2 psig Inlet Pressure 5 psig Inlet Pressure 13.8 kPa Inlet Pressure 34.5 kPa Inlet Pressure

Valve Capacity (MBh) Valve Capacity (W atts)

the range and 100% pressure drop at the

52 McQuay Catalog 1620

Valve Selection

Steam Valve Piping

Note: Piping packages can be purchased from McQuay or

provided by others

End-of-cycle (EOC) and modulating valves for steam applications are 2-way, normally open, angle pattern valves. When the coil is de-energized (off) the steam flows through the coil. Energizing the EOC valve sh uts off the flow of steam to the coil. Energizing the modulating valve varies the flow of steam in a modulating fashion. Refer to the steam valve label to determine the direction of flow. The steam valve must be installed on the unit for which it was selected.

All valves are shipped loose to help prevent shipping

damage and to provide the ins maximum flexibility in making the field piping connection. The valves are field piped by others. They are factory wired for field hook-up.

Notes:

1 Refer to

the label furnishe

determine direction of flow through the valve.

2 The control va

lve must be installed on the unit in which it was shipped. Indiscriminate mixing of valves among units can result in valves not proper ly sized for the desired flow rate.

e control valve should be installed so that there is

3 Th

" (51mm) minimum clearance to remove the actu ator from the valve body . Provide u nions for the removal of the unit coil and/or control valve. This is a future service consideration.

alling contractor with

d on 2-way valves to

Figure 56. 2-Way Steam Valve Piping

Supply

Shutoff Valve

Unit Coil

Supply

Steam Trap

Equalizing Line

Shutoff Valve

Return

AAF-HermanNelson Model AZ Unit Ventilators 53

Details & Dimensions

Coil Connections

The dimensional drawings on pages 55 and 56 show the location of coil connections for hot water and steam.

The following notes apply to all units:

1 All coils have same-end supply and return

nections.

con

2 Steam coils have a factory-installed pressure

qualizing valve and a 24" (610mm) long pressure

e equalizing line which terminates in a 1/2" M.P.T. fitting.

3 Steam or Hot Water connections are on the left end. 4 Electric heating coil power connections are right end

nly. Junction box has 1" (25mm) and 2" (51mm)

o (trade size) knockouts, 10-1/2" (267mm) from right end of the unit.

Table 25: Model AZ Basic Unit Data

Size S024 S036 S044 S054

Nominal Airflow - CFM (L/S)

No. of Fans 3 4 4 4

Room Fan Data

Room Fan Motor Horsepower

Outdoor Fan Motor Horsepower

Filter Data

Approx. Ship Weight - LBS. (Kg)

Coil Water Volume

Gallons (Liters)

Refrigerant Charge

Dia. In. (mm) 8.12 (206) 8.12 (206) 8.12 (206) 8.12 (206)

Width - In (mm) 8.25 (210) 8.25 (210) 8.25 (210) 8.25 (210)

Nom. Size - In. 10 x 48-1/2 x 1 10 x 60-1/2 x 1 10 x 36-1/2 x 1 10 x 36-1/2 x 1

Nom. Size - mm 254 x 1232 x 25 254 x 1527 x 25 254 x 927 x 25 254 x 927 x 25

Area - Ft² (M²) 3.37(.31) 4.2(.39) 5.08(.47) 5.08(.47)

1 Row Coil 0.31(1.17) 0.38(1.44) 0.44(1.67) 0.44(1.67) 2 Row Coil 0.57(2.16) 0.69(2.61) 0.82(3.10) 0.82(3.10)

Quantity 1.00 1.00 2.00 2.00

Ozs 125 140 150 150

1000(472) 1250(590) 1500 (708) 1500 (708)

1/4 1/4 1/4 1/4 1/3 1/3 3/4 3/4

885(402) 975(442) 1075(448) 1075(448)

5 Coil connecti

ons are 7/8" I.D. (female) and terminate

9" (229mm) from the end of the unit.

6 Steam coils are 1-1/8" female (sweat) connections

d terminate 9" (229mm) from the end of the unit.

7 All dimensions are approximate.

Table 24: Coil Water Capaci

Unit Series

1 Row Coil 2 Row Coil

024 036 044, 054

Gal Liter Gal Liter Gal Liter

0.29 1.10 0.35 1.32 0.41 1.55

0.52 1.97 0.63 2.38 0.74 2.80

ties (Gallons/Liters)

54 McQuay Catalog 1620

Details & Dimensions

Coil Connection Locations

Figure 57. Hot Water Coil Connection Locations

28" Type

13¾"

(349mm)

Wall

8½"

(216mm)

Wall

Room Projection

17¾"

(451mm)

22" (559mm)

DX Coil

Room Projection

13¾"

(349mm)

8½"

(216mm)

Wall

(295mm)

Wall

Room Projection

DX Coil

" (403mm)

Room Projection

Left End View Heating Coils

65 = 1-row Hot Water Coil 66 = 2-row Hot Water Coil

S = Supply R= Return

DX Coil

13¾"

(349mm)

8½"

(216mm)

(238mm)

" (346mm)

*Shading indicates portion of unit wall sleeve recessed into wall opening

13¾"

(349mm)

8½"

(216mm)

3.62" (92mm)

Notes:

1. Water coil connections are 7/8" (22mm) female sweat and

DX Coil

12.12"

(308mm)

terminate 9" (229mm) from the left end of the unit.

2. All coils have the supply and return connections in the left hand compartment.

3. All dimensions are approximate.

AAF-HermanNelson Model AZ Unit Ventilators 55

Details & Dimensions

Figure 58. Steam Coil Connection Locations

14½"

(368mm)

Wall

/16"

(259mm)

Wall

28" Type

Room Projection

Wall

Type

Room Projection

14½"

To Steam

(368mm)

Trap

14¼"

(362mm)

/16"

(418mm)

Type Type

Room Projection

/16"

(259mm)

(221mm)

(273mm)

Wall

/16"

10¾"

To Steam

Trap

Left End View

Heating Coils

68 = Low Capacity Steam Coil 69 = High Capacity Steam Coil

S = Supply

Room Projection

14½"

(368mm)

/16"

(259mm)



(162mm)

(205mm)

To Steam

Trap

/16"

14½"

(368mm)

/16"

(259mm)

Notes:



To Steam

Trap

(129mm)

/16"

1. Steam coil connections are 1-1/8" (29mm) female sweat and

*Shading indicates portion of unit wall sleeve recessed into wall opening

terminate 9" (229mm) from the left end of the unit.

2. All coils have the supply and drain to steam trap connections in the left hand compartment.

3. Steam coils have a factory installed pressure equalizing line which terminates in a 1/2" (13mm) MPT

4. All dimensions are approximate.

56 McQuay Catalog 1620

Details & Dimensions

Model AZ Self Contained Unit Dimensions, 024

Note: Valve control unit shown, however

face & bypass units have same external dimensions.

AAF-HermanNelson Model AZ Unit Ventilators 57

Details & Dimensions

Model AZ Self Contained Unit Dimensions, 036

Note: Valve control unit shown,

however face & bypass units have same external dimensions.

58 McQuay Catalog 1620

Details & Dimensions

Model AZ Self Contained Unit Dimensions, 044, 054

Note: Valve control unit shown, however

face & bypass units have same external dimensions.

AAF-HermanNelson Model AZ Unit Ventilators 59

Details & Dimensions

End Panels

Table 26: 1" (25mm) End Panel Dimensions

Top View

End View with

no Cutouts

End View with

2-1/2 x 7”

(64 x 178mm)

Cutout

End View with

4 x 18”

(102 x 457mm)

Cutout

16-5/8" (422mm)

Deep End Panel

16 5/8"

(422mm)

(178mm)

(64mm)

18"

(457mm)

(102mm)

(25mm)

27 7/

(708mm)

(25mm)

(708mm)

(25mm)

(708mm)

27 7/

19-5/8" (422mm)

Deep End Panel

(498mm)

2"(64mm)

(457mm)

(102mm)

(178mm)

18"

(25mm)

27 7/

(708mm)

(25mm)

27 7/

(708mm)

27 7/

(708mm)

21-7/8" (422mm)

Deep End Panel

(556mm)

(178mm)

2"(64mm)

18"

(457mm)

(102mm)

(25mm)

27 7/

(708mm)

(25mm)

27 7/

(708mm)

27 7/

(708mm)

28" (422mm)

Deep End Panel

28"

(711mm)

(25mm)

27 7/

(708mm)

End View with

4 x 22”

(102 x 559mm)

Cutout

22"

(559mm)

(102mm)

(25mm)

(708mm)

27 7/

(559mm)

(102mm)

22"

(25mm)

(708mm)

(25mm)

22"

(559mm)

4"(102mm)

27 7/

(708mm)

22"

(559mm)

4"(102mm)

(25mm)

(708mm)

27 7/

Table 27: 6" (152mm ) End Pan e l Di me nsions

28"

(711mm)

(152mm)

27"

(686mm)

3" (76mm)

Top View

End View with

no Cutouts

16 5/8"

(422mm)

(152mm)

27"

(686mm)

3" (76mm)

19 5/8"

(498mm)

(152mm)

27"

(686mm)

3" (76mm)

21 7/8"

(556mm)

(152mm)

27"

(686mm)

3" (76mm)

60 McQuay Catalog 1620

Details & Dimensions

Valve Dimensions

Note: Valves ordered separately

Face & Bypass End Of Cycle Valves

Figure 59. 2-Way EOC Valve

3-11/16"(94mm)

3-1/4"(83mm)

1-1/4"(32mm)

2-9/16"(66mm)

3/4"(19mm)

Modulating Valves

Figure 61. 2-Way Modulati ng Valve

4-3/32"

104mm

3-5/32"

80mm

6-13/16"

173mm

3-19/32"

80mm

11/32"

8mm

X, Y, Z Dimensions

Connection Cv X Y Z

3/4"(19mm) FNPT 7.0 11-1/16" (43mm) 1-1/16" (23mm) 3-5/8" (92mm)

*1"(25mm) FNPT 7.0 1-7/8" (47mm) 1" (25mm) 31-1/16" (94mm)

Figure 60. 3-Way EOC Valve Modulating Valves

3-11/16"(94mm)

3-1/4"(83mm)

1-1/4"(32mm)

1-11/6"

43mm

1-11/6"

43mm

3-5/8"(92mm)

2-3/8"(61mm)

3-1/16"(81mm)

1-7/16"

37mm

2-9/16"(66mm)

3/4"(19mm)

Table 28: Actuator Specifications

Control

Electrical

Stroke

Ambient

2 Position

24 VAC, 50/60 Hz

Power Stroke 9 to 11 seconds

Spring return 4 to 5 seconds

32°F to 125°F (0°C to 52°C)

Table 29: F&B Valve Body Specifications

2-Way Valve 3-W ay Valve

Connections

Static Pressure

Close-Off Pressure

Temperature

3/4" FNPT, 1" FNPT 3/4" FNPT

300 psi (2100 kPa) 300 psi (2100 kPa)

13 & 15 psi (90 & 103 kPa) 13 psi (90 kPa)

32°F to 200°F (0°C to 93°C) 32°F to 200°F (0°C to 93°C)

Figure 62. 2-Way Modulati ng Valve

3-15/16"

100mm

3-5/32"

80mm

4-3/32" 104mm

11/32"

8mm

6-13/16"

173mm

Table 30: 2-Way and 3-Way Modulating Valve Dimensions

Valve Size

in (DN)

1/2 (DN15) 3 (76) 13/16 (21) 1-9/16 (39) 1-13/16 (46) 8 (203) 3/4 (DN20) 3-7/32 (81) 15/16 (24) 1-5/8 (41) 2-1/8 (54) 8 (203)

1 (DN25) 4-1/8 (1 19) 1-5/32 (29) 1-3/4 (44) 2-9/16 (65) 9-7/32 (234)

1-1/4 (DN32) 4-23/32 (119) 1-11/32 (34) 2 (51) 2-25/32 (70) 9-7/32 (234)

A B C

N.O./N.C./

Three-Way

2-Way

N.O.

2-Way

N.C.

Three-

Way

Table 31: Actuat or Specifications

Control

Electrical

Transformer

Stroke

Operating Temp

35 to 250°F (2 to 121°C); 15 psig (103 kPa)saturated steam

Floating Point Modulating

20 to 30 VAC at 50/60 Hz or 24 VDC ± 10%

12 VA (class 2 power source)

29/32 in. (23mm) max. 76 seconds

Table 32: Modulati ng Valve Body Specifications

Connections

Static

Pressure

Fluid Temperature

400 psig (2.756 PA) up to 150°F; (66°C) decreasing to 365

Water

Steam

35 to 250°F (2 to 121°C); 15 psig (103kPa) saturated steam

psig; (2,515 kPa) at 248°F (120°C)

38 psig (262 kPa) Saturated steam at 284°F

AAF-HermanNelson Model AZ Unit Ventilators 61

Details & Dimensions

Wall Intake Louvers & Grilles

Louvers are available with a vertical blade con figur ation, constructed of heavy-gauge (unpain ted, p ainted, or clear anodized) aluminum.

• The louver is divided in half horizontally to prevent enser air recirculation.

cond

• A bird screen is provided on the leaving air side of the

ake louver.

int

• Louvers can be supplied with or without flanges:

• Flanged louvers are typically used for a panel wall

finish.

• Unflanged louvers are typically used for recessing a masonry wall.

into

• An optiona

l (factory-mounted) heavy-duty lattice exterior grille is available with horizontal and vertical lines that “line up” with the louver blades to present an aesthetic appearance.

vers are available in both horizontal and vertical

• Lou bla

de configurations:

Figure 63. Typical W a ll Lo uver and Grille

Factory Mounted

Bird Screen

Fasteners

Information

Labels

Frame

Optional

Flanges

Splitter Lines Up with Wall

Sleeve Splitter

Figure 65. Grille Detail

/2"

(63.5 mm)

W (see Table)

A (see Table)

28"

(711 mm)

/8"

14±

(356±3.2mm)

1 1/4"

(31.8 mm)

/8"

(22.2 mm)

Optional Flange

Table 33: W a ll Lo uv er Dimensions (W)

Unit Size

024

036

044, 054

Louver Size (Height x W)

28” x 84”

(711 x 2134)

28” x 96”

(711 x 2438)

28” x 108”

(711 x 2743)

Discharge Air

Opening(A)

9”

(229mm)

9”

(229mm)

7”

(178mm)

Note: All dimensions are approximate and subject to change

without notice. Refer to approved submittal prints for rough-in details and construction purposes, and for recommended wall opening size.

Optional Factory

Mounted

Exterior Grille

Mechanical

Fasteners

Figure 66. Vertical Blade Louver, Without Flange

Inside View

Condenser

Discharge Air

Figure 64. Vertical Blade Louver, Without Flange

Outside View

Condenser

Discharge Air

Condenser

Inlet Air

Bird Screen on

Side Toward Unit

Condenser

Inlet Air

Louver with

Weep Holes

62 McQuay Catalog 1620

Details & Dimensions

VentiMatic Shutter Assembly

Notes:

1 Horizontal blade louver shown. Vertical blade louver

also available with Ventimatic shutter.

2 Optional exterior grille matches unit

ventilator louver

in material and design. Mounted in wall louver.

Figure 67. Ventimatic Shutter Assembly With Optional Grille

3 Optional interior grille mounting hardware is

included.

4 Louver leaves seal against plate to pr

event air

infiltration.

not

Table 34: Ventimatic Shutter Assembly Dimensions & Max Air

Exterior Grille

Width A

inches mm inches mm inches mm

23-3/4 603 24 610 27 686 24-1/4 616 10-1/2 267 1 0 500 236 36-3/4 933 36 914 39 991 36-1/4 921 10-1/2 267 0 1 750 354 47-3/4 1213 48 1219 51 1295 48-1/4 1225 10-1/2 267 2 0 1000 472 59-3/4 1518 60 1524 63 1600 60-1/4 1530 10-1/2 267 1 1 1250 590 71-3/4 1822 72 1829 75 1905 72-1/4 1835 10-1/2 267 0 2 1500 708

Louver

Width B

Interior Grille

Width C

Recommended Wall Opening

Length Width

inches mm inches mm

Capacities

For Louver

Max Number of Ventimatic

rs To Mount On

Shutte

Standard Louver

24” (610mm)

Shutter

36” (914mm)

Shutter

Ventimatic

Shutter(s) Max

Air Capacity

inches mm

AAF-HermanNelson Model AZ Unit Ventilators 63

Details & Dimensions

Sink & Bubbler Cabinet

Notes:

1 Sink top is one-piece, stainless steel construction with

sound-deadening coating on the under side. Front edge has raised lip continuously from end to end.

2 Sliding doors available in decorator colors.

Figure 68. Top View - Single Bowl & Bowl With Bubbler

17-7/8" 454mm

9-5/16"

228mm

Figure 69. Front & End Views

1/8" (3mm)

16" 392mm

11-1/8"

283mm

Faucet

Bubbler

3 Sink and bub

bler basin drains equipped with 1-1/2"

O.D. tail pieces, all chrome plated brass.

4 Sink faucet and bubbler valve are shipped loose for

field ins

5 Sink and bub

tallation by the installing contractor.

bler top is designed to project 1/16" higher and 3/16" deeper than the adjoining cabinets, unit ventilator or end panels.

12" 25mm

9-1/8" 232m

427mm

16-13/16"

17-7/8" 454mm

9-5/16"

228mm

427mm

16-13/16"

16" 392mm

21" 533mm

11-1/8"

283mm

16-13/16"

427mm

Bubbler

(4) 7/8" (22mm) Dia.

26"

660mm

25mm

3"(76mm)

Knockouts In Back For Anchoring To Wall

1-9/16"

40mm

21-7/8" (556mm)

16-13/16"(427mm)

21-7/8"(556mm) Deep Cabinet

Right End View

48" (1219mm)

Front View

23"

584mm

127mm

Door Lock (Optional)

2-1/2" 64mm

21-7/8" (556mm)

16-13/16"(427mm)

3"(76mm)

30-1/8" 765mm

13-1/2"

765mm

6-1/2"

165mm

21-7/8"(556mm) Deep Cabinet

With Radiation Bar Grille

Radiation Bar Grille

23"

584mm

127mm

30-1/8"

765mm

16-13/16"(427mm) Deep Cabinet

Right End View

21-7/8" (556mm)

16-13/16"(427mm)

3"(76mm)

21-7/8"(556mm) Deep Cabinet

With Draftstop Bar Grille & Damper

28-1/8" 714mm

23"

584mm

127mm

Draftstop Bar Grille & Damper

64 McQuay Catalog 1620

Details & Dimensions

Filler Sections & Utility Compartment

Filler sections are furnished in 18" and 24" lengths. They are provided with enough hardware to assemble one right hand and one left hand fi ller having a combined

after cutting is 3". The filler section may be used between a cabinet and the wall, between a unit and the wall, between a unit and cabinets, or between cabinets.

length of 18"/24" or less. The minimum length of one filler

Figure 70. Wall Filler Section With Painted Metal Or Laminate Top

Painted Metal Top

Attach to wall,

left or right end.

Front

Kickplate

Front End Cap

Figure 71. Corner Filler Sections

Attach to unit

ventilator, storage

cabinet right.

Top End Cap

Attach to unit ventilator or utility cabinet right or left end.

Painted Metal Top

Support Strip

Attach to wall,

left or right end.

Front Kickplate

Laminate Top

Mounting Angle for attaching top to unit ventilator, utility cabinet and back wall.

Side Panel Adapter for attaching top to storage cabinet.

Attach to unit ventilator or storage cabinet right or left end.

Front End Cap

Laminate Top

Support Strip

Attach to wall

Figure 72. 12" Utility Compartment

Dim. A MM Dim. B MM

16-5/8 442 3 76

21-7//8 556 5-1/4 133

30"

762mm

3" 76mm

12"

305mm

3" (76mm)

Corner Post

Kickplate

28"

660mm

14" 356mm

Attach to wall

Corner Post

Kickplate

12"

305mm

12"

305mm

1" 25mm

AAF-HermanNelson Model AZ Unit Ventilators 65

Details & Dimensions

Shelf Storage Cabinets

Figure 73. Shelf Storage Cabinets, Front View

25mm

24, 36, 48 & 60" open

(610, 914, 1219 & 1524 mm)

25mm

72, 84, 96, 108 & 120" open (1829, 2134, 2438, 2743 & 3048mm )

10" 254mm

762mm

13-1/2" 343mm

6-1/2" 165mm

1-9/16" (40mm)

Removable end panels

Shelf adjustable in 2" (51mm) increments

4-7/8" (22mm) diameter knockouts in back for anchoring to wall

Front skirt with air inlet for radiation style cabinet

Front skirt for standard and draftstop style cabinet

Figure 74. Shelf Storage Cabinets, Front View

25mm

Front skirt with air inlet for radiation style cabinet

24, 36, 48 & 60" open

(610, 914, 1219 & 1524 mm)

Door lock (optional)

Removable end panels

Sliding doors

Front skirt for standard and draftstop style cabinet

30"

762mm

30"

25mm

Shelf adjustable in 2" (51mm) increments

Removable end panels

Front skirt with air inlet for radiation style cabinet

72, 84, 96, 108 & 120" open (1829, 2134, 2438, 2743 & 3048mm )

Door lock (optional)

Removable end panels

Front skirt with air inlet for radiation style cabinet

Door pull

4-7/8" (22mm) diameter knockouts in back for anchoring to wall

Front skirt for standard and draftstop style cabinet

Sliding Doors

Front skirt for standard and draftstop style cabinet

10" 254mm

30"

762mm

13-1/2" 343mm

6-1/2"

165mm

1-9/16" 40mm

30"

762mm

Figure 75. Right End View - 16-5/8" (442 mm) Deep Shelf S

16-5/8" (442mm)

13-11/16" (348mm)

27"

30"

762mm

686mm

3" (76mm)

16-5/8" (442mm)

13-11/16" (348mm)

27"

Piping

area

2-15/16

(75mm)

23"

584mm

5" (127mm)

30"

762mm

686mm

3" (76mm)

orage Cabinets With 11-1/2" (292mm) Shelf & Metal Top

16-5/8" (442mm)

13-11/16" (348mm)

Piping

area

27"

Piping

area

2-15/16" (75mm)

Radiation bar grille

23"

584mm

5" (127mm)

30"

762mm

686mm

3" (76mm)

2-15/16" (75mm)

Draftstop bar grille & damper

23"

584mm

5" (127mm)

Standard Cabinet Cabinet With Radiation Bar Grille Cabinet with DraftStop Bar Grille & Damper

66 McQuay Catalog 1620

Details & Dimensions

Figure 76. Right End View - 21-7/8" (556 mm) Deep Shelf Storage Cabinets With 13-1/2" (343mm) Shelf With Metal Top

21-7/8" (556mm)

16-1/16" (408mm)

5-13/16 148 mm

21-7/8" (556mm)

16-1/16" (408mm)

5-13/16" (148)

Radiation bar grille

21-7/8" (556mm)

16-1/16" (408mm)

5-13/16"(148 mm)

Draftstop bar grille & damper

30"

762mm

27"

686mm

3" (76mm)

Piping

area

23"

584mm

127mm

30"

762mm

27"

686mm

3" (76mm)

Standard Cabinet Cabinet With Radiation Bar Gr ille Cabinet with DraftStop Bar Grille & Damper

Figure 77. Right End View - 16-5/8" (442 mm) Deep

16-5/8" (442mm)

30"

762mm

686mm

13-11/16" (348mm)

Piping

area

27"

2-15/16

(75mm)

23"

584mm

30"

762mm

27"

686mm

Piping

area

23"

584mm

127m

30"

762mm

27"

686mm

3" (76mm)

Piping

area

23"

584mm

5" (127mm)

Shelf Storage Cabinets With 11-1/2" (292mm) Shelf With Laminate Top

27"

16-5/8" (442mm)

13-11/16" (348mm)

Piping

area

2-15/16" (75mm)

Draftstop bar grille & damper

23"

584mm

16-5/8" (442mm)

13-11/16" (348mm)

Piping

area

2-15/16" (75mm)

Radiation bar grille

23"

584mm

30"

762mm

686mm

3" (76mm)

5" (127mm)

3" (76mm)

5" (127mm)

3" (76mm)

5" (127mm)

Standard Cabinet Cabinet With Radiation Bar Grille Cabinet with DraftStop Bar Grille & Damper

Figure 78. Right End View - 21-7/8" (556 mm) Deep Shelf S

21-7/8" (556mm)

5-13/16

148 mm

23"

584mm

127mm

16-1/16" (408mm)

30"

762mm

27"

686mm

3" (76mm)

30"

762mm

686mm

3" (76mm)

16-1/16" (408mm)

Piping

area

27"

torage Cabinets With 13-1/2" (343mm) Shelf With Laminate Top

21-7/8" (556mm)

Piping

area

5-13/16" (148)

Radiation bar grille

23"

584mm

127mm

30"

762mm

27"

686mm

3" (76mm)

21-7/8" (556mm)

16-1/16" (408mm)

Piping

area

5-13/16"(148 mm)

Draftstop bar grille & damper

23"

584mm

5" (127mm)

Standard Cabinet Cabinet With Radiation Bar Grille Cabinet with DraftStop Bar Grille & Damper

AAF-HermanNelson Model AZ Unit Ventilators 67

Wiring Diagrams

Typical MicroTech II Wiring Diagrams

Note: For troubleshooting, refer to unit-mounted schematic

Figure 79. MicroTech II Wiring Diagram

68 McQuay Catalog 1620

Wiring Diagrams

Typical Wall Sensors Diagram

Figure 80. Wall-Mounted Temperature Sensor Wiring for Wall Sensor

Power & Control Field Wiring

Figure 81. External Input Wiring Examples with or without Daisy Chaining of Units

Unit Ventilator #1

Connector

GND

Comm

BI-6 BI-5 BI-4 BI-3

896

908A

907A

906A 905A

904A

Wire

Caps

Shield

Unit Ventilator #2

Connector

GND

Comm

BI-6 BI-5 BI-4 BI-3

Unit Ventilator #3

Connector

GND

Comm

BI-6 BI-5 BI-4 BI-3

896 908A 907A 906A 905A 904A

Wire

Caps

Wire

Caps

Shield

Additional Units

External Input

Option 4 Device

(by Others)

External Input

Option 3 Device

(by Others)

Ventilation Lockout

(default) or

Exhaust Interlock

External Input

Option 2 Device

(by Others)

Remote Shutdown

Factory Wiring Field Wiring (by Others) External Device (by Others)

External Input

Option 1 Device

(by Others)

Unoccupied

AAF-HermanNelson Model AZ Unit Ventilators 69

Wiring Diagrams

Figure 82. External Output Wiring - Single Unit

Unit Ventilator

UVC

xBO-2

Comm

xBO-1

BO-6 BO-6

Comm

24vac Supply

24vac Comm

Connector

601A 602A 603A 604A 605A 606A 608A 610A

Wire

Caps

Shield

Factory Wiring Field Wiring (by Others) External Device (by Others)

External Output

Option 1 Device

(by Others)

Lights On/Off

Signal

Motorized Water

Valve Open/Close

External Output Option 2 Device

(by Others)

Fault Indication

Pump Restart

Figure 83. External Output Wiring - Multiple Units Shown

Unit Ventilator #1

Connector

UVC

XBO-2 Comm

XBO-1

BO-6 BO-6

Comm

24vac Supply 24vac Comm

Unit Ventilator #2

Connector

UVC

XBO-2 Comm

XBO-1

BO-6 BO-6

Comm

24vac Supply 24vac Comm

Unit Ventilator #...X (last unit)

Connector

UVC

XBO-2 Comm

XBO-1

BO-6 BO-6

Comm

24vac Supply 24vac Comm

601A 602A 603A 604A 605A 606A 608A 610A

601A

602A

603A

604A 605A 606A 608A 610A

Wire Caps

Wire

Caps

Wire

Caps

Shield

Additional Units

Signal

External Output Option 3 Device

(by Others)

Auxiliary Heat

Signal

Exhaust Fan

On/Off Signal

External Output Option 2 Device

(by Others)

Fault Indication

Pump Restart

Signal

Factory Wiring Field Wiring (by Others) External Device (by Others)

70 McQuay Catalog 1620

Guide Specifications

AAF-HermanNelson Unit Ventilator Model AZ Guide Specifications

General

Furnish and install where shown on plans, a complete self-contained, air cooled, heating and cooling unit ventilator. This unit shall meet capacities, airflow and configuration as shown on unit schedule.

Each standard unit must be listed by Underwriters

aboratories Inc. (U.L.) as complying with all safety

L standards.

The units shall ship fully assembled with the exception of

end panels which shall be packaged separately to

the allow easy access for piping and electrical rough-in. (Option: Wall sleeves shall be shipped in advance of unit for rough-in.)

Unit Construction

All internal sheet metal parts subject to corrosion must be made of galvanized steel. The entire frame must be welded construction to provide strength and rigidity. Frames assembled with sheet metal fasteners are not acceptable.

Cabinets

Exterior cabinet panels shall be constructed of heavygauge steel and every exposed corner must be welded and ground smooth for appearance and durability. All surfaces shall be cleaned and phosphatized, then painted with an oven baked powder paint. Top surface shall be Charcoal Bronze textured powder paint to resist scratching and hide fingerprints. Front access panels and top access door shall be supplied with tamper resistant fasteners.

Removable discharge grille shall be continuous, round edged, steel bars to provide a 10degree vertical deflection.

Adjustable side deflection vanes shall be provided

eneath the discharge grille to give optimal lateral air

b distribution. (Option: A 1/4" (6mm) mesh screen shall be provided beneath the discharge grille to protect against objects being dropped through the discharge grille.)

constructed of

Room Air Fans and Motor

The motor and fan assembly shall be low speed design and shall be double inlet, forward curved centrifugal type with maximum fan speed of 1100 rpm. Fan wheels shall be constructed of dark, high density, injection molded polypropylene having high impact strength, chemical resistance and thermal stability. Assembly shall be direct

drive type and shall be statically and dynamically balanced. Motor shall be permanent split capacitor (PSC) plug-in type located out of the airstream and have an internal thermal overload device (auto-reset). Fan speeds shall be controlled by High-Med-Low-Off switch. Fan/coil arrangement shall be draw-thru design for uniform coil face velocity and discharge air temperature.

Fan motors and controls shall have each hot line

otected by factory installed cartridge type fuse(s) The

pr unit manufacturer shall provide one (1) spare motor for each size and type of motor furnished as part of a unit ventilator, except units having double extended shaft motors shall be provided with one (1) spare fan board assembly for each unit size.

All components of the fan/motor assembly shall be

emovable from the front of the unit. The motor and fan

r shaft shall have sleeve type bearings with precision tolerances and shall not require oiling more than once annually.

Condenser Fans and Motors

The fan board and fan housings shall be constructed of galvanized steel. The fan motor and fan shaft shall have permanently lubricated ball bearings. Motor shall be permanent split capacitor (PSC) type. Fan wheels shall be forward curved centrifugal type.

(Optional) Face and Bypass Damper

Each unit shall be provided with a factory-installed face and bypass damper, constructed of aluminum. The long sealing surfaces of the damper shall seal positively against stops fitted with extruded EPDM rubber seals. Face and bypass damper stop s not fitted with sea ls shall not be acceptable. The damper ends shall have blended mohair seals glued along the ends for a positive seal. Plastic clip-on brush end seals will not be acceptable. The unit design shall incorporate the face and bypass damper to prevent coil surface wiping and be before the fan in a draw through configuration. Face and bypass damper positioned in the direct discharge of the room fan is not acceptable. The face and bypass damper shall be arranged so a dead air space results between the coil and the damper in a full bypass condition to minimize heat pick up.

Outdoor and Room Air Dampers

Each unit shall be provided with separate room air and outdoor air dampers. The room air damper shall be constructed of aluminum and counterbalanced against

AAF-HermanNelson Model AZ Unit Ventilators 71

Guide Specifications

back pressure. Outdoor air damper shall be two-piece, double wall construction with 1/2" (13mm) thick, 1.5 lbs. (.68 kg) density fiberglass insulation sandwiched between welded galvanized steel blades. Outdoor air damper shall have additional foam insulation on the exterior of the blades and end partitions. Dampers shall be fitted with blended mohair seals along all sealing edges. Damper bearings shall be made of nylon or other material which does not require lubrication.

Refrigeration System

The refrigeration section shall be constructed of galvanized steel and shall include a factory sealed, factory piped assembly consisting of a hermetically sealed compressor , a conden ser coil, cond enser fan and motor, an d an evaporator coil. No condensate drain piping system shall be required as the cooling condensate is to be disposed of by directing it into the condenser fan scrolls for re-evaporator on the hot condenser coil. The equipment manufacturer is to be fully responsible for the integrity of the refrigerant piping and the entire refrigeration circult, including compressor. Condenser and evaporator coils shall be fully assembled and tested prior to shipment. The motor compressor unit shall be vibration isolated internally and externally and shall be connected in such a manner as to prevent transmission of vibration to other components within the section.

Single-phase only: Single-phas permanent split capacitor (PSC) compressor motor with compressor start relay.

Units with three-phase power: Shall utilize three-phase

pressors for balanced electrical compressor loads.

com The condenser coil shall be constructed of copper tubes

chanically expanded to embossed aluminum plate

me fins. The unit shall be so designed as to allow access to the entering side of the condenser coil for cleaning without opening the sealed refrigeration circuit. The evaporator coil shall be constructed of copper tubing having embossed aluminum plate fins mechanically bonded thereto and shall be positioned above a plastic drain pan.

Refrigerant shall be metered by a thermostatic

pansion valve in lieu of capillary tubing to achieve

ex evaporator performance and to protect the compressor from floodback of liquid refrigerant. The refrigerant section shall be adequately insulated to prevent “sweating.”

The unit shall be furnished and wired with compressor

rmal/current overload and high pressure cutout.

the Gauge ports shall be provided to allow reading of

e units shall have

refrigerant pressures at the suction and discharge of the compressor. Compressor shall be equipped with internal pressure relief valve to protect against excessive pressure buildup.

(Optional) Electric Coils

Heating elements shall be of the open wire type. Electric heat shall be controlled in [three] stages. A capillary type high limit thermostat shall be provided to disconnect the heating elements through backup contactors if an overheat condition is detected. A front panel interlock switch shall be furnished to de-energize the electric resistance heating element when center front panel is opened.

(Optional) Hot Water Coil

Coil shall be aluminum plate fin and copper tube construction. Coil shall be suitable for 150 psi working pressure. Coil shall be provided with an accessible manual air vent at the high point of the coil and a threaded drain plug at the low point of the coil.

Contractor shall prov shutoff valves and union connections in both the supply and return piping connections to permit removal of the unit from the wall sleeve for servicing.

Option: C way) modulating control valve and shall be factory wired by the unit ventilator manufacturer. Valve shall be field installed and piped by the installing contractor.

— OR — Option: Co

and bypass damper. Coil shall have a 3-way, 2-position, end-of-cycle valve to shut off water flow when heating is no longer required. V alve and coil return shall have union connections. Valve shall be factory wired by the unit ventilator manufacturer and shall be field installed and piped by the installing contractor.

oil shall be controlled by a 3-way (optional 2-

il shall be controlled by a modulating face

ide all necessary balancing valves,

(Optional) Steam Coil

Coil shall be aluminum plate fin and copper tube construction. Coil shall be double tube (D T) ste am distributing, freeze resistant type. Coil shall be pitched to insure complete condensate removal for freeze protection and elimination of “water hammer.”

Contractor shall provide all necessary shutoff valves and

ion connections in both the supply and return piping

un connections to permit removal of the unit from the wall sleeve for servicing.

A pressure equalizing device (vacuum breaker) shall be factory inst

alled to prevent the retention of condensate in

72 McQuay Catalog 1620

Guide Specifications

the coil. The installing contractor shall connect the device to the return line beyond the trap using the tubing provided. Steam tra p shall be furnished and field installed by the installing contractor.

Option: Co control valve and shall be factory wired by the unit ventilator manufacturer. Valve shall be field installed and piped by the installing contractor.

— OR — Option: Co

and bypass damper. Coil shall have a 2-way, 2-position, end-of-cycle valve to shut off steam when heating is no longer required. Valve and coil supply shall have union connections. Valve shall be factory wired by the unit ventilator manufacturer. Valve shall be field installed and piped by the installing contractor.

il shall be controlled by a 2-way, modulating

il shall be controlled by a modulating face

(Optional) Up-feed Piping.

Option: Up-feed piping stub-up within the unit end

compartment requires the installing contractor to furnish union connection at the floor line in the supply and return lines with shutoff valves below the floor line. This is required to permit unit installation and removal for servicing.

Option: Up external to the unit within a removable 6", (152m m ) wide end panel. The shutoff valves and union connections shall be located within the 6" (152mm) wide end panel.

-feed piping stub-up shall be brought up

Filter

Filter shall be one-piece design located to provide filtration of the outdoor air/return airflow. Separate filters for outdoor air and return air are not acceptable. Throwaway filter shall be factory furnished initially installed in the unit.

multi-functional material that serves as a sound barrier, an absorber of sound and also must act as a decoupler to the compressor enclosure. This multi-functional material shall have a mylar coating on the face to act as a sound reflector and to increase the strength of the material. Damping material shall be textured foam type.

The exterior of the compressor compartment shall be

ted with a high density damping material to eliminate

coa impact noise and vibration. The right-hand front panel and the hinged top access door shall be coated with a high density material to minimize noise and vibration.

Temperature Controls

The unit ventilator manufacturer shall provide factory installed, calibrated, and tested temperature controls. Units that are capable of providing up to 100% outside air shall provide a microprocessor-based Direct Digital Control (DDC) that can monitor conditions and automatically adjust unit operations to maintain these requirements. This DDC control shall have the following tenant adjustments: (1) room temperat ur e se tp oin t, (2 ) minimum percent outdoor air setting, and (3) unoccupied setpoint (offset). An LED status/fault indicator shall be furnished for inspection and a communications port shall be incorporated to allow manipulation by a remote PC. The remote PC shall be able to access and change pertinent operating and room conditions from a remote location. The microprocessor-based control must be capable of communicating to a local IBM-compatible PC using the RS-232 protocol. When using this remote PC, the unit must be capable of reacting to changes made by the remote PC. The remote PC must also be able to access all pertinent operating and room conditions.

Room Temperature Sensor and Tenant Override Options

Option: Fur

throwaway filters. Option: Fur

as final filter. Option: Fur

glass fiber media) filters as final filter. Option: Fur

filter media.

Acoustical Features

The compressor shall be mounted on compressor isolators for external vibration isolation. Compressor enclosure panels shall be 16-gauge minimum. Complete interior of compressor compartment shall be lined with a

AAF-HermanNelson Model AZ Unit Ventilators 73

nish _____________ extra set(s) of

nish one set of wire mesh permanent filters

nish one set of renewable (metal frame with

nish _____________ roll(s) of renewable

Unit-Mounted

Units shall have a temperature sensor located in a sampling chamber to allow a constant circulation of room air to flow across the sensing device. The sampling chamber shall be designed in such a manner that will ensure rapid and accurate sensing of room air.

Option: A un supplied.

it mounted tenant override device shall be

Wall-Mounted Sensor

Units shall have a temperature sensor with status LED funnished for mounting to the wall. [Option: In addition, a tenant override switch shall be furnished as part of the wall mounted sensor.]

Guide Specifications

Wall-mounted Sensor with Tenant Override and Setpoint Adjustment

A sensor with integral tenant override and status LED shall be furnished with the unit ventilators. This sensor shall also contain a manually adjustable temperature setting allowing the controller setpoint to be increased or decreased by 3°F (2°C).

(Optional) Night Control with Unit-mounted Time Clock

Each unit shall be furnished with a unit-mounted, field programmed time clock for day/night changeover. This clock will provide up to 150 hours of operation during a power outage.

Wall Sleeve

The galvanized steel, one-piece wall sleeve shall be set in a wall opening and butted up directly against the intake louver. Where it is not possible to butt the wall sleeve against the wall intake louver, the contractor shall fabricate and install horizontal air splitters between the louver and wall sleeve to provide an airtight separation between condenser discharge and return air. The wall sleeve is to be permanently fastened in place and shall be suitably sealed, caulked or grouted by the contractor around the entire perimeter to prevent air leakage.

The wall sleeve shall be fitted with an e box containing a main “on-off ” switch. All field wiring connections shall be made in this wall sleeve junction box.

(It shall be the installing contrac make the final load side power wiring connections between the wall sleeve junction box and the unit terminal block (including the wiring going to the electr ic heating elements.The wall sleeve shall be cartoned

tor’s responsibility to

lectrical junction

separately and shipped to the jobsite preceding the unit ventilator. Junction box shall ship separately for field installation.)

Wall Intake Louver

The louver shall be supplied by the unit manufacturer and shall be of heavy-gauge (unpainted, p ainted, or clear anodized) aluminum construction. The louver shall be of the vertical blade type and shall be divided in half horizontally across the louver to prevent condense r air recirculation. A 1/2" (13mm) square mesh bird screen shall be provided on the backside of the wall intake louver. All louvers shall be 28" (711mm) high by 2-1/2" (57mm) thick and suitable for both masonry and panel wall construction. The frame of the louver shall have weep holes along the bottom. Lintels shall be provided by the contractor above the louver opening.

Optional: Heavy-d lines shall “line up” with the louver blades to present an aesthetic appearance. Grille shall be fabricated from mill finish aluminum.

uty lattice grille horizontal and vertical

Drain Pan

All units shall have a drain pan constructed of corrosionresistant composite material.

Agency Listing

Unit ventilators shall be listed by Underwriters Laboratories Inc. (U.L.) for the United States and Canada. Motors shall conform to the latest applicable requirements of NEMA, IEEE, ANSI, and NEC standards. Unit to be certified and labeled compliant with the seismic design provisions of the International Building Code (IBC) Chapter 16 and independent test agency requirements of Chapter 17.

74 McQuay Catalog 1620

Guide Specifications

AAF-HermanNelson Model AZ Unit Ventilators 75

McQuay Training and Development

Now that you have made an investment in modern, efficien t McQuay equipment, its care should be a high priority. For training information on all McQuay HVAC products, please visit us at www.mcquay.com and click on training, or call 540-248-9646 and ask for the Training Department.

Warranty

All McQuay equipment is sold pursuant to its standard terms and conditions of sale, including Limited Product Warranty. Consult your local McQuay Representative for warranty details. Refer to Form 933-43285Y. To find your local McQuay Representative, go to www.mcquay.com.

This document contains the most current product info rm a tio n as of this pr int ing . Fo r th e mo st up - to- d ate pro d uc t information please go to www.mcquay .com.

Products manufactured in an ISO Certified Facility

McQuay AZR User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Introduction

Nomenclature

AAF-HermanNelson Classroom Unit Ventilators

Built To Last

Heavy Duty Frame Construction

Rugged Exterior Finish

MicroTech II Control For Superior Performance, Easy Integration

The Model AZ Floor Unit

Features & Benefits

GentleFlo Delivery

The Right Amount of Fresh Air and Cooling

Economizer Operation

Part-Load Variable Air Control

Precise Temperature and Dehumidification Control

Draw-Thru Design For Even Discharge Temperatures

Face & Bypass Design For Better Temperature Control

Active Dehumidification (Reheat)

Increased Coil Freeze Protection

Low Installation Costs

Perfect For Both New & Retrofit Applications

Built In Flexibility

Controls Flexibility

MicroTech II Control Options Further Reduce Operating Costs

Two Stage Compressor

Easy To Maintain

Fan Deck

Heavy-Duty Discharge Grille

Internal Fan Deck Components

Tamper-Resistant Fasteners

Sectionalized Access Panels And Doors

Filter

Built To Last

Durable, Energy Efficient Fan Motors

Durable Damper Design

MicroTech II Controls

MicroTech II Controls For Superior Performance, Easy Integration

Three Control Levels

Control Modes and Functions

Occupancy Modes

Economizer Modes

Night Purge Mode

Freeze Prevention Mode

Face and Bypass Control Units

Valve Control Units

Emergency Heat Mode

External Input Functions

External Output Functions

Demand-Controlled Ventilation (Optional)

Part Load Variable Air Control

Active Dehumidification Control (Reheat)

DX System Control

System Components

Unit Ventilator Controller

Local User Interface

Optional Communication Modules

Sensors

MicroTech II Sensor and Component Locations

Actuators

Optional Time Clock For Stand-Alone Units

ServiceTools™

Accessories

Wall Louvers & Grilles

VentiMatic™ Shutter Room Exhaust Ventilation

Ventimatic Installation

Storage Cabinets, Sink & Bubbler

Storage Cabinets

Sink & Bubbler Cabinet

End Panels

Filler Sections

Application Considerations

Why Classrooms Overheat

Schools Have Special Needs

Night Setback

Typical Temperature Control Components

Meeting IBC Seismic Requirements

Face & Bypass Temperature Control