McQuay ARQ024 User Manual

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Catalog UV1640

AAF®-HermanNelson® Self-Contained Water Source Heat Pump Unit Ventilator

Standard Range Model ARQ Extended Range Model ERQ Geothermal Range Model GRQ

R-410A Refrigerant, MicroTech II™ (“F” Vintage)

Contents

Introduction

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

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

Model AR, ER & GR Floor Unit ....................................................5

Features & Benets

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

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

Precise Temperature and Dehumidication Control .....................7

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

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

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

MicroTech II Controls

MicroTech II Controls For Superior Performance,

Easy Integration ................................................................... 13-18

MicroTech II Sensors & Control Component Locations ........ 19-21

Accessories

Time Clock ..................................................................................22

Wall Louvers & Grilles ..........................................................22-23

VentiMatic Shutter Room Exhaust Ventilation ...................... 24-25

Storage Cabinets, Sink & Bubbler ........................................ 26-27

End Panels .................................................................................27

Applications Considerations

Why Classrooms Overheat .................................................. 28-31

Meeting IBC Seismic Requirements ...........................................32

ASHRAE Cycle II ........................................................................33

Unit Installation Considerations ............................................ 34-36

Unit Arrangements & Louver Arrangements ......................... 37-44

Unit Selection

Quick Selection Procedure ................................................... 45-48

Selection Procedure ............................................................. 49-50

Engineering Data .................................................................. 51-52

Electrical Data - Size 024 and 040 .............................................51

Electrical Data - Size 048 ...........................................................52

Base Unit Data - AR, ER, GR .....................................................52

Details & Dimensions

Model AR, ER, GR Self Contained Unit Dimensions, 024 ..........53

Model AR, ER, GR Self Contained Unit Dimensions, 040 ..........54

Model AR, ER, GR Self Contained Unit Dimensions, 048 ..........55

End Panels .................................................................................56

Wall Intake Louvers & Grilles .....................................................57

VentiMatic Shutter Assembly ......................................................58

Sink & Bubbler Cabinet & Shelf Storage Cabinets .....................59

Utility Compartment & Filler Sections ........................................60

Wiring Diagrams

MicroTech II Wiring - DX Cooling with Electric Heat, Valve

Control 460Volt / 3-Phase ..........................................................61

Typical Wall Senors ....................................................................62

External Input Wiring ..................................................................62

External Output Wiring-Single Unit .............................................63

External Output Wiring-Multiple Units ........................................63

Guide Specications

AAF-HermanNelson Unit Ventilator Model ARQ, ERQ & GRQ

Guide Specications ............................................................. 64-68

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

U ARQ 6 024 H G 12 Z B1 AL 22 G B B 1

Unit Type

U = Unit Ventilator

Product Identier

ARQ = SC - WSHP 60°F EWT, Standard Range, Ultra Quiet ERQ = SC - WSHP 50°F EWT,

Extended Range, Ultra Quiet GRQ = SC - WSHP 20°F EWT Geothermal Range,

Ultra Quiet

Design Series

6 = F Design

Nominal Capacity, cubic feet/minute (cfm)

024 = 24,000 Btuh 040 = 40,000 Btuh 048 = 48,000 Btuh

Voltage

C = 208-60-1 D = 208-60-3 G = 230-60-1 H = 230-60-3 K = 460-60-3

Cooling Options

G = Direct Expansion (DX) H = Direct Expansion (DX) with refrigerant relief valve

Heating Options

00 = None 12 = Low Electric Heat, 3-element 13 = High Electric Heat, 6-element

Hand Orientation [Right (RH) Left (LH)]

Z = Not applicable

Controls (TC = Time Clock, CO2 = CO2 Sensor)

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 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

Product Styles

Warranty

A = Standard E = Extended X = Special

SKU

B = Standard Delivery

Power Connection

G = Box w/Switch

Return Air

22 = RA Bottom Front / OA Rear Duct Collar 24 = Recirculation RA Bottom Front no RA/OA Dampers

Discharge

AK = 21-7/8" Unit, Top Bar Grille Discharge AL = 16-5/8" Unit, Top Bar Grille Discharge AM = 21-7/8" Unit, Top Bar Grille Discharge, 2" Step AN = 21-7/8" Unit, Top Bar Grille Discharge AP = 21-7/8" Unit, Top Bar Grille, Full Adapter Back AB = 21-7/8" Unit, Top Bar Grille, Full Adapter Back,

Closed Pipe Tunnel w/Solid Back

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/CO LB = Leading Stand-Alone Slave w/o TC w/CO LC = Leading BACnet MS/TP w/o TC w/CO LD = Leading LonMark SCC w/o TC w/CO LE = Leading Metasys N2 Open w/o TC w CO LF = Leading Stand-Alone w/ TC w/CO LG = Leading Stand-Alone Master w/ TC w/CO 44 = Electromech w/2-Pos Damper for Remote T'Stat 45 = Electromech w/2-Pos Damper w/Unit Mtd. ACO 46 = Electromech w/2-Pos Damper w/Unit Mtd. MCO

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 3

Introduction

AAF-HermanNelson Self-Contained Water Source Heat Pump Unit Ventilators

For more than 89 years, schools have relied on AAFHermanNelson unit ventilators to keep classrooms comfortable. Students learn more readily in a quiet, well-ventilated 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 priority for school administrators and school boards. AAF-HermanNelson unit ventilators are inexpensive to install and operate, and they are designed and built to provide decades of trouble-free service.

The ARQ, ERQ and GRQ models are designed and

built for new construction and for retrot commercial and industrial applications such as schools, hospitals, ofce

buildings and other buildings with large conference rooms and common areas. These units contain a built-in refrigeration section that eliminates the need for chillers and outdoor condensing units, making them the right

choice for low- rst cost new or retrot construction.

Quiet Operation

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

Low Operating Costs

When running, AAF-HermanNelson unit ventilators can use as little electricity as two 100-watt light bulbs. They take maximum advantage of “free” cooling opportunities to reduce operating costs. During unoccupied periods and at night, units operate sparingly to conserve energy.

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 eld commissioning. Our

Protocol Selectability feature provides easy, low-cost integration into most building automation systems. Select BACnet®, LonTalk® or Metasys® N2 Open communications to communicate control and monitoring information to your BAS, without the need for costly

gateways. Unit controllers are LONMARK® certied

with the optional LonWorks® communication module.

The Geothermal System (Model GRQ)

Model GRQ Ground Source heat pump utilize the natural properties of the earth to provide heating and cooling to a building. Heat addition and rejection take place below the ground, inside hundreds of feet of high density polyethylene pipe, known as a ground loop. Fluid is circulated through the ground loop and into the geothermal units. The Geothermal heat pump

unit simply amplies and directs conditioned air to the

desired location. In the Heating Mode the earth acts as a heat source,

allowing the circulating uid to extract natural heat from

the earth and transfer it to the space where it can be used for heating.

In the Cooling Mode, the earth acts as a heat sink

enabling the circulating uid to transfer the excess heat,

absorbed by the unit, from the building zones to the earth where it is absorbed and stored for future heating requirements.

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;

scuff resistant nishes and tamper prevention features

on the outside. In fact, many units installed over 30 years ago continue to provide quiet, reliable classroom comfort.

R-410A Refrigerant

4 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Cooling

Cold

Rejection of heat into the ground

Heating

Warm

Addition of warmth from the ground

Introduction

Models ARQ, ERQ & GRQ Water Source Heat Pump Unit Ventilators

1 Welded One-Piece Chassis offers

superior strength, durability, and vibration reduction.

Unique Draw-Thru Design provides

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

Quiet, Aerodynamic Fans utilize

GentleFlo technology for exceptionally quiet unit operation.

4 Modular Fan Section improves

balance, alignment and simplies

maintenance.

5 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.

Model ARQ – Self-Contained - Standard Range WSHP 60°F EWT, Ultra Quiet Model ERQ – Self-Contained - Extended Range WSHP 50°F EWT, Ultra Quiet Model GRQ – Self-Contained - Geothermal Range WSHP 20°F EWT, Ultra Quiet

Available in three sizes, 024 (24,000 Btuh), 040 (40,000 Btuh) and 048 (48,000 Btuh)

7 MicroTech II Controls provide

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

8 Advanced Heat Transfer Coil de-

sign provides extra capacity.

9 Sturdy Cabinet Construction

includes hidden reinforcement, a non-glare textured surface, and a

tough, scuff- and mar-resistant nish

to stand up to the abuses of a classroom environment.

10 Sectionalized Front Access Pan-

els provide easy access to unit inte-

rior. Panels are easily removed by a single person. Front side panels can be removed while unit is running.

11 Two Hinged Top 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-length Air Filter is efcient

and easy to replace. All air deliv-

ered to classroom is ltered.

16 Corrosion Proof Sloped Drain

Pan (Not Shown).

17 Tamper Resistant Fasteners on

Access Panels

Overall Unit Dimensions:

Size 024 – 86" × 30 × 16-5/8" or (21-7/8 with Adapter Back) Size 040 – 98" × 30" × 16-5/8" or (21-7/8" with Adapter Back) Size 048 – 110" × 30" × 16-5/8" or (21-7/8" with Adapter Back)

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 5

Note: Unit size 024 shown (3-fans)

Features and Benets

GentleFlo Delivery

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

• Fan wheels are large, wide and rotate at a low speed to reduce fan sound levels. They are impactresistant and carefully balanced to provide consistent performance.

• Offset, aerodynamic fan wheel blades move air

efciently (Figure 1).

• Precision tolerances help reduce ow and pressure

turbulence, resulting in lower sound levels.

Figure 1: GentleFlo Fan Technology

Expanded Discharge Air Opening

• Fan housings incorporate the latest logarithmic-

expansion technology for smoother, quieter air ow

(Figure 2).

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

• Modular fan construction contributes to equal outlet velocities and promotes quiet operation.

• Fan shafts are of ground and polished steel to mini-

mize deections and provide consistent, long-term

operation.

• Fan assemblies are balanced before unit assembly, then tested after assembly (and rebalanced if necessary) to provide stable, quiet operation.

Offset Aerodynamic Blades

Logrithmic Expansion Housing

Precision T olerances

Figure 2: GentleFlo Reduces Turbulence

High Minimal Turbulence

Offset Aerodynamic Blades

GentleFlo Fan Blade Design Typical Fan Blade Design

Turbulence

6 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Features and Benets

The Right Amount of Fresh Air and Cooling

AAF-HermanNelson unit ventilators deliver required amounts of fresh air to meet ventilation requirements 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 match classroom comfort requirements even more closely, and reduce operating costs.

This means that you can be condent that your school

is 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 efciently deliver outdoor air when

classroom conditions call for “free” or economizer cooling.

With AAF-HermanNelson unit ventilators, you can have outdoor air whenever it is needed. Economizer operation 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 units equipped with MicroTech II controls, three levels of economizer control are available (see See “Economizer Modes” on page 14).

Figure 3: Full Economizer Mode

100% Outdoor Air Into Classroom

Part-Load Variable Air Control

Part Load Variable Air control can be used to automatically adjust the unit ventilator fan speed based upon the room load and the room temperature. This MicroTech II control option provides higher latent cooling capabilities and quieter operation during nonpeak 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 of the fan, which varies according to the room load. It 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.

Precise Temperature and Dehumidication Control

AAF-HermanNelson unit ventilators provide precise

temperature and dehumidication 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 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 more uniform discharge air temperatures into the

classroom and more efcient unit ventilator operation.

Figure 4: Draw-Thru Design Provides Even Discharge Air

Uniform Discharge Air (Shaded)

Motor

Filter

Room Air Damper

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 7

Outdoor Air Damper

Outdoor Air

Fans

Condenser

Features and Benets

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

Coil

Room Air Damper

Room Air

AAF-HermanNelson Draw-Thru Design

Outdoor Air Damper

Outside Air

Filter

RA/OA Divider

Room Air

Outside Air

Blow-Thru Design

Low Installation Costs

Perfect For Both New & Retrot 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 oor-to-oor heights can be reduced,

saving on overall building costs.

Retrot installations are economical because new units typically t the same space occupied by existing ones.

Figure 7: Optional Unit Casters

Left Caster

Counter-clockwise to lower

Clockwise to raise

Casters can be adjusted

Right Caster

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

control conguration.

With MicroTech II controls, you can select BACnet, LonTalk or Metasys N2 communications to communicate control and monitoring information to your BAS, without the need for costly gateways. Unit controllers are LONMARK certied with the optional LonWorks communica- tion module.

Built In Flexibility

AAF-HermanNelson unit ventilators include features that

make them easy to set up and recongure as needed to

meet special requirements. These features include:

• Built-In Wire Race A built-in metal 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 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Features and Benets

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 difcult position: caught between rising costs, lower budgets and the requirements to raise educational standards.

Fortunately, the technology and the system exists for schools to take control of their energy expenditures while 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 unoccupied 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 to 40°F).

• Then consider how AAF-HermanNelson unit ventilators, located 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 classroom for high indoor air quality.

• During most of the school year, they use outdoor air to keep classrooms comfortable without the expense of mechanical cooling.

Figure 8: Energy Savings with Demand Control Ventilation

100%

Energy Savings

with DCV

20%

Unoccupied

DCV's fresh air for indoor air quality

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

School Hours

Cleaning

Unoccupied

After Hours

• Occupancy Mode Operation Units can be pro- grammed 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 low fan speeds which will be at the lower displacement compressor stage. The two stage compressor will remain at low speed until more cooling/ heating is required. With the two-stage 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 oversizing.

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

MicroTech II Control Options Further Reduce Operating Costs

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

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

• Demand Control Ventilation By using CO2 levels to monitor the actual occupancy pattern in a room, the system can allow code-specic levels of outdoor air to be delivered when needed without costly over-ventilation during periods of low or intermittent occupancy (Figure 8).

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 9

Features and Benets

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 closely.

Figure 11: Fan Deck

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 of 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 benet of

extending motor life. Our direct-coupled motor and selfaligning motor mount facilitate motor change-out. The

motor comes with a molex plug that ts all sizes and further simplies removal.

Aerodynamic Fans

Modular Fan Deck

1/4" Mesh Screens Protects Against Objects Dropping into Fan Housings

Heavy-Duty Discharge Grille

Motor Located Out of Airstream

Unit Power On/Off Switch and Wire Trough

10 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Features and Benets

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, targeted access to the component that needs servicing:

• Two end panels provide easy access to piping,

temperature 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.

• Hinged top access doors provide easy access

into the end compartments to facilitate convenient servicing of the motor, electrical, and refrigeration components.

• Center front panel provides easy access to the lter

and the fan shaft bearing on unit size 048.

Filter

Three lter types are offered:

• Units come standard with a single-use lter which is

designed to be used once and discarded.

• Optional, permanent metal lters are available and

can be removed for cleaning and reused numerous times.

• Renewable media lters, which consist of a heavy-

duty, painted-metal structural frame and renewable media.

Figure 13: Easy Access to Filter

Figure 12: Easy Access with Tamper-Resistant Fasteners

Tamper Resistant Fasteners

Removable Filter

Discharge Grille

Tamper Resistant Fasteners

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 11

Features and Benets

Built To Last

Durable, Energy Efcient Fan Motors

AAF-HermanNelson unit ventilators are equipped with 115/60/1 NEMA motors that feature low operating current and wattage (Figure 14).

Figure 14: Energy-Efcient Fan Motor

Energy Efcient NEMA Motor

Decoupled Isolation System

Additional features of these motors include:

• Split-capacitor (PSC) design with automatic reset

and thermal-overload protection.

• No brushes, contacts or centrifugal starting switch-

es – the most common causes of motor failure.

• A built-in, decoupled isolation system to reduce

transmission of vibrations for quieter operation.

• A multi-tap, auto-transformer (Figure 15) provides

multiple fan motor speed control through the speed switch. The motor is independent of supply voltage, which allows stocking of one motor (school districtwide) for various voltage applications.

Figure 15: Multi-Tap Auto-Transformer

Additional features include:

• Outdoor air dampers are made of galvanized steel to inhibit corrosion, with double-wall welded construction for rigidity and encapsulated insulation (Figure 16). Additional insulation is provided on the exterior of the outdoor air damper blade and on the outdoor air entry portion of the unit.

Figure 16: Outdoor Damper Seals Out Cold Weather

Turned Metal Damper Stop

Wool Mohair End Seal

Additional Insulation

Wool Mohair End Seal

Turned Metal Damper Blade

Full-Length Wool Mohair Damper

• Room air dampers are free-oating and designed

to prevent intermittent gusts of cold air from blowing directly into the classroom on windy days (Figure 17). They are constructed of aluminum with built-in rigidity. The metal forming technique that is employed resists twisting and incorporates a fulllength 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 17: 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 16). Positive sealing is provided by embedding the edge into wool mohair (no metal to metal contact). There are no plastic gaskets to become brittle with

time, sag with heat or age, or require a difcult slot t to

seal. Nylon damper bearings foster quiet, maintenancefree operation.

12 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

MicroTech II Controls

MicroTech II Controls For Superior Performance, Easy Integration

AAF-HermanNelson unit ventilators equipped with MicroTech II unit controllers can provide superior performance and easy integration into your building automation system of choice. MicroTech II

benets include:

• Factory integrated and tested controller, sensor,

actuator and unit options promote quick, reliable

start-up and minimize costly eld commissioning.

• High-performance features and advanced control

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.

• For network control applications, our Protocol 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 exibility to

operate AAF-HermanNelson unit ventilators on any of three levels:

• As stand-alone units, with control either at the unit or from a wall sensor.

• In a master-servant relationship, where servant units follow the master unit for some or all functions.

• Controlled as part of a network using a centralized building automation system.

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:

• Automatically by a unit-mounted occupied/unoccupied time clock.

• Automatically by a remote-mounted time clock

Master-Servant Control

Designate the master and servant units and we will

factory congure 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 eld installed).

Servant units can be eld-congured to be dependent or

independent as follows:

• Dependent servant units follow the master unit completely. They are ideal for large spaces that have even loads across the space (such as some libraries).

• Independent servant units (default) use master setpoints and servant sensors. The servant follows the master unit modes, such as heat or cool, but has

the exibility 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 factory-installed options are handled by the unit control-

ler. This simplies the transmission of monitoring and

setpoint data to the building automation system. You select BACnet, LonTalk or Metasys N2 Open

communications to communicate control and monitoring information to your BAS, without the need for costly gateways (see “Optional Communication Modules” on

page 18). Unit controllers are LONMARK certied with

the optional LonWorks communication module. Flexible network communication options via our Proto-

col Selectability feature help you avoid control obsolescence over the life of your AAF-HermanNelson equipment.

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 13

MicroTech II Controls

Control Modes and Functions

AAF-HermanNelson unit ventilators equipped with MicroTech II unit controllers can be programmed to operate in a variety of modes based on the current 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 controls 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 outside air capability and other functions.

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

be congured 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.

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 satised.

The outdoor air damper is closed during this mode.

When a cooling load is satised by a refrigerant system,

the compressor is de-energized and the unit ventilator

indoor fan continues to run for a xed 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 congured to

cycle in response to the load.

Economizer Modes

Economizer operation is facilitated by the outdoor air damper, which automatically adjusts the aboveminimum 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 outside temperatures. If the temperature comparison is satisfactory, then free-air economizer operation is used

to cool the space. Reheat units also come congured

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.

Night Purge Mode

Under this mode, the unit is congured 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.

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 eld congured and/or be disabled.

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 the Unit Ventilator Service Tool or a network.

14 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

MicroTech II Controls

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 pro-

vided with conguration 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 Ventilator Controller.

Unoccupied Input Signal

This input signals the unit ventilator controller to go into unoccupied or occupied mode. When the contacts 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.

Remote Shutdown Input Signal

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

vided with conguration 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 Unit 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).

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.

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 dened 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.

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, the 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 congured 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 Conguration variable can be used

to set the controller to use an NC auxiliary heat device (energize when heat is required) such as electric heat.

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 15

MicroTech II Controls

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 comfortable classrooms, as described below.

Part Load Variable Air Control

Part Load Variable Air control can be used to automatically adjust the unit ventilator fan speed based 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 on low speed. When the load 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. Lowspeed 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 CO2 controller to ventilate the space

based on actual occupancy instead of a xed design

occupancy. This Demand Controlled Ventilation (DCV) system monitors the amount of CO2 produced by students and teachers so that enough fresh outdoor 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 occupancy pattern

in a room, the system can allow code-specic levels of

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

With DCV you can be condent that your school is

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, in between classes, or after hours when classrooms are heated and cooled but not always fully occupied.

Acceptance by Codes and Standards

ASHRAE Standard 62-2004 Ventilation for Indoor Air Quality recognizes CO2 based DCV as a means of 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 CO2 control will sometimes lower the absolute 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 × 15 cfm/student). However, when there are only ten students in the classroom, the CO2 control will adjust ventilation to 150 cfm (10 students × 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.

DX System Control

The unit ventilator controller is congured 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 dened

operating envelope.

Compressor Cooling Lockout:

The unit ventilator controller is congured 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 minimumon and minimum-off timers to prevent adverse compressor cycling (3-minutes default).

16 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

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 addition, unit ventilators equipped with MicroTech II controllers feature factory-mounted sensors and 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-specic

component shutdown if critical system conditions occur. Each UVC is factory wired, factory programmed and

factory run-tested for the specic unit ventilator model and conguration ordered by the customer.

Figure 18: MicroTech II Control Board

Terminal Connections Plug-In Control Module

Figure 19: User Interface Touch 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 states can be chosen on the LUI:

Heat: Heating and economizer operation only. Cool: Cooling and economizer operation only. Fan Only: Fan only operation. Auto: The unit automatically switches between heating,

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

Local User Interface

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

• The room set point temperature.

• The current room temperature.

• Any fault code for quick diagnostics at the unit.

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 a standard, single-speed NEMA frame motor. A built-in 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 fan automatically shifts to the medium speed setting. At near-design or design-load conditions the fan will operate on high speed.

With four fan states and GentleFlo fan technology, there is no need to oversize units or worry about uncomfortable conditions.

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 17

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 20: 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) prole number 8500-10. Unit

controllers are LonMark certied with this optional LON-

WORKS communication module.

Figure 21: 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

congured to use a 0-100% RH, 0 VDC, capacitive

humidity sensor. Humidity sensors are available as unitmounted only. The humidity sensors are used with units using an outdoor enthalpy economizer or an indoor/ outdoor enthalpy economizer.

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 congured to use passive Positive Temperature Coefcient (PTC) unit-mounted and

wall-mounted sensors. These sensors vary their input resistance to the UVC as the sensed temperature changes.

CO2 Sensor for Demand Controlled Ventilation

On units equipped for Demand Controlled Ventilation

(DCV) the UVC is congured to use a 0-2000 PPM,

0-10 VDC, single beam absorption infrared gas sensor. CO2 sensors are available as unit mounted only. An air

collection probe (pitot tube and lter) is installed in the

return air of the unit.

Figure 22: CO2 Sensor For Demand Control Ventilation

Remote Wall-Mounted Temperature Sensors

MicroTech II unit ventilators offer two choices for remote wall-mounted room sensors (Figure 21). Each has a tenant override capability and comes with an international, quick-fastening connection capability.

18 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

MicroTech II Controls

MicroTech II Sensors and Component Locations

Figure 23: 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 Standalone unit control, Master/Servant control or incorporated into a building-wide network using an optional plug-in communication module. The UVC contains a microprocessor that is preprogrammed with the application code required to operate the unit. The UVC supports up to 6 analog inputs, 12 binary inputs, and 9 binary outputs. The UVC EXP I/O board supports up to 4 additional analog

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 19

inputs and 8 additional binary outputs. Master/Ser-

vant units have the controller factory congured and

installed for a local peer-to-peer network between these units (network wiring between these units needs to be eld installed). Optional network communication is provided via plug-in communication modules that connect directly to the UVC.

2. Communication Module (optional): Plug-in network communication module that is attached to the UVC via a 12-pin header and 4 locking standoffs. Available communication modules:

MicroTech II Controls

• Building Automation and Control Network (BACnet®) Master Servant/Token Passing (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/ ASHRAE 135-1995 standard for BACnet systems.

• LonWorks® compliant Space Comfort Controller (SCC) – Supports the LonWorks SCC prole number 8500_10.

• Metasys N2® Open – Provides N2 Open network 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. See “Local User Interface” for further details.

4. Tenant Override Switch: Provides a momentary contact closure that causes the unit to enter the “tenant override” operating mode for a set time period (default = 120 minutes).

5. Time Clock (TC) (optional on standalone units only): Factory mounted 7 day/24 hour, digital time

clock with up to twenty (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: Three (3) multi-pin plugs are factory provided and pre-wired with short wire whips that are capped (they must remain capped if not used).

Provided for eld wiring of :

• Remote Wall Mounted Temperature Sensor (op-

tional accessory).

• External Input Signals (by others): unoccupied, remote shutdown, ventilation lockout, dew point/ humidity (night time operation), or exhaust interlock signals

• External Output Options (by others): lights on/off, fault indication signal, exhaust fan on/off or auxiliary heat signal.

7. Motor Speed Transformer: (Located beneath the Local User Interface Panel). Multi-tap auto-transformer provides multiple fan motor speed control through the LUI.

8. Unit Main Power “On-Off” Switch (SW1): Disconnects the main power to the unit for servicing or when the unit is to be shut down for an extended period of time.

Figure 24: Unit Main Power “On-Off” Switch (SW1)

9. Fuse(s): Fan motor and controls have the hot line(s) protected by factory installed cartridge type fuse(s).

10. Control Transformer: 75 VA 24-volt NEC Class 2 transformer for 24 volt power supply. (Located behind the motor transformer).

11. Outdoor Air/Return Air Damper Actuator (A1):

Direct coupled, oating point (tristate) actuator that

spring returns the outdoor air damper to the closed position upon a loss of power.

12. Low Refrigerant Temperature Sensor (S4): The S4 sensor is provided on all units with a direct expansion (DX) cooling coil. It is located on the right hand side of the air coil “u-bend”.

13. Room Temperature Sensor (S1): The 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 also available for remote room temperature sensing. (optional accessory).

14. Discharge Air Temperature Sensor (S2): The sensor is located on the second fan from the right to sense discharge air temperatures.

20 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

MicroTech II Controls

15. Outdoor Air Temperature Sensor (S3): The sen-

sor 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.

16. Outdoor Air Humidity Sensor (S8) (optional): Unit mounted humidity sensor for units using Expanded outdoor enthalpy economizer or Leading Edge indoor/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.

17. Room Humidity Sensor (S6) (optional): Unit mounted humidity sensor for units capable of active

dehumidication 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 through the network.

18. CO2 Sensor (S7) (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 remote sensor through the network.

19. Water Out Temperature Sensor (S9): The water out temperature sensor is factory wired. The sensor

must be eld-installed and insulated (by others) and

located on the return connection of the plate heat exchanger.

20. Water Coil DX Temperature Sensor (S5): The S5 sensor is factory wired, installed and insulated. It is located on the lower left refrigerant line of the plate heat exchanger leading to the expansion valve.

Figure 25: Water Out & Water Coil DX Temperature Sensors

Actuators

Outdoor Air/Return Air Damper (OAD) Actuator

The UVC is congured to operate a oating-point (tri-

state) 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, congurable setting for each

actuator's stroke time.

Figure 26: Outdoor Air Damper Actuator

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 21

Accessories

Optional Time Clock for Stand-Alone Units

As an option, stand-alone, non-servant unit ventilators can be factory-equipped with a unit-mounted, digital, 24-hour/7-day time clock with 20 programs (Figure 27). The clock is factory-wired to automatically place the unit into occupied or unoccupied mode based upon its schedule. Features of this clock include:

• Large keys with circular programming for easy

schedule setup

• An LCD display

• Manual 3-way override (On/Auto/Off)

• Capacitor backup to retain program memory during

power outages.

Figure 27: Optional Time Clock

ServiceTools comes with a service cable having two interface connections:

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

• A 3-pin connection to the optional communication

modules.

Wall Louvers & Grilles

AAF-HermanNelson wall louvers allow outdoor air to be drawn in while blending with the building architecture. They are sized to match the unit outside air opening and provide maximum air intake. Heavy-gauge, all aluminum construction is standard, with a decorative grille optional.

Both louvers and grilles are available either painted or unpainted. When painted, a specially formulated, environmentally friendly thermosetting urethane powder is applied electrostatically and baked for long lasting beauty as well as resistance to corrosion. The paint is then oven cured to provide correct chemical crosslinking, which can provide years of service. The alloy used for louvers and grilles, AQ 5005, is suitable for color anodizing by others.

ServiceTools™

ServiceTools for MicroTech 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:

• Monitor equipment operation.

• Congure network communications.

• Diagnose unit operating problems.

• Download application code and congure the unit.

This software is a purchased tool for service technicians and will run on PCs with Windows® 98 (Second Edition), 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 requirements.) It has no BAS functions, such as scheduling or trending, and it cannot serve as a Work Station Monitoring package.

Figure 28: Intake Louvers

Horizontal Blade Louver

Vertical Blade Louver

22 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Accessories

passages maximizing

Louver Details

Louvers are available in both horizontal and vertical

blade congurations (Figure 28):

• Horizontal blade construction turns the incoming air to keep moisture from entering. Bottom weep holes drain moisture to the outside.

• Vertical-blade construction provides positive water impingement and entrapment. The bottom lip drains moisture to the outside.

Louvers can be supplied with or without anges:

• Flanged louvers are typically used for a panel wall

nish (Figure 29).

• Unanged louvers are typically used for recessing into a masonry wall.

Figure 29: Flanged Louver (Indoor View)

Figure 31: Horizontal Louver with Decorative Intake Grille Detail

Square lattice grille openings align with the louver blade air passages maximizing the air opening

Optional Grille

Turned edge along the exterior and interior blade edge reduce visibility into the interior, adds rigidity to louver

Bird Screen

A half-inch-square mesh bird screen (Figure 29) located on the leaving air side of the louver prevents birds and other small animals from entering. The screen’s strong aluminum mesh is designed to minimize air pressure drops, unlike expanded metal mesh.

Grille Details

AAF-HermanNelson decorative intake grilles come in either painted or unpainted AQ 5005 aluminum with holes for mounting to building exteriors (Figure 30). Their square holes are designed to match the blades of the AAF-HermanNelson louver, maximizing the air opening.

Figure 30: Horizontal Louver with Decorative Intake Grille

Weep Holes

Figure 32: Vertical Louver with Decorative Intake Grille Detail

Turned edge on louver blade entering and leaving surface reduce the visibility of the outdoor coil and fan section. Adds rigidity to louver.

Louver Blade

Square lattice grille openings align with the louver blade air

the air openings

Optional

Heavy-Duty

Lattice Grille

Optional

Louver Flange

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 23

Accessories

VentiMatic™ Shutter Room Exhaust Ventilation

Outdoor air introduced by the unit ventilator must leave the room in some way. In some states, exhaust vents 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-actuated room exhaust vent (Figure 33). It operates in direct response to positive static air pressure created when ventilation air is brought into the room by the unit ventilator. It is a “one-way”

shutter that opposes any ow of air into the room.

Figure 33: VentiMatic Shutter

Back (Outdoor Side) Front (Indoor Side)

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 Shutter operation is inherently silent. Unlike other non-powered vents, it opens at an extremely low positive pressure (0.005").

Its shutter aps are made of temperature-resistant glass fabric impregnated with silicone rubber for exibility and

long life. This fabric retains its original properties down to -50°F.

VentiMatic Installation Considerations

Figure 34: VentiMatic Shutter Components

Louver ships assembled as one piece

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 press

air ow that could occur with opposite-wall mounting.

The VentiMatic Shutter is generally mounted on an AAFHermanNelson wall louver (ordered separately) which is then used for exhaust (Figure 34). For large unit ventilators, two Ventimatic Shutters may be mounted side by side on the same wall louver to adequately promote 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 integrating the VentiMatic Shutter 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-inch-length wall louver can be accommodated behind a 4-foot-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 combina-

tion will enable a complete, integrated, energy-efcient

HVAC and room exhaust system

Note: Storage cabinets are provided by others. Contact

your McQuay sales representative for options.

24 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Accessories

Figure 35: VentiMatic Shutter Installation

Louver

VentiMatic Shutter

Steel Shutter Mounting Plate

The VentiMatic shutter assembly mounts on the same wall as the unit ventilator louver, to neutralize wind effect.

Outside

Roomside

Building Wall

Closed Shelf Storage Cabinet with Slotted Kickplate

Outside

Exhaust Air

VentiMatic & Louver Assembly behind cabinet.

Flexible Glass Fabric, Silicone-Impregnated Shutter Leaf

Steel Bafe

Leaf Support

Cabinet Slotted Kickplate

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 25

Accessories

Storage Cabinets, Sink & Bubbler

Note: Storage Cabinets, Sink & Bubbler are provided by

others. Contact your McQuay sales representative for options.

AAF-HermanNelson storage cabinets are designed to complement our classroom unit ventilators. They are made from furniture-quality, cold-rolled steel and reinforced for additional strength to withstand the abuse of

a classroom environment. Cabinets are nished with a

durable epoxy powder coating to withstand marring and scratches.

Storage Cabinets

Shelving cabinets feature epoxy powder coated steel tops of charcoal bronze color or laminated tops.

• Available in 4 lengths: 24", 36", 48" and 60", in open cabinets or with sliding doors with bottom glide track for good alignment

• Optional door locks available

• 4 heavy-duty leveling legs that allow for 3/4" of verti-

cal adjustment

Sink & Bubbler Cabinet

Sink & bubbler cabinets have a one-piece 18-gauge

stainless steel top with a satin-brushed nish, a raised

front lip, and formed back and end splash boards.

• Available in 2 depths for models AR, ER and GR; 16-5/8" and 21-7/8"

• Underside of top is fully coated to minimize noise and condensation

• Epoxy powder coated to match the Unit Ventilator and other cabinets

• Bubbler Bowl provided as option

Figure 36: Typical Unit Ventilator Install with Storage Cabinets Application

Self-Contained Unit Ventilator

A Storage Cabinet, with doors B Corner Filler Section

C Storage Cabinet with shelves, without doors D Sink and Bubbler, with doors E Utility Compartment F 1" End Panel

26 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Accessories

Utility Compartments

Note: Utility Compartments are provided by others.

Contact your McQuay sales representative for options.

Utility Compartments can be used as spacing between cabinets or walls and to provide added service access.

• Available in standard lengths of 18" and 24"

• Epoxy powder coated steel tops of Charcoal Bronze

paint or laminated top

Figure 37: Utility Compartment

Utility Compartment - Textured Top

Figure 38: 1" End Panel

1/4"- 20 Tinnerman Nut, Clip over Lower Hole in Unit Base

Figure 39: 6" End Panel

1/4"- 20 × 1/2" Screw

Tinnerman Nut, Clip on End Panel

1" End Panel

1/4"- 20 × 1/2" Screw

End Panels

One-inch end panels are typically used to nish off stand-alone oor units (Figure 38). Six-inch end

panels with kick plates can be used to provide extra space needed for piping (Figure 39). All end panels are individually wrapped in plastic and boxed to help prevent damage during construction.

6" End Panel

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 27

Application Considerations

Possible Heat Gain From

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, resulting in excessive operating costs.

Correcting an overheating problem in an existing

building is very difcult and expensive. It calls for

redesign and 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, ve 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

must rst realize that the excess heat comes from what

is commonly termed “uncontrolled heat sources.” To gain some perspective on how this affects heating and cooling 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 window area 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 amount of heat that the room loses. This is represented in Figure 40 by Room Heat Loss Line A, which ranges from 55,000 BTU per hour at 0°F outside air temperature to zero BTU at 70°F. Obviously, if the

Figure 40: Heat Gain vs. Heat Loss In Occupied

60,000

50,000

40,000

30,000

20,000

Room Heat Loss, BTU/HR

10,000

-10 010203040506070

ROOM HEAT LOSS LINES

Outside Air Temperature, °F

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

10,000 BTU/HR

}

Sun, Direct & Reflected

8,500 BTU/HR

}

Heat Gain From Lights

7,800 BTU/HR

}

Heat Gain From Students

Note: As this chart illustrates, even in very cold weather

an occupied classroom is more likely to require cooling than heating.

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 40 as “Heat Gain from Students.”

Heat Gain From Lights

Heat emitted by the lighting system constitutes a

second uncontrolled heat source. Articial 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 total of 8,500 BTU per hour. This extra heat is represented in Figure 40 as “Heat Gain from Lights.”

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

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.

28 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

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 difcult. Solar

heat gain can be the worst offender of the three in

classrooms with large windows. Indirect or reected

Application Considerations

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 assume that the solar heat gain in our hypothetical 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 40 by the top horizontal line, which intersects Room Heat Loss Line A at approximately 37°F. This is a reasonable estimate of the maximum uncontrolled heat gain that can be received in the typical classroom from these common heat sources.

The Analysis

From Figure 40 it is evident that, at an outside temperature of 48°F or higher, the heat given off by

30 students and classroom lighting is sufcient 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 approximately 33°F in the region where our typical 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 a room heat loss of 55,000 BTU/HR at a design outdoor air temperature of 0°F (Room Heat Loss Line “A”). Bear in mind, however, that the recent trend in “energysaving” 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:

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

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

• Room “D” has a room heat loss of 25,000 BTU/HR

Note: The lowering of the temperature above which

cooling will always be required as the room heat loss decreases.

We’ve noted that cooling is always required in Classroom “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 40).

Now that we understand the reason for classrooms overheating, the solution is simple: The heating and ventilating system must provide cooling to take care of the heat given off in the classroom by uncontrolled heat sources.

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 temperature is nearly always below the desired room temperature. It stands to reason then that the outside air should be used to provide the cooling necessary to keep classrooms down to thermostat temperature.

The classroom unit ventilator does just that. By incorporating an automatically controlled outdoor air damper, a variable quantity of outdoor 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 specied along

with the heating capacity required. If this is done, the optimum learning temperature can be maintained in each classroom.

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 windows and 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.

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 29

Application Considerations

For this reason, the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) now recommends 15 cfm of outdoor air per pupil, and no longer endorses the practice of little or no usage of outdoor air.

It should be kept in mind that a properly designed exhaust system is essential for avoiding indoor air quality 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 shutter, a gravity-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

inltration of undesirable gases into the classroom. See

“VentiMatic™ Shutter Room Exhaust Ventilation” on page 24.

Following ASHRAE Control Cycle II

ASHRAE Cycle II is a very economical sequence of control because only minimum amounts of outdoor 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 controlled according to ASHRAE Control Cycle II. 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 33.)

Under ASHRAE Cycle II, the outdoor air damper is closed during warmup of the room. As the room temperature approaches the thermostat setting, the outdoor air damper opens to a predetermined minimum 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, the heating coil is turned off and the outdoor air damper opens beyond the minimum position to maintain the thermostat setting.

EXAMPLE: For a 60°F entering air mixture temperature 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.

Night Setback

Substantial fuel savings can be realized by operating the unit ventilator system at a reduced room setting at night and during other unoccupied periods, such as weekends and holidays. 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

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.

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 outdoor 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.

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.

30 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Application Considerations

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.

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.

DX Cooling Low Ambient Lockout:

This lockout must be used on DX 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 cooling units to deenergize the 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.

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/heating capacity in the medium and low fan speed will allow the system to run longer at moderate and low load conditions providing better humidity control. When the high capacity is needed the high speed will provide high compression and full capacity cooling/heating.

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 n tube coil that results in reduced heat transfer. The

constant movement of the electric heating cal rod within the tube shortens life.)

Coil Selection

All coils have their own unshared n surfaces (some manufacturers use a continuous n surface, sacricing proper heat transfer). The result is maximum efciency

of heat transfer, which promotes comfort and reduces operating costs.

An air break between coils in all AAF-HermanNelson units is used to enhance decoupling of heat transfer surfaces—providing full capacity output, comfort and reduced operating costs.

Direct expansion (DX) coils are constructed of

aluminum ns with a formed, integral spacing collar. The ns 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.

Meeting AHRI 840 Requirements

AAF-HermanNelson unit ventilators are rated per AHRI 840. Per this standard, unit ventilators with outside air ventilation and return air dampers must provide ventilation air at a rate of minimum of 80%

rated standard air ow. They must also be capable

of providing any combination of humidity control,

circulation, heating or cooling, and ltering of air.

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 31

Application Considerations

(4) - 3/8" diam. x (dimension “Y”) galvanized threaded rod (by others) - align with unit mounting holes, and set into building structure mortar or structural support column (see detail).

(4) - 1-1/2" O.D. x (dimension “X”), galvanized steel pipe (by others), gives rigidity to the unit in relation with the building structure (see detail).

(4) - 3/8" galvanized nut with washer (by others), attach from inside unit end compartments. Tighten nut until steel pipe is compressed between unit and building structure or column.

Lintel (by others)

Building structure or support column

Gasket on back of unit

Top mounting hole on unit frame

1-1/2" O.D. galvanized steel pipe

DETAIL

Meeting IBC Seismic Requirements

AAF-HermanNelson unit ventilators can be specied,

as follows, to meet International Building Code seismic requirements:

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

rated and certied to meet the seismic compliance

standards of the International Building Code.

• Components designated for use in systems that are life safety, toxic, high hazard, combustible or am-

mable meet the on line, anchorage and load path requirements for life safety as dened 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 components used as part of a system other than the above meet as a minimum, all load path and anchorage standards for components as outlined in IBC section 1621.3.3 & 1707.7.2.

• All completed component assemblies are clearly labeled for eld inspection. Seismic Compliance Labels include the manufacturer's identication, designation of certied models, denitive information

describing the product's compliance characteristics, and the Independent Certifying Agency's name and

report identication.

Figure 41: Typical IBC Seismic Installation

In addition to all seismic requirements for IBC

Certication listed elsewhere in the project specication,

submittals for these units include:

1. A Certicate of Compliance from the Independent Certifying Agency clearly indicating that components supplied on this project are included in the compo-

nent manufacturer's Certicate of Compliance.

2. Clear installation instructions including all accessory components that are part of the overall component installation.

Note: Dimensions “X” and “Y” to be determined by

installing contractor based on t-up requirements

of job.

*A Molly or Toggle bolt may be necessary if voids

in the building structure or support columns are present.

32 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

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:

During warm-up (any classroom temperature 3°F or more below heating setpoint), the outdoor air damper is closed and the unit conditions only room air. As room temperature approaches the heating setpoint the outdoor 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 position to provide economizer cooling.

ASHRAE Cycle II requires that a minimum of three temperature measurements be made:

Figure 42: ASHRAE Cycle II Operation

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

The control sequence should incorporate a Discharge 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, the discharge-air low-limit function will disable cooling (if 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 rst stage

of cooling, and when to use mechanical or hydronic

cooling as the rst 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 damper 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 capability is closed (or off). F Heating begins to modulate (or on). G Heating capability has reached 100%.

Typical Mechanical Cooling Operation

H Mechanical cooling (DX) is closed (or off). J Mechanical cooling (DX) has reached 100%.

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 33

Application Considerations

Unit Installation

The oor unit ventilator is typically applied exposed on

an outside wall below a window in the classroom. This allows fresh air (outdoor air) to be directly fed into the

classroom after ltering or tempering. The oor unit is usually mounted ush against the wall with the fresh air

opening in the back and the return air opening in the front. All units have a fully insulated back with gasketing for added protection.

Wall and Floor Considerations

It is critical to consider the oor and wall structures when installing oor-mounted unit ventilators. The

following requirements apply:

• The unit must be securely mounted against an outside wall into which an opening is cut for an outdoor air intake louver.

• Placement of the outdoor air intake louver is critical for proper ventilation. It must be unobstructed, with no plants, trees or walls blocking the opening within 3 feet.

• Four pre-drilled holes are provided for securing the unit to the wall. Structural members must be available in the wall to support these attachments. Securing the unit to the wall compresses the unit back insulation and gasketing to help prevent air leaks and freezing of piping or coils.

• The oor must have sufcient strength to support

the unit and prevent tipping.

• Space must be available under the oor to feed piping supply and return lines to the unit.

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

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, nish 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 toward the intake opening to a point 1" above the

nished base of the unit.

If a metal sleeve connection is to be used between the unit ventilator and the wall louver, this sleeve must be installed after the unit ventilator is set, making a weather-tight connection to the unit ventilator cabinet. Turn the sleeve over the edge of the louver frame by

proper peening before the louver is nally installed.

Figure 43: Typical Wall Opening with Lintels

Outdoor Side

Bottom of Intake Opening Sloped Down T oward Louver

Indoor Side

Top, Sides and Bottom on Inside of Opening Finished Smooth with Mortar

Lintel (by others)

34 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Application Considerations

Figure 44: Typical Classroom Unit Ventilator Installation and Louver Details

Internal Column for Wall Bracing (By Others)

Lintel (by others)

Weep Holes

Screws or Bolts (by others)

Refrigerant Pipe Tunnel

Unit Gasket

1" End Panel w/Cut Out

Caulk T op and Two Sides of Louver

Sealed Mortar Bed

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 least 1/2" below the level of the inlet to the unit ventilator.

However, if a high intake opening is necessary, the top of this opening should be not more than 28" above the surface upon which the unit ventilator will set.

Recessed Wall Louvers

Set recessed wall louvers into the wall in a bed of mortar with the face of the louver frame set slightly inside the wall line. The complete wall louver frame must be level with the face plumb and the louver frame set so that the drain holes on the bottom are toward the outside of the building.

Unit Insulating Blanket

Caulk

Weep Holes

Bird Screen

Floor

Back of Unit

Unit Outside Air Opening

Unit Bottom Gasket

Seal Under Unit

The mortar should seal the frame perimeter water-tight to help prevent leaks. Do not block drain holes in the frame with mortar (Figure 45).

Figure 45: Recessed Wall Louver Installation Detail

Lintel (by others)

Louver Blades

Bird Screen Cement Mortar

Pitched Away from Unit T oward Louver

Drain Holes (Do Not Block with Mortar or Caulk)

1" Minimum

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 35

Application Considerations

Flanged Wall Louvers

Set anged wall louvers into the wall in a bed of mortar with the face of the louver frame ush with the wall line

(Figure 46). The complete wall louver and frame must be set level. Do not block drain holes in the frame with mortar.

Figure 46: Flanged Wall Louver Installation Detail

Caulk - 4 Sides

Louver Blades

Drain Holes (Do Not Block with Mortar or Caulk)

Flange - 4 Sides

Lintel (by others)

Bird Screen Cement Mortar

Pitched Away from Unit T oward Louver

1" Minimum

Use appropriate fasteners to secure the louver through

the ange into the adjacent wall. Caulk the entire perimeter of the ange. For panel wall construction

applications, caulk and seal the top and vertical sides of the vertical blade louver. Be sure that the drainage holes are pointing outward and that a metal channel is used to drain moisture (Figure 47).

Figure 47: Panel Wall Louver Installation Detail

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 drafts and potentially freeze coils.

Be certain that no gap is left between the unit and the outside air louver opening. Otherwise, outside air can leak into the room.

A rubberized, self-adhering membrane around the outside air opening can be used to seal any air or water leaks that might result from construction. Provide a seal

under the unit to prevent air inltration. In addition, seal

the unit top and side perimeters to prevent unnecessary

air inltration 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 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 oor 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 is a more economical solution to the problem. See “Ventimatic™ Shutter Room Exhaust Ventilation” on page 24 for information on this system and its proper installation.

Caulking

Weep Holes

Metal Channel (Not Furnished)

36 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Application Considerations

Unit Arrangements: 16-5/8" Deep

Arrangement AL – Open Refrigerant Pipe Tunnel

Arrangement AL units are 16-5/8” deep. They are available as open refrigerant piping (Figure 48) and closed refrigerant piping (Figure 49). These arrangements are most often used when there is a chased wall for water supply and return piping. Choose closed refrigerant piping arrangement when the

refrigerant piping tunnel will be open to air ow along

the back of the unit.

Figure 48: 16⅝" Arrangement AL with Open Refrigerant Piping

Open Refrigerant Pipe Tunnel

Chased Wall Unit Installation with Floor-Level Outdoor Air Intake:

Unit Refrigerant Piping

Lintel (By Others)

Louver

Sealed Cement Mortar;

Pitch Away

From Unit

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 37

1" (25mm)

Important: Gasket sealing surface is required.

Floor Line

Chased Wall Unit Installation with Above-Floor-Level Outdoor Air Intake:

Top of intake louver up to 21" (533mm) above oor.

(With adapter back available as an accessory)

Lintel (By Others)

Louver

Not Less Than 3" (76mm)

Not More Than 21" (533mm)

Sealed Cement Mortar; Pitch Away From Unit Provide Drainage

Unit Refrigerant Piping

1" (25mm)

Important: Gasket sealing surface is required.

Floor Line

Application Considerations

Arrangement AL – Closed Refrigerant Pipe Tunnel

Figure 49: 16⅝" Arrangement AL Closed Refrigerant Pipe Tunnel

Closed Refrigerant Pipe Tunnel

Chased Wall Unit Installation with Floor-Level Outdoor Air Intake:

Extra wall space is used to deliver fresh air to the unit outdoor opening. When a chased wall is used, pipes

and n tube radiation can be run inside the chased wall. The back of the accessory must be eld-installed.

Lintel (By Others)

Insulated Closure Plate Accessory

Intake Louver

Not Less Than 3"

Not More Than 28"

Sealed Cement

Pitch Away

Mortar; From Unit

Provide Drainage

Unit Refrigerant Piping

1" (25mm)

Important: Gasket sealing surface is required.

Floor Line

Chased Wall Unit Installation with Window Below Unit Top:

This installation allows window sills below the

standard 30" unit height to project a nished image

from outside. It also allows fresh air to be placed directly opposite the unit outside air opening. A 9" painted, insulated plate accessory encloses the pipe tunnel on the back of the unit.

Painted, Insulated Closure Plate Accessory

Sash

Lintel (By Others)

Intake Louver

Sealed Cement

Pitch Away

Mortar; From Unit

Unit Refrigerant Piping

1" (25mm)

Important: Gasket sealing surface is required.

Floor Line

38 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Application Considerations

Unit Arrangements: 21-7/8" Deep

Arrangement AL with A-Back Accessory Top

Figure 50: 21⅞" Arrangement AL with Accessory Top

Installation with Insulated Accessory Top:

Allows for wall or piping considerations using eld-

installed duct (by others) to unit outdoor air.

Insulated, Texture-Painted Accessory T op

Field-Provided Piping

Lintel (By Others)

Intake Louver

Sealed Cement

Pitch Away

Mortar; From Unit

21-7/8"

Field-Fabricated, Insulated Duct to Unit Outside Air Inlet

1" (25mm)

Important: Gasket sealing surface is required.

Floor Line

Accessory T op

Accessory Top with 2" Painted Step Down

Installation with 2" Finished Stepdown Accessory Top:

This installation allows window sills below the

standard 30" unit height to project a nished image

from outside while allowing for piping considerations using insulated duct (by others) to unit outdoor air inlet.

Insulated, T exture-Painted Accessory T op

Sash

Lintel (By Others)

Intake Louver

(25mm) Not More Than 12"

21-7/8"

Field-Provided Water Piping

Field-Fabricated, Insulated Duct to Unit Outside Air Inlet

Floor Line

Sealed Cement

Pitch Away

Mortar; From Unit

Important: Gasket sealing surface is required.

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 39

Application Considerations

Arrangement AK

The AK arrangement has a partial adapter back with the refrigerant piping open and a rear outdoor inlet.

Figure 51: 21⅞" Arrangement AK

Open Refrigerant Piping

Installation with Floor-Level Outdoor Air Intake:

This installation provides extra space for piping. Fresh air is directlty opposite the unit outside air opening. The unit back and outdoor enclosure are insulated.

Gasket Seal

Unit Refrigerant Piping

Lintel (By Others)

Field Supplied Water Piping

Intake Louver

Not More Than 12"

Sealed Cement

Pitch Away

Mortar; From Unit

1" (25mm)

Important: Gasket sealing surface is required.

Floor Line

40 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Application Considerations

Arrangement AM

The AM arrangement has a full adapter back with the

refrigerant piping closed and a 2" painted nish step

down for a lower height window and sash application.

Figure 52: 21⅞" Arrangement

Closed Refrigerant Pipe Tunnel

Installation with 2" Finished Stepdown Top:

This installation allows window sills below the

standard 30" unit height to project a nished image

from outside. Allows fresh air to enter 27" from the

oor to compensate for conditions that can arise

during renovation or new construction.

Insulated, T exture-Painted Top

Sash

Lintel (By Others)

Intake Louver

Not More Than 12"

Sealed Cement

Pitch Away

Mortar; From Unit

21-7/8"

Field-Provided Water Piping

1" (25mm)

Floor Line

Important: Gasket sealing surface is required.

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 41

Application Considerations

Arrangement AN

The AN arrangement has a full adapter back with the refrigerant piping closed and a rear outdoor air inlet.

Figure 53: 21⅞" Arrangement AN

Closed Refrigerant Piping

Installation with Floor-Level Outdoor Air Intake:

Fresh air is directly opposite the unit outside air opening. Piping can be run through the insulated, closed piping tunnel. Unit top, back and vertical adapter back partitions are insulated.

Unit Refrigerant Piping

Lintel (By Others)

Field Supplied Water Piping

Louver

Sealed Cement

Pitch Away

Mortar; From Unit

1" (25mm)

Important: Gasket sealing surface is required.

Floor Line

Installation with Above-Floor Outdoor Air intake:

Allows fresh air to enter from just below the top of the unit to the bottom. Thus, architectural and snow considerations can be accommodated.

Lintel (By Others)

Unit Refrigerant Piping

Louver

Sealed Cement Mortar; Pitch Away From Unit

Not More Than 28"(711mm)

Field Supplied Water Piping

Floor Line

Important: Gasket sealing surface is required.

42 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Application Considerations

Arrangement AP

The AP arrangement has a full adapter back with the refrigerant pipe tunnel closed and an outdoor air duct collar inlet.

Figure 54: 21⅞" Arrangement AP

Closed Refrigerant Pipe Tunnel

Installation with Floor-Level Outdoor Air Intake:

Allows fresh air to enter from the top of the unit from window intake situations that can arise during renovation or new construction.

Window Sash

Goose Neck Insulated Duct (by others)

Louver

Duct Collar (by AAF)

Unit Refrigerant Piping

Field Supplied Water Piping

Floor Line

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 43

Application Considerations Arrangement AB

The AB arrangement has a full metal back cover that allows cutting a direct fresh air connection to the outside air opening when desired. The unit top, back vertical adapter back partitions and center inside metal back are insulated.

Figure 55: 21⅞" Arrangement AB

Closed Pipe Tunnel

Installation with Floor-to-Top Outdoor Air intake:

Lintel (By Others)

Unit Refrigerant Piping

Louver

Sealed Cement Mortar; Pitch Away From Unit

Not More Than 28"(711mm)

Field Supplied Water Piping

Floor Line

Important: Gasket sealing surface is required.

44 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Unit Selection

Quick Selection Procedure

The following procedure will provide you with a rough determination of unit capacity for cooling and/ or heating based on the number of coil rows. Use

capacity tables for nal selection. Consult your local

AAF-HermanNelson representative for details on the computer selection programs McQuay International provides for this purpose

Water Loop – Cooling (Models ARQ, ERQ)

Table 1: Standard ISO Water Loop Cooling at High Indoor Fan Speed

Total Cooling Capacity Sensible Capacity Waterow Efciency Power Nominal Airow Unit Size Btuh Watts Btuh Watts GPM EER Watts CFM L/S

024 23000 6740 17600 5160 6.5 13.0 1770 1000 472 040 39200 11490 28000 8210 10.0 13.5 2905 1250 590 048 48100 14100 35900 10520 12.0 14.0 3435 1500 708

Conditions: Indoor 80.6°F db / 66.2°F wb / Entering Water Temperature; 86°F

Table 2: Standard ISO Water Loop Cooling at Medium Indoor Fan Speed

Total Cooling Capacity Sensible Capacity Waterow Efciency Power Nominal Airow Unit Size Btuh Watts Btuh Watts GPM EER Watts CFM L/S

024 17000 4980 13400 3930 6.5 14.7 1160 750 354 040 27700 8120 20300 5950 10.0 14.7 1890 1000 472 048 34600 10140 26000 7620 12.0 15.0 2310 1150 542

Conditions: Indoor 80.6°F db / 66.2°F wb / Entering Water Temperature; 86°F

Table 3: Standard ISO Water Loop Cooling at Low Indoor Fan Speed

Total Cooling Capacity Sensible Capacity Waterow Efciency Power Nominal Airow Unit Size Btuh Watts Btuh Watts GPM EER Watts CFM L/S

024 16300 4780 12200 3580 6.5 14.3 1140 650 307 040 26600 7800 18300 5360 10.0 14.4 1845 800 378 048 33700 9880 23700 6950 12.0 14.9 2255 950 448

Conditions: Indoor 80.6°F db / 66.2°F wb / Entering Water Temperature; 86°F

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 45

Unit Selection

Water Loop – Heating (Models ARQ, ERQ)

Table 4: Standard ISO Water Loop Heating at High Indoor Fan Speed

Total Heating Capacity Waterow Efciency Power Nominal Airow Unit Size Btuh Watts GPM COP Watts CFM L/S

024 28500 8350 6.5 4.5 1855 1000 472 040 45900 13450 10.0 4.2 3240 1250 590 048 56000 16410 12.0 4.4 3750 1500 708

Conditions: Indoor 68°F db / 59°F wb / Entering Water Temperature; 68°F

Table 5: Standard ISO Water Loop Heating at Medium Indoor Fan Speed

Total Heating Capacity Waterow Efciency Power Nominal Airow Unit Size Btuh Watts GPM COP Watts CFM L/S

024 19300 5660 6.5 4.8 1180 750 354 040 33300 9760 10.0 4.4 2210 1000 472 048 40300 11810 12.0 4.7 2520 1150 542

Conditions: Indoor 68°F db / 59°F wb / Entering Water Temperature; 68°F

Table 6: Standard ISO Water Loop Heating at Low Indoor Fan Speed

Total Heating Capacity Waterow Efciency Power Nominal Airow Unit Size Btuh Watts GPM COP Watts CFM L/S

024 18600 5450 6.5 4.5 1215 650 307 040 32300 9470 10.0 4.0 2355 800 378 048 39200 11490 12.0 4.4 2620 950 448

Conditions: Indoor 68°F db / 59°F wb / Entering Water Temperature; 68°F

Ground Water – Cooling (Model GRQ)

Table 7: Standard ISO Ground Water Cooling at High Indoor Fan Speed

Total Cooling Capacity Sensible Capacity Waterow Efciency Power Nominal Airow Unit Size Btuh Watts Btuh Watts GPM EER Watts CFM L/S

024 25500 7470 19100 5600 6.5 18.6 1370 1000 472 040 42400 12430 29100 8530 10.0 18.6 2275 1250 590 048 53100 15560 37700 11050 12.0 19.6 2710 1500 708

Conditions: Indoor 80.6°F db / 66.2°F wb / Entering Water Temperature; 59°F

Table 8: Standard ISO Ground Water Cooling at Medium Indoor Fan Speed

Total Cooling Capacity Sensible Capacity Waterow Efciency Power Nominal Airow Unit Size Btuh Watts Btuh Watts GPM EER Watts CFM L/S

024 18900 5540 14300 4190 6.5 22.8 830 750 354 040 31000 9090 22100 6480 10.0 22.5 1380 1000 472 048 38800 11370 27500 8060 12.0 23.4 1660 1150 542

Conditions: Indoor 80.6°F db / 66.2°F wb / Entering Water Temperature; 59°F

Table 9: Standard ISO Ground Water Cooling at Low Indoor Fan Speed

Total Cooling Capacity Sensible Capacity Waterow Efciency Power Nominal Airow Unit Size Btuh Watts Btuh Watts GPM EER Watts CFM L/S

024 18100 5310 13000 3810 6.5 22.5 805 650 307 040 29500 8650 19700 5770 10.0 22.1 1335 800 378 048 37900 11110 25400 7440 12.0 23.4 1620 950 448

Conditions: Indoor 80.6°F db / 66.2°F wb / Entering Water Temperature; 59°F

46 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Unit Selection

Ground Water – Heating (Model GRQ)

Table 10: Standard ISO Ground Water Heating at High Indoor Fan Speed

Total Heating Capacity Waterow Efciency Power Nominal Airow Unit Size Btuh Watts GPM COP Watts CFM L/S

024 23000 6740 6.5 3.9 1710 1000 472 040 40500 11870 10.0 3.9 3080 1250 590 048 45000 13190 12.0 3.9 3365 1500 708

Conditions: Indoor 68°F db / 59°F wb / Entering Water Temperature; 50°F

Table 11: Partial Load ISO Ground Water Heating at Medium Indoor Fan Speed

Total Heating Capacity Waterow Efciency Power Nominal Airow Unit Size Btuh Watts GPM COP Watts CFM L/S

024 15500 4540 6.5 3.9 1155 750 354 040 28200 8270 10.0 3.9 2125 1000 472 048 31800 9320 12.0 3.9 2390 1150 542

Conditions: Indoor 68°F db / 59°F wb / Entering Water Temperature; 50°F

Table 12: Partial Load ISO Ground Water Heating at Low Indoor Fan Speed

Total Heating Capacity Waterow Efciency Power Nominal Airow Unit Size Btuh Watts GPM COP Watts CFM L/S

024 14800 4340 6.5 3.7 1180 650 307 040 26900 7880 10.0 3.5 2260 800 378 048 31500 9230 12.0 3.8 2455 950 448

Conditions: Indoor 68°F db / 59°F wb / Entering Water Temperature; 50°F

Ground Loop – Cooling (Model GRQ)

Table 13: Standard ISO Ground Loop Cooling at High Indoor Fan Speed

Total Cooling Capacity Sensible Capacity Coolant ow Efciency Power Nominal Airow Unit Size Btuh Watts Btuh Watts GPM EER Watts CFM L/S

024 23800 6980 18100 5310 6.5 14.6 1635 1000 472 040 40300 11810 28400 8320 10.0 15.0 2695 1250 590 048 49800 14600 36500 10700 12.0 15.6 3195 1500 708

Conditions: Indoor 80.6°F db / 66.2°F wb / Coolant Temperature; 77°F

Table 14: Partial Load ISO Ground Loop Cooling at Medium Indoor Fan Speed

Total Cooling Capacity Sensible Capacity Coolant ow Efciency Power Nominal Airow Unit Size Btuh Watts Btuh Watts GPM EER Watts CFM L/S

024 18300 5360 14000 4100 6.5 19.5 940 750 354 040 29900 8760 21500 6300 10.0 19.3 1550 1000 472 048 37400 10960 27000 7910 12.0 19.9 1875 1150 542

Conditions: Indoor 80.6°F db / 66.2°F wb / Coolant Temperature; 68°F

Table 15: Partial Load ISO Ground Loop Cooling at Low Indoor Fan Speed

Total Cooling Capacity Sensible Capacity Coolant ow Efciency Power Nominal Airow Unit Size Btuh Watts Btuh Watts GPM EER Watts CFM L/S

024 17500 5130 12700 3720 6.5 19.1 915 650 307 040 28500 8350 19200 5630 10.0 18.9 1505 800 378 048 36500 10700 24800 7270 12.0 19.9 1830 950 448

Conditions: Indoor 80.6°F db / 66.2°F wb / Coolant Temperature; 68°F

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 47

Unit Selection

Ground Loop – Heating (Model GRQ)

Table 16: Standard ISO Ground Loop Heating at High Indoor Fan Speed

Total Heating Capacity Coolant Flow Efciency Power Nominal Airow Unit Size Btuh Watts GPM COP Watts CFM L/S

024 17500 5130 6.5 3.3 1565 1000 472 040 35100 10290 10.0 3.5 2920 1250 590 048 34000 9970 12.0 3.3 2980 1500 708

Conditions: Indoor 68°F db / 59°F wb / Coolant Temperature; 32°F

Table 17: Partial Load ISO Ground Loop Heating at Medium Indoor Fan Speed

Total Heating Capacity Coolant Flow Efciency Power Nominal Airow Unit Size Btuh Watts GPM COP Watts CFM L/S

024 13600 3990 6.5 3.5 1140 750 354 040 25600 7500 10.0 3.6 2085 1000 472 048 27600 8090 12.0 3.5 2325 1150 542

Conditions: Indoor 68°F db / 59°F wb / Coolant Temperature; 41°F

Table 18: Partial Load ISO Ground Loop Heating at Low Indoor Fan Speed

Total Heating Capacity Coolant Flow Efciency Power Nominal Airow Unit Size Btuh Watts GPM COP Watts CFM L/S

024 12900 3780 6.5 3.2 1165 650 307 040 24200 7090 10.0 3.2 2210 800 378 048 27600 8090 12.0 3.4 2370 950 448

Conditions: Indoor 68°F db / 59°F wb / Coolant Temperature; 41°F

48 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Unit Selection

Selection Procedure

Step 1: Determine Design Conditions

Determine design indoor and outdoor air temperatures 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 natural 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 denite number of room air volumes per

hour. Table 19 gives the recommended number of room air changes per hour.

Table 19: Recommended Room Air Changes Per Hour

Type of Space

Classrooms, Ofces 6 to 9

Laboratories, Shops 6 to 8 Cafeterias & Kitchens 4-1/2 to 7

Recommended number of

room air changes per Hour

Equation 6: CFM For Given Rate Of Circulation

Room Volume (cu ft) × Room Changes per Hour 60

= CFM

In mechanical cooling applications, the total air quantity

may be determined or veried by use of the sensible

cooling load equation:

Equation 7: CFM Based On Sensible Cooling Load

1.086 x TD

Q sensible (space)

CFM =

Q sensible is the maximum sensible room load and T.D. is the temperature difference between the room design

dry bulb temperature and the nal 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 gure may be varied one 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 school applications. 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. Lower 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, 1250 and 1500 CFM. Unit sizes 024, 040, and 048.

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

Heating Capacity

Unit heating capacity should be selected to equal or slightly exceed the computed room heat loss. The heating required to warm the outdoor ventilating air up to room temperature must also be calculated.

any given rate of circulation:

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 49

Unit Selection

Cooling Capacity

Unit cooling capacity should be selected to equal or slightly exceed the sum of computed room sensible and latent heat gains (Room Total Capacity). When operating 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.

Antifreeze Correction Factors

Ethylene Glycol

Cooling Capacity 0.9950 0.9920 0.9870 0.9830 0.9790 Heating Capacity 0.9910 0.9820 0.9770 0.9690 0.9610 Pressure Drop 1.0700 1.1300 1.1800 1.2600 1.2800

Propylene Glycol

Cooling Capacity 0.9900 0.9800 0.9700 0.9600 0.9500 Heating Capacity 0.9870 0.9750 0.9620 0.9420 0.9300 Pressure Drop 1.0700 1.1500 1.2500 1.3700 1.4200

10% 20% 30% 40% 50%

Methanol

10% 20% 30% 40% 50%

Cooling Capacity 0.9980 0.9720 – – – Heating Capacity 0.9950 0.9700 – – – Pressure Drop 1.0230 1.0570 – – –

Ethanol

Cooling Capacity 0.9910 0.9510 – – – Heating Capacity 0.9950 0.9600 – – – Pressure Drop 1.0350 1.0680 – – –

10% 20% 30% 40% 50%

50 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Unit Selection

Engineering Data

Table 24: Electrical Data Model ARQ, ERQ, GRQ – Size 024

Voltage Range Voltage

Min. Max.

Room

Fan Heater Heater Maximum

FLA

208/60/1 197 228 2.7 11.4 52.0

High (6-elem.) 16.0 76.9 113.1 125

230/60/1 207 253 2.7 11.4 52.0 High (6-elem.) 15.3 66.7 100.3 110

208/60/3 197 228 2.7 7.9 59.0 High (6-elem.) 16.0 44.4 68.1 80

230/60/3 207 253 2.7 7.9 59.0 High (6-elem.) 15.3 38.5 60.7 70

460/60/3 414 506 2.7 3.9 29.7 High (6-elem.) 15.3 19.2 31.6 35

Notes:

Electric Heat Options are with Compressor

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

Compressor Heating Options Power Supply

RLA LRA Heat Type

Refrigerant Heating Only

Electric Heat

Refrigerant Heating Only

Electric Heat

Refrigerant Heating Only

Electric Heat

Refrigerant Heating Only

Electric Heat

Refrigerant Heating Only

Electric Heat

kW Amps

– – 1 7.0 25

Low (3-elem.) 8.0 38.5 65.0 70

– – 17.0 25

Low (3-elem.) 7.7 33.3 58.6 60

– – 12.6 20

Low (3-elem.) 8.0 22.2 40.3 45

– – 12.6 20

Low (3-elem.) 7.7 19.2 36.6 40

– – 7.6 15

Low (3-elem.) 7.7 9.6 19.6 20

MCA

Fuse

Table 25: Electrical Data Model ARQ, ERQ, GRQ – Size 040

Voltage Range Voltage

Min. Max.

Room

Fan Heater Heater Maximum

FLA

208/60/1 197 228 2.7 18.6 96.0

High (6-elem.) 20.0 96.2 146.1 150

230/60/1 207 253 2.7 18.6 96.0 High (6-elem.) 19.2 83.3 130.1 150

208/60/3 197 228 2.7 15.0 88.0 High (6-elem.) 20.0 55.5 90.8 100

230/60/3 207 253 2.7 15.0 88.0 High (6-elem.) 19.2 48.1 81.6 90

460/60/3 414 506 2.7 6.8 44.0 High (6-elem.) 19.2 24.1 41.3 45

Notes:

Electric Heat Options are with Compressor

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

Compressor Heating Options Power Supply

RLA LRA Heat Type

Refrigerant Heating Only

Electric Heat

Refrigerant Heating Only

Electric Heat

Refrigerant Heating Only

Electric Heat

Refrigerant Heating Only

Electric Heat

Refrigerant Heating Only

Electric Heat

kW Amps

– – 26.0 40

Low (3-elem.) 10.0 48.1 86.0 90

– – 26.0 40

Low (3-elem.) 9.6 41.7 78.0 80

– – 21.5 35

Low (3-elem.) 10.0 27.8 56.1 60

– – 21.5 35

Low (3-elem.) 9.6 24.1 51.5 60

– – 11.2 15

Low (3-elem.) 9.6 12.0 26.2 30

MCA

Fuse

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 51

Unit Selection

Engineering Data

Table 26: Electrical Data Model ARQ, ERQ, GRQ – Size 048

Voltage Range Voltage

Min. Max.

Room

Fan Heater Heater Maximum

FLA

208/60/1 197 228 2.7 23.6 96.0

High (6-elem.) 24.0 115.4 176.4 200

230/60/1 207 253 2.7 23.6 96.0 High (6-elem.) 23.0 100.0 157.2 175

208/60/3 197 228 2.7 15.0 88.0 High (6-elem.) 24.0 66.6 104.7 110

230/60/3 207 253 2.7 15.0 88.0 High (6-elem.) 23.0 57.7 93.6 100

460/60/3 414 506 2.7 7.1 41.0 High (6-elem.) 23.0 28.9 47.7 50

Notes:

Electric Heat Options are with Compressor

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

Compressor Heating Options Power Supply

RLA LRA Heat Type

Refrigerant Heating Only

Electric Heat

Refrigerant Heating Only

Electric Heat

Refrigerant Heating Only

Electric Heat

Refrigerant Heating Only

Electric Heat

Refrigerant Heating Only

Electric Heat

kW Amps

– – 32.2 50

Low (3-elem.) 12.0 57.7 104.3 110

– – 32.2 50

Low (3-elem.) 11.5 50.0 94.7 100

– – 21.5 35

Low (3-elem.) 12.0 33.3 63.1 70

– – 21.5 35

Low (3-elem.) 11.5 28.9 57.5 70

– – 11.6 15

Low (3-elem.) 11.5 14.4 29.6 30

MCA

Fuse

Table 27: Model AR, ER, GR Basic Unit Data

Models ARQ, ERQ, GRQ 024 040 048

Nominal Airow – CFM (L/S) 1000 (472) 1250 (590) 1500 (708)

Width - In. (MM) 8.25 (210) 8.25 (210) 8.25 (210)

Room Fan Motor Horse Power 1/4

Nom. Size – In. (MM) 10 × 48½ × 1 (254 × 1232 × 25) 10 x 60½ × 1 (254 × 1537 × 25) 10 × 36½ × 1 (254 × 927 × 25)

No. of Fans 3 4 4

Room

Fan Data

Dia. – In. (MM) 8.12 (206) 8.12 (206)

1/4

8.12 (206)

1/4

Filter Data Area – FT2 (M2) 3.37 (0.31) 4.20 (0.39) 5.08 (0.47) Quantity 1 1 2

Approx. Ship Weight – Lbs. (KG) 690 (310) 720 (325) 760 (340) Refrigerant Charge – Oz. 84 130 100

52 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Details & Dimensions

opening for outdoor air,

must be within 55" × 21"

1 Control Compartment

2 Compressor Compartment

3 Unit Mounting Holes

4 Unit Power On/Off Switch

5 Unit Power Wiring Entry

Note: If wall is chased, wall

(Open Pipe Tunnel) or

55" × 28" (Closed Pipe Tunnel).

Figure 56: Unit Size 024 Dimensions

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 53

Details & Dimensions

opening for outdoor air, must

be within 67" × 21" (Open

2 Compressor Compartment

3 Unit Mounting Holes

4 Unit Power On/Off Switch

5 Unit Power Wiring Entry

Note: If wall is chased, wall

Pipe Tunnel) or

67" × 28" (Closed Pipe

Tunnel).

Figure 57: Unit Size 040 Dimensions 1 Control Compartment

54 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Details & Dimensions

opening for outdoor air,

must be within

1 Control Compartment

2 Compressor Compartment

3 Unit Mounting Holes

4 Unit Power On/Off Switch

5 Unit Power Wiring Entry

Note: If wall is chased, wall

79" × 21" (Open Pipe

Tunnel) or 79" × 28"

(Closed Pipe Tunnel).

Figure 58: Unit Size 048 Dimensions

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 55

27 7/8"

(708mm)

/8"

(708mm)

(178mm)

/2"

(64mm)

(25mm)

/8"

(708mm)

18"

(457mm)

(102mm)

(25mm)

/8"

(708mm)

22"

(559mm)

(102mm)

(25mm)

16 5/8"

(422mm)

(25mm)

27 7/8"

(708mm)

28"

(711mm)

(25mm)

/8"

(708mm)

22"

(559mm)

4"(102mm)

(25mm)

/8"

(708mm)

/8"

(708mm)

(178mm)

/2"(64mm)

(25mm)

/8"

(708mm)

22"

(559mm)

(102mm)

(25mm)

/8"

(708mm)

18"

(457mm)

(102mm)

(25mm)

/8"

(708mm)

/8"

(708mm)

(178mm)

/2"(64mm)

(25mm)

/8"

(708mm)

22"

(559mm)

4"(102mm)

(25mm)

/8"

(708mm)

18"

(457mm)

(102mm)

(25mm)

(498mm)

(25mm)

(556mm)

(25mm)

Details & Dimensions

27 7/8"

(708mm)

28"

(711mm)

(25mm)

/8"

(708mm)

22"

(559mm)

4"(102mm)

(25mm)

/8"

(708mm)

/8"

(708mm)

(178mm)

/2"(64mm)

(25mm)

/8"

(708mm)

22"

(559mm)

4"(102mm)

(25mm)

/8"

(708mm)

18"

(457mm)

(102mm)

(25mm)

(556mm)

(25mm)

27 7/8"

(708mm)

/8"

(708mm)

(178mm)

/2"

(64mm)

(25mm)

/8"

(708mm)

18"

(457mm)

(102mm)

(25mm)

/8"

(708mm)

22"

(559mm)

(102mm)

(25mm)

16 5/8"

(422mm)

(25mm)

27 7/8"

(708mm)

28"

(711mm)

(25mm)

/8"

(708mm)

22"

(559mm)

4"(102mm)

(25mm)

/8"

(708mm)

/8"

(708mm)

(178mm)

/2"(64mm)

(25mm)

/8"

(708mm)

22"

(559mm)

(102mm)

(25mm)

/8"

(708mm)

18"

(457mm)

(102mm)

(25mm)

/8"

(708mm)

/8"

(708mm)

(178mm)

/2"(64mm)

(25mm)

/8"

(708mm)

22"

(559mm)

4"(102mm)

(25mm)

/8"

(708mm)

18"

(457mm)

(102mm)

(25mm)

(498mm)

(25mm)

(556mm)

(25mm)

16 5/8"

(422mm)

(152mm)

28"

(711mm)

19 5/8"

(498mm)

/8"

(556mm)

(152mm)

27"

(686mm)

(76mm)

27"

(686mm)

(76mm)

27"

(686mm)

(76mm)

27"

(686mm)

(76mm)

27 7/8"

(708mm)

28"

(711mm)

(25mm)

/8"

(708mm)

22"

(559mm)

4"(102mm)

(25mm)

/8"

(708mm)

/8"

(708mm)

(178mm)

/2"(64mm)

(25mm)

/8"

(708mm)

22"

(559mm)

4"(102mm)

(25mm)

/8"

(708mm)

18"

(457mm)

(102mm)

(25mm)

(556mm)

(25mm)

28"

(711mm)

/8"

(556mm)

(152mm)

27"

(686mm)

(76mm)

27"

(686mm)

(76mm)

End Panel Dimensions

Figure 59: 1" (25mm) and 6" (152mm) End Panel Dimensions – Self-Contained Floor Unit Ventilators

All Dimensions

in Inches

Top View

16⅝" (422mm) Deep

End Panels

21⅞" (556mm) Deep

End Panels

End View

With No

Cut-out

Dashed lines indicate kickplate

End View

with 2½"x 7"

(64mm x 178mm)

with 4" x 18"

Cut-out

End View

(102mm x 457mm)

Cut-out

End View

with 4" x 22"

(102mm x 559mm)

Cut-out

6" (152mm) End Panel Dimensions – Self-Contained Floor Unit Ventilator

Top View

End View

With No

Cut-out

56 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Details & Dimensions

Wall Intake Louvers & Grilles

Louvers are available in both horizontal and vertical

blade congurations:

• Horizontal blade construction turns the incoming air to keep moisture from entering. Bottom weep holes drain moisture to the outside.

• Vertical-blade construction provides positive water impingement and entrapment. The bottom lip drains moisture to the outside.

Louvers can be supplied with or without anges:

• Flanged louvers are typically used for a panel wall

nish.

• Unanged louvers are typically used for recessing into a masonry wall.

Figure 60: Louver with Flange (Horizontal Blades Shown

Grille (Optional)

A half-inch-square mesh bird screen located on the leaving air side of the louver prevents birds and other small animals from entering. The screen’s strong aluminum mesh is designed to minimize air pressure drops, unlike expanded metal mesh.

Table 28 Louver Specications

Unit Flow ± 1/16" (± 2mm) Opening

Nominal Air Louver Dimensions Recommended Wall

Size

CFM L/s L = Length Height Length Height

024 1000 472

040 1250 590

048 1500 708

Bird Screen on Inside

48" 10-3/8" 48-1/4" 10-1/2"

(1219mm) (264mm) (1225mm) (267mm)

60" 10-3/8" 60-1/8" 10-1/2"

(1524mm) (264mm) (1527mm) (267mm)

72" 10-3/8" 72-1/4" 10-1/2"

(1829mm) (264mm) (1835mm) (267mm)

1-1/2" 38mm

Louver Weep Holes in this Area

Figure 61: Louver without Flange (Vertical Blades Shown)

Grille (Optional)

13-3/8" 340mm

10-3/8"

264mm

10-3/8"

264mm

1-1/2" 38mm

Bird Screen on Inside

Louver Weep Holes in this Area

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 57

2-1/4" 57mm

Details & Dimensions

V entimatic 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.

3 Optional interior grille mounting hardware is not

included.

4 Louver leaves seal against plate to prevent air

inltration.

Figure 62: VentiMatic Shutter Assembly with Optional Grille

Two Shutter Assemblies Mounted on One Louver

(See table)

Aluminum Exterior Grille (optional)

Aluminum Louver

Bafe Plate

(See table)

Louver

(See table)

Center Cover

Steel Interior Grille (optional)

Aluminum Exterior Grille (optional)

Steel Interior Grille (optional)

Aluminum Louver

Table 29: Recommended Wall Openings and Max Air Capacities for VentiMatic Shutter Assembly

Exterior Grille Louver Interior Grille Recommended Wall Opening

Width A Width B Width C for Louver

on Standard Louver Air Capacity

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

Length Width

inches mm inches mm

VentiMatic Shutters to Mount Shutter(s) Max.

Maximum Number of VentiMatic

24" (610mm) 36" (914mm)

Shutter Shutter

inches mm

58 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

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 63: Sink and Bubbler

Top View

Faucet

Bubbler

30-1/8"

765mm

3 Sink and bubbler 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

eld installation by the installing contractor.

5 Sink and bubbler top is designed to project 1/16"

higher and 3/16" deeper than the adjoining cabinets, unit ventilator or end panels.

Note: Sink & Bubbler and Storage Cabinets, are

provided by others. Contact your McQuay sales representative for details.

Piping Space

48" (1219mm)

Front Skirt with Air Inlet for

Radiation Style Cabinet

Front View

Figure 64: Standard Storage Cabinet

Front Skirt with Air Inlet for Radiation Style Cabinet or

VentiMatic Shutter

Front View

Solid Skirt for Standard

Style Cabinet

Solid Skirt for Standard

Style Cabinet

30"

762mm

Side View

Total Depth Piping Space

“A” “B”

16-5/8" – 21-7/8" 5-13/16"

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 59

Details & Dimensions

Utility Compartment & Filler Sections

Filler sections are furnished in 18" and 24" lengths. They are provided with enough hardware to assemble

one right hand and one left hand ller having a

combined length of 18”/24" or less. The minimum length

of one ller after cutting is 3". The ller section may be

used between a cabinet and the wall, between a unit and the wall, between a unit and cabinets, or between cabinets.

Figure 65: Accessories

12"

305mm

Top Panel

(Steel)

A A A

Note: Utility Compartments and Filler Sections are

provided by others. Contact your McQuay sales representative for details.

18", 24"

Laminate T op

Utility Compartment

Figure 66: Utility Compartment Details

30"

762mm

(76mm)

12"

(305mm)

Front View

Total Depth Piping Space

“A” “B”

16-5/8" – 21-7/8" 5-13/16"

3" (76mm)

Side View

28"

660mm

14" 356mm

(25mm)

(305mm)

Corner Filler Sections

12"

(305mm)

60 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Wiring Diagrams

Refer to unit wiring diagram located on inside of right front panel, for

CAUTION

USE COPPER CONDUCTORS ONLY.

UNIT TERMINALS ARE NOT DESIGNED TO

DANGER

ACCEPT OTHER TYPES OF CONDUCTORS.

DISCONNECT ALL ELECTRICAL

POWER BEFORE SERVICING

UNIT TO PREVENT INJURY OR

actual wiring. Improper wiring can cause equipment and property

damage.

FAILURE TO DO SO MAY DAMAGE THE

EQUIPMENT.

DEATH DUE TO ELECTRICAL

SHOCK.

MicroTech II Wiring Diagram – Typical

Figure 67 - Water Source Heat Pump DX Cooling w/Electric Heat, Valve Control 460-Volt/3 Phase

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 61

Wiring Diagrams

Typical Wall Sensors Diagram

Figure 68: Wall-Mounted Temperature Sensor Wiring for Wall Sensor

Figure 69: 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

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

908A 907A 906A 905A 904A

896

Wire

Caps

Wire

Caps

Wire

Caps

Shield

External Input

Option 4 Device

(by Others)

WSHP

Boilerless System

(low temp switch)

External Input

Option 3 Device

(by Others)

Ventilation Lockout

(default) or

Exhaust Interlock

Factory Wiring

Field Wiring (by Others)

External Device (by Others)

External Input

Option 2 Device

(by Others)

Remote Shutdown

External Input

Option 1 Device

(by Others)

Unoccupied

Additional Units

62 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Wiring Diagrams

Figure 70: External Output Wiring – Single Unit

Unit Ventilator

UVC

xBO-2

Comm

xBO-1

BO-6

Comm

24vac Supply

24vac Comm

Connector

Wire

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

Shield

Factory Wiring

Field Wiring (by Others)

External Device (by Others)

Figure 71: External Output Wiring – Multiple Units Shown

Unit Ventilator #1

UVC

XBO-2 Comm

XBO-1

BO-6 BO-6

Comm

24vac Supply 24vac Comm

Connector

Wire

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

Shield

Unit Ventilator #2

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

Unit Ventilator #...X (last unit)

UVC

XBO-2 Comm

XBO-1

BO-6 BO-6

Comm

24vac Supply 24vac Comm

Connector

Wire

Caps 601A

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

External Output Option 1 Device

(by Others)

Lights On/Off

Signal

Motorized Water

Valve Open/Close

Additional Units

External Output

Option 2 Device

(by Others)

Fault Indication

Pump Restart

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)

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 63

Guide Specications

AAF-HermanNelson Self-Contained Water Source Heat Pump Unit Ventilator

Model ARQ, ERQ & GRQ Guide Specications

General

Furnish and install where shown on plans, with unit capacities and characteristics as listed in schedule for self-contained water source heat pump units.

Unit Construction

All internal sheet metal parts must be made of galvanized steel to inhibit corrosion. The entire frame must be welded construction to provide strength and rigidity. Hidden reinforced top panel support shall be integral with the frame and support the fan assembly. Frames assembled with sheet metal fasteners shall not be acceptable. Unit shall be of a draw-thru design. Blow-thru design is not acceptable. Unit shall have a built-in metal wire raceway from one end compartment to the other.

Cabinets

Exterior cabinet panels shall be constructed of heavy gauge steel. All sheet metal panels must be cleaned and phosphatized, then painted electrostatically with an oven baked environmentally friendly thermosetting

urethane powder nish. Opening or removing the unit

left- or right-hand front panels shall not affect unit operation in order to facilitate testing and servicing. Internal sheet metal parts shall be constructed of galvanized steel to inhibit corrosion. Unit discharge grille shall be constructed of continuous round edged

steel bars to provide 10-degrees vertical deection. Adjustable side deection vanes shall be provided

beneath the discharge grille to provide optimum lateral

air distribution. Cabinet depth shall not exceed 16-5⁄8" (422mm) [21-7⁄8" (566mm) if adapter back is used]. [A 1⁄4" (6mm) mesh screen shall be provided beneath the

discharge grille to protect against objects being dropped

through the discharge grille.] Unit shall have glass ber

blanket insulation. This shall act as an outdoor air seal

on 16-5⁄8 (422mm) deep units. Units that are 21-7⁄8" (566mm) deep shall also have glass ber blanket

insulation on those adapter back parts which come In

contact with outdoor air. Units that are 21-7⁄8" (566mm)

deep shall have a vinyl foam air seal which shall go around the perimeter of the wall opening for the wall intake louver.

Fan and Motor

The motor and fan assembly shall be low speed

designed to assure maximum quietness and efciency.

Fans shall be double inlet, forward curved centrifugal type. Fan wheels shall be constructed of dark, high density, injection molded polypropylene having high impact strength, chemical resistance and thermal stability. Assembly shall be statically and dynamically balanced. Fan housings shall be of steel construction.

Fan shaft shall be 1-1⁄4" (32mm) diameter, hollow steel with 1-1⁄4" (32mm) bearing. Fan and motor

assembly shall be direct drive type. Motor speed shall be controlled by factory furnished and mounted multitap transformer through High-Off-Low switch. Fan/ coil arrangement shall be draw-thru design for uniform coil face velocity and discharge air temperature In addition to providing the kinetic energy for optimum air distribution. Motors shall be permanent split capacitor

(PSC), plug-in type designed specically for unit

ventilator operation. Motors shall be located out of the airstream and have an internal thermal overload device (auto-reset). Fan motors and controls shall have each hot line protected by factory Installed cartridge type fuse(s). All components of the fan/motor assembly shall be removable from the front of the unit. The motor and fan shaft shall have sleeve type bearings with precision tolerances and shall not require oiling more than once annually.

Outdoor/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 using metalforming techniques to resist twisting and shall be counterbalanced against back pressure. Outdoor air damper shall be two-piece double-wall construction

with 1/2" thick, 1.5 lbs. density berglass insulation

encapsulated between welded 20 ga. galvanized steel blades for rigidity and to inhibit corrosion, and have additional insulation on the exterior surfaces of the damper blade and on the ends of the outdoor air

chamber. Dampers shall be tted with mohair seals

along all the sealing edges. Dampers shall use turnedmetal principle on long closing ends with no metal-tometal contact. No plastic or rubber gaskets shall be acceptable. Damper bearings shall be made of nylon or other material which does not require lubrication.

64 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Guide Specications

Drain Pan

All units shall have a drain pan constructed of corrosion resistant composite. A drain outlet shall be provided on both ends of the pan. The drain hand of connection

shall be easily eld reversed to the opposite end. The

drain pan shall be able to be sloped in either direction for proper condensate removal. Drain shall be provided

with an optional secondary, overow drain connection

on both ends of the pan.

Agency Listing

Unit ventilators shall be listed by Underwriters Laboratories Inc. (U.L.) for the United States and Canada. Unit ventilation rated per AHRI standard

840. Motors shall conform to the latest applicable requirements of NEMA, IEEE, ANSI, and NEC

standards. Unit to be certied and labeled compliant

with the seismic design provisions of the International Building Code (IBC) Chapter 16 and independent test agency requirements of Chapter 17.

Refrigeration System

The refrigeration section shall be constructed of galvanized steel and shall include a factory sealed compressor, a water-to-refrigerant coil, and air-to refrigerant coil and reversing valve. The reversing valve shall have a replaceable external solenoid coil which is energized only when space heating is required. The equipment manufacturer is to be fully responsible for the integrity of the refrigerant piping and the entire refrigeration circuit, including compressor, water-torefrigerant coil and air-to-refrigerant coil, 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 phase units shall have permanent split capacitor (PSC) compressor motor with start assist consisting of a compressor start capacitor and compressor start relay.

Units with three-phase power: Shall utilize threephase compressors for balanced electrical compressor loads.

The condenser coil shall be constructed of copper tubes mechanically expanded to embossed aluminum

plate ns. 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 ns

mechanically bonded thereto and shall be positioned above a plastic drain pan. Refrigerant shall be metered by a thermostatic expansion valve in lieu of capillary tubing to achieve evaporator performance and to protect

the compressor from oodback of liquid refrigerant.

The refrigerant section shall be adequately insulated to prevent “sweating.” The unit shall be furnished and wired with compressor thermal/current overload and high pressure cutout. Gauge ports shall be provided to allow reading of 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. The water-to-refrigerant coil shall be stainless steel plate- to plate heat exchanger. Either type shall be constructed to be suitable for 300 lbs. (2069 kPa) water working pressure and 450 lbs. (3104 kPa) refrigerant pressure. Refrigerant (R-410A) shall be metered by a thermostatic expansion valve In lieu of capillary tubing to achieve balanced evaporator performance

and to protect the compressor from oodback of liquid

refrigerant. The refrigerant section shall be adequately insulated to prevent “sweating.” The unit shall be furnished and wired with the following safety devices: compressor thermal/current overloads and high pressure cutout switch. Gauge ports shall be provided to allow reading of refrigerant pressures at the suction and discharge of the compressor.

Filter

Filter shall be one-piece type. Throwaway lter shall be

factory furnished initially installed in the unit. [Option: Furnish _____________ extra set(s) of throw-

away lters.]

[Option: Furnish one set of wire mesh permanent lters as nal lter.]

[Option: Furnish one set of renewable (metal frame with

glass ber media) lters as nal lter.]

[Option: Furnish _____________ roll(s) of renewable

lter media.]

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 65

Guide Specications

(Optional] Boilerless Systems

Units shall utilize reverse cycle operation for heating until the water loop temperature drops below 60°F

(16°C), [50°F (10°C) ERQ, 20°F (-6°C) GRQ], at

which time the unit switches over to electric resistance heating. Heating elements shall be of the open wire type. Units have up to three stages of electric heat. A capillary tube 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 deenergize the electric resistance heating coil when the center front access panel is opened.

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 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 reector and to increase the strength of the

material. Damping material shall be textured foam type. The exterior of the compressor compartment shall be coated with a high density damping material to eliminate 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.

VentiMatic Shutter (Room Exhaust)

Where indicated, the unit ventilator manufacturer shall provide an “in-room” air relief VentiMatic shutter mounted on a separate wall intake louver to prevent excessive static pressure build-up In the room. The VentiMatic shutter shall be constructed of galvanized steel with shutter dampers of woven glass fabric impregnated with silicone rubber.

Temperature Controls

Each unit ventilator shall be furnished with a factory installed and wired, microprocessor based DDC Unit Ventilator Controller (UVC), by the manufacturer of the unit ventilator, which is pre-programmed, factory pretested prior to shipment and capable of complete, standalone unit control, master-slave arrangement or incorporation into a building-wide network using an optional plug-in communication module. The UVC shall be preprogrammed with the application code required to operate the unit using ASHRAE Cycle II. The unit control system shall include all required temperature

sensors, input/output boards, main microprocessor modules, Local User Interface (referred to as LUI) Touch Pad with Digital LED Display, wiring, 24 volt power and direct coupled damper actuators. The UVC shall support up to 6 analog inputs, 12 binary inputs, and 9 binary outputs plus additional I/O points of 4 analog inputs and 8 binary outputs.

Network System

1. The unit control system shall perform all unit control functions, unit diagnostics and safeties. The unit shall operate in the standalone or network capable mode of AAF-HermanNelson Model AR, ER, GR

Unit Ventilators 103 Guide Specications operation.

Field furnished and installed controls shall not be allowed. When network capable, network communication modules shall be factory installed, tested and able to communicate via plug-in communication modules that connect directly to the UVC using:

SELECT one:

a. LonMark Space Comfort Control that supports the

LonMark SCC prole number 8500-10 allowing

LonWorks network communication capability to the UVC.

b. BACnet Master Slave/Token Passing (MS/TP) al-

lowing the UVC to inter-operate with systems that use the BACnet (MS/TP) protocol with a conformance level of 3 meeting the requirements of ANSI/ ASHRAE 135- 1955 standard for BACnet systems.

c. Metasys N2 Open allowing Metasys N2 Open net-

work communication capability to the UVC.

2. Controls shall allow monitoring and adjustment from a portable IBM compatible PC using the applicable software. When using this PC and software, the unit shall be capable of reacting to commands for changes in control sequence and set points.

Room Temperature Sensor and Tenant Override Options Unit Mounted

All units shall come equipped with a factory mounted room temperature sensor located in a sampling chamber (front, center panel) where room air is continuously drawn through for fast response to temperature changes in the room. When using a remote wall-mounted temperature sensor the ability shall exist to simply disconnect the unit-mounted temperature sensor using the provided quick disconnect plug. Tenant override switch shall be factory mounted next to the Local User Interface (LUI) Touch Pad to provide a momentary contact closure that causes the unit to enter the “tenant override” operating mode for a set

66 AAF-HermanNelson Model AR, ER & GR Unit Ventilator

Guide Specications

time period (adjustable) of 120 minutes. The room temperature sensor and override switch shall (SELECT one):

A both be unit-mounted. B be an optional wall-mounted temperature sensor,

with integral tenant override capability

Wall-Mounted Sensor with Tenant Override

A thermistor type temperature sensor with integral tenant override and status LED shall be furnished with the unit ventilators.

SELECT one:

A Remote wall-mounted sensor with tenant override B Expanded remote wall-mounted sensor with room

set point adjustment capability of zero plus or minus 3°F (1.5°C)

Night Controls

Night set-back/set-up control shall be provided by

SELECT one:

A A factory mounted and wired digital time clock

(optional for standalone operation) which shall cycle the unit ventilator through occupied and unoccupied modes in accordance with one of twenty (20) user programmed time schedules.

B A remote mounted time clock as described in the

temperature control specication and provided by

the automatic temperature controls contractor. The unit in standalone mode shall have a single set of dry contacts to signal unoccupied or occupied mode.

C The network DDC control system.

[Accessory] Outdoor Air Intake Louver

Intake louvers shall be in the quantity and size shown

on the plans and specications, and as manufactured by

AAF-HermanNelson.

[Accessory] Horizontal Blade Aluminum Louver

Aluminum masonry louver shall be constructed with horizontal chevron-type, heavy-gauge aluminum blades and aluminum frame. The standard aluminum alloy shall be suitable for color anodizing (by others) or for factory painting. Weep holes shall be provided in the louver frame. A 1/2" square mesh screen shall be furnished on the interior side of the louver. Expanded metal is

not acceptable. Louver shall be fabricated of mill nish

AQ5005 aluminum. [Optional: Louver shall be (1)

aluminum with clear anodized nish (2) aluminum with an oven-baked powder paint nish. (3) unpainted.]

[Accessory] Vertical Blade Louver

Vertical blade aluminum louver shall be constructed with double-break, aluminum blades for mounting in panel wall or masonry wall applications. The louver frame shall be heavy-gauge aluminum, 2-1/4" deep in direction

of airow, and have weep holes along face of bottom

edge. The standard aluminum alloy shall be suitable for color anodizing (by others) or for factory painting. A 1/2" square mesh screen shall be provided on the interior side of the louver. Louver shall be fabricated of

mill nish AQ5005 aluminum. [Optional: Louver shall be (1) aluminum with clear anodized nish (2) aluminum with an oven-baked powder paint nish (3) unpainted. A four-sided ange shall be provided around perimeter of intake of same material and nish as louver.]

External Signal Connections

The unit shall have three (3) multi-pin External Signal Connection Plugs factory provided and pre-wired with

short wire whips that are capped for eld wiring of:

A Remote Wall-Mounted Temperature Sensor. B External Input Signals (by others) availability depen-

dent upon unit conguration: unoccupied, remote

shutdown, ventilation lockout, dew point/ humidity, or exhaust interlock signals.

C External Output Options (by others) availability

dependent upon unit conguration: lights on/off,

motorized water valve open/close, fault indication signal, pump restart, exhaust fan on/off or auxiliary heat signal.

AAF-HermanNelson Model AR, ER & GR Unit Ventilator 67

[Accessory] Grille

Decorative aluminum intake grille shall be constructed of heavy-gauge aluminum with square holes to match the louver opening, maximizing the air opening. The grille shall come with holes for mounting to building exteriors. The standard aluminum alloy AQ5005 shall be suitable for color anodizing (by others) or for factory painting.

McQuay Training and Development

Now that you have made an investment in modern, efcient 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 nd your local McQuay Representative, go to www.mcquay.com.

This document contains the most current product information as of this printing. For the most up-to-date product information, please go to www.mcquay.com.

Manufactured in an ISO Certied Facility

CAT 1640 (12-10)

McQuay ARQ024 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual