Honeywell Economizer Controls Technical Reference Manual

Technical Reference Manual

Design and Application Guide for Honeywell Economizer Controls

63-8594-02

Table of Contents
Section 1 - Ventilation ...................................................................................	1
Indoor Air Quality ...............................................................................................................................................................	2
Building-Related Illness .....................................................................................................................................................	3
Symptoms of Inadequate Ventilation .................................................................................................................................	4
Indoor Air Ventilation Standards .........................................................................................................................................	5
CO2 Based Demand Control Ventilation .................................................................................................................	5
Energy Standards ..............................................................................................................................................................	6
Ventilation Requirements .................................................................................................................................................	7
Air Handler Control Loops ..................................................................................................................................................	9
Basic Economizer Control ................................................................................................................................................	10
Mixed Air Formulas ..........................................................................................................................................................	11
Outside Air Percentage Chart ..........................................................................................................................................	12
Example 1: Using the Outside Air Percentage Chart ............................................................................................	13
Example 2: Use of Outside Air Chart on a Warm Day ..........................................................................................	14
Extra Outside Air Percentage Chart ......................................................................................................................	15
Example 3: Minimum Ventilation Adjustment ........................................................................................................	16
Example 4: Ventilation Review Questions .............................................................................................................	18
Economizer Cycle Definition ............................................................................................................................................	20
Single and Two Stage Cooling With Economizer ..................................................................................................	21
Section 2 - Enthalpy Theory And Controllers ...........................................	23
The Psychrometric Chart .................................................................................................................................................	24
Relative Humidity and Saturation .....................................................................................................................................	25
Enthalpy...........................................................................................................................................................................	26
Psychrometric Chart of Enthalpy Economizer Control ..........................................................................................	27
Single Sensor Enthalpy Control .......................................................................................................................................	28
Two Sensor or Differential Enthalpy .................................................................................................................................	29
Enthalpy Control with Carbon Dioxide Sensor .................................................................................................................	30
Section 3 - Types of Analog Economizers ................................................	31
H705 ................................................................................................................................................................................	32
W7459 .............................................................................................................................................................................	33
W6210 and W7210 ..........................................................................................................................................................	34
W6215, W7215 and W7460 .............................................................................................................................................	35
W7212, W7213 and W7214 .............................................................................................................................................	36
W7340 and W7345 ..........................................................................................................................................................	37
Analog Economizer Features ...........................................................................................................................................	38
Transformer Wiring Requirements for Analog Economizers ............................................................................................	39
Section 4 - H705 Economizer Module ........................................................	41
H705 Economizer Module ................................................................................................................................................	42
H705 Components ...........................................................................................................................................................	43
H705 Enthalpy Setpoint ...................................................................................................................................................	44
H705 Wiring Diagram .......................................................................................................................................................	45
Section 5 - M7XXX Black Motor ..................................................................	49
M7215, M7415, M7405 and M8405 Actuators .................................................................................................................	50

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Section 6 - W7459 Economizer Module .....................................................	53
W7459 Enthalpy Module Components .............................................................................................................................	54
W7459A, B, C and D ........................................................................................................................................................	56
W7459 Enthalpy Setpoint Chart .......................................................................................................................................	57
High Limit Switching .........................................................................................................................................................	58
W7459A Wiring Diagram .................................................................................................................................................	59
Section 7 - W6210 And W7210 Economizer Modules ...............................	63
W7210 Economizer System Components .......................................................................................................................	64
W6210 and W7210 Components .....................................................................................................................................	65
High Limit Function ................................................................................................................................................	65
W7210 Actuator Connections .........................................................................................................................................	66
W7210 Wiring Diagrams ..................................................................................................................................................	67
Section 8- W6215, W7215 And W7460 Economizer Modules ...................	69
W7215 System Components ...........................................................................................................................................	70
W6215, W7215 and W7460 Components ........................................................................................................................	71
W7215B and W7460B Components ................................................................................................................................	71
W6215, W7215, W7460 Inputs and Outputs ....................................................................................................................	72
Input and Output Applications ..........................................................................................................................................	72
Minimum and Maximum Settings .....................................................................................................................................	73
Indoor Air Content Sensor Settings .................................................................................................................................	74
Carbon Dioxide Sensor Setup .........................................................................................................................................	75
Outdoor Air Content Sensor .............................................................................................................................................	76
W6215, W7215 and W7460 Actuator Usage ...................................................................................................................	77
W6215, W7215 and W7460 Wiring Diagram ..................................................................................................................	78
Section 9 - W7212, W7213 and W7214 Economizer Modules ..................	81
W7212 Economizer System Components .......................................................................................................................	82
W7212, W7213, and W7214 Components .......................................................................................................................	83
DCV Maximum Position Adjustment ......................................................................................................................	84
Using Multiple CO2 sensors on the AQ-AQ1 terminals for zones .........................................................................	85
Minimum Position Adjustment ...............................................................................................................................	85
Dry bulb changeover .............................................................................................................................................	86
W7212, W7213, and W7214 Wiring Diagram ..................................................................................................................	87
Section 10 - W7340 and W7345 Economizer Module ................................	93
W7340 Economizer System Components .......................................................................................................................	94
W7340 and W7345 Components .....................................................................................................................................	96
W7340 only ...........................................................................................................................................................	97
Demand Control Ventilation (DCV) Sensor Input (W7340 only) ............................................................................	97
Settings and Adjustment .......................................................................................................................................	99
Wiring for W7340 and W7345 ........................................................................................................................................	101
Section 11 - W7220 JADE™ Economizer Module ...................................	103
W7220 Economizer System Components .....................................................................................................................	104
W7220 Components ......................................................................................................................................................	106
Wiring Application Examples .........................................................................................................................................	109
W7220 (JADE™) Economizer Controller Used with Honeywell Prestige© IAQ 2.0 Thermostat ....................................	129
Alarm Mode for Failed Components on the JADE™ economizer system ...........................................................	129
W7220 Personal Computer Tool ....................................................................................................................................	134
Section 12 - Sensors for Economizer Modules .......................................	157
Sensor Features ............................................................................................................................................................	158
Type of Sensors for Economizer ....................................................................................................................................	159
C7150 and C7046 Mixed and Supply Air Sensors .........................................................................................................	162

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Mixed or Supply Air Sensor Control Sequence ..............................................................................................................	163
Carbon Dioxide Sensor ..................................................................................................................................................	163
JADETM Economizer (W7220) Sensors .........................................................................................................................	164
Section 13 - Checkout ...............................................................................	167
Standard Checkout Procedure .......................................................................................................................................	168
Checkout W7212 ...........................................................................................................................................................	168
Check out C7400 with W7459, W7210 and W7212 .......................................................................................................	170
Check out for W7220 JADETM Economizer ...................................................................................................................	172
Section 14 - Simulator for W7212 .............................................................	173
Section 15 - Demo for W7220 ...................................................................	177
Section 16 – Economizer Savings Estimator .........................................	181
Section 17 - Retrofit and Upgrades ..........................................................	183
Replacement of W7459Axxx and M7415Axxx with W7220A1000 (JADETM) and M7215A1008 ................................	188
Replacement of W7212Axxx with W7220A1000 (JADETM) ..........................................................................................	191
Replacement of W7210Axxx with W7220A1000 (JADETM) ..........................................................................................	193
Replacement of W859F with W7220A1000 (JADETM) and M7285A1045 .....................................................................	195
Replacement of W957G with W7220A1000 (JADETM) and M7285A1045 ....................................................................	197
W957G Replaced with W7220 and M7285A1045 Mod Motor .............................................................................	198
Cross Reference ............................................................................................................................................................	199
W7220 JADETM Y-Pack Table .......................................................................................................................................	203
Section 18 - Appendix ...............................................................................	207
Glossary.........................................................................................................................................................................	207
Accessories for the M74XX Series Actuators ................................................................................................................	210
Accessories for the W7220 JADETM Economizer Module .............................................................................................	211

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Section 1 - Ventilation

Section 1 - Ventilation

DAMPER

EX.

AIR

DAMPER

O.A.

DAMPER	FILTERS
MIXED AIR SECTION	M23621

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Section 1 - Ventilation

Indoor Air Quality

The characteristics of the indoor climate of a building, including the gaseous composition, temperature, relative humidity, and airborne contaminants.

The Arab oil embargo of 1974 caused many building designers to begin implementing energy cost reduction measures. One of these measures was to seal up the building shell to reducing exfiltration of indoor air and the resultant heat loss. Energy costs were reduced but there was a significant negative side effect that was not detected until 1988:

Indoor Air Quality. Many buildings constructed prior to 1974 had sufficient leakage through poorly sealed windows and doors to adequately ventilate the building. Construction

methods used between 1974 and 1988 substantially reduced this leakage. As a result many buildings constructed between 1974 and 1988 are not adequately ventilated for the occupants.

As the energy costs continue to rise into the beginning of the 21st century, building managers are seeking ways to reduce the energy usage in new and existing buildings and continue to provide a healthy environment for the building occupants.

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Section 1 - Ventilation

Healthy Air

Building-Related Illness

A diagnosable illness with identifiable symptoms whose cause can be directly attributed to airborne pollutants within a building such as Legionnaires disease or hypersensitivity pnuemonitis.

The American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) are engineers in the HVAC industry who establish standards for the mechanical equipment used to heat, cool and ventilate buildings. Many local, state, national and international buildings codes are based on these standards. ASHRAE Standard 62.1,Ventilation for Acceptable Indoor Air Quality, is the ventilation standard for commercial buildings. It states “indoor air quality is acceptable when there are no known

contaminants at concentrations determined to be harmful to building occupants, as determined by cognizant authorities, and when a substantial majority (80% or more) of those persons exposed to the indoor air do not express dissatisfaction with its quality.” This standard sets minimum outdoor air ventilation rates and requires other measures intended to provide indoor air quality that is both acceptable to human occupants and minimizes negative effects on health.

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Section 1 - Ventilation

Symptoms of Inadequate Ventilation

Headaches

Dizziness

Drowsiness

Fatigue

Nausea

Eye Irritation

Respiratory Irritation

Causes of poor indoor air quality are not always caused by the design of the building. Poor or improper maintenance such as outdoor air dampers that are blocked open or completely closed, defective damper actuators or incorrectly set or malfunctioning controls may also cause inadequate ventilation. Many maintenance people respond to occupant complaints with only temperature in mind. If the room is within the acceptable temperature

range of 68 to 78°F. (20 to 26°C) it is perceived that no adjustments are necessary. The occupants may have many of the symptoms listed above but do not have the knowledge to request “open the outside air damper” or “increase the volume of supply air to this room.” It is incumbent on the knowledgeable HVAC service person to recognize inadequate ventilation when it is encountered.

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Section 1 - Ventilation

Indoor Air Ventilation Standards

ASHRAE is continually updating the ventilation standard (ASHRAE 62.1) to provide guidelines for design and maintenance of buildings. These standards are recommended guidelines only and are not legal requirements. However many state and local codes use the ASHRAE standards as the basis for building codes for new construction and building occupancy. They also form a basis for litigation in indoor air quality lawsuits.

Some measurements and gases referred to in the standards may not be familiar to the average person in the HVAC industry.

However the majority of the information contained in these standards is very clearly stated. Everyone in the HVAC industry should be knowledgeable about the contents of these standards.

The ventilation standard states a minimum outdoor air ventilation rate required per person per type of environment in Cubic Feet per Minute (cfm). The ventilation requirement varies between occupied and unoccupied periods. Outdoor air dampers are set to a minimum position based on the maximum occupancy level for the space. To save energy the ASHRAE 62.1 standard also allows ventilation to be based on a CO2 sensor input

that determines occupancy. This is commonly referred to as CO2-based demand control

ventilation (DCV).

CO2 Based Demand Control

Ventilation

CO2 is a fairly dependable indicator of the

concentration of the odorous bioeffluents exhaled by human beings. Therefore we can use CO2 concentration levels in a space to

determine the human occupancy and reduce

outdoor air intake when the space is not occupied to the maximum design occupancy level. CO2-based DCV is an energy

conservation measure; its purpose is to reduce outdoor air intake rates and the energy required to condition the outdoor air when spaces are not occupied at maximum design densities.

For those who do not want to read an engineering standard, ASHRAE offers a user manual that:

•offers information on the intent and application of Standard 62.1

•provides sample calculations and examples.

•provides useful reference materials.

•gives guidance to building operation and maintenance personnel.

Standard 62.1 Ventilation for Acceptable Indoor Air Quality

(ANSI Approved)

The Standard and User's Manual can be ordered from:

ASHRAE Publications Sales 1791 Tullie Circle, N.E. Atlanta, GA 30329 or

www.ashrae.org

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Section 1 - Ventilation

Energy Standards

There are four ASHRAE standards that affect energy use in buildings: Standard 90.1, Standard 90.2, Standard 100 and Standard 189.

Standard 90.1 Energy Efficient Design of New Buildings covers all buildings except low-rise residential for new design and build. It has been used for all buildings in the past due to the lack of detail in Standard 100.

Standard 90.2 Energy Efficient Desin of New Low-Rise Buildings covers low-rise residential buildings and has lacked detail in the past.

Standard 100 Energy Efficiency in Existing Buildings is the energy standard for existing buildings including residential. It was revised in 2012 to include compliance requirements, energy use analysis methods and energy targets, operation and maintenance and energy audit requirements for existing buildings for energy efficiency. There is also an extensive list of Energy Efficiency Measures that can be incorporated into existing buildings for energy efficiency.

Standard 189 Design of High-Performance Green Buildings except Low-Rise Residential Buildings – developed in conjunction with the US Green Buildings Council that goes beyond the requirements of Standard 90.1 for “green” buildings.

The standards are used as the basis for many federal, state and local jurisdictions as the energy code. If a state does not use the ASHRAE standards for the basis of the codes, they will use the International Energy Code Council (IECC) code.

In addition to the standards, ASHRAE has developed a series of publications designed to provide recommendations for achieving energy savings over the minimum code requirements of Standard 90.1 The guides were developed in collaboration with The American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IES), the US Green Building Council (USGBC) and the U.S. Dept of Energy (DOE). All guides are free for download at the ASHRAE website.

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Section 1 - Ventilation

Ventilation Requirements

Ventilation is defined as the process of bringing outside air into a building. The four major reasons for ventilation are:

1.To ensure a healthy atmosphere for the occupants. Ventilation is used to dilute indoor contaminants and provide fresh air for breathing.

2.To pressurize the building. Positive pressure inside a building prevents infiltration of unconditioned and unfiltered outside air through openings.

3.To provide atmospheric cooling. Bringing in cool outside air is more energy efficient and less costly than using mechanical cooling equipment.

4.To replace air that is being exhausted. The term for this is make-up air. Whenever air is exhausted, replacement air must be provided.

DAMPER

EX.

AIR

DAMPER

O.A.

DAMPER	FILTERS
MIXED AIR SECTION	M23621A

The air controls in the mixing section of a HVAC unit are used to maintain a minimum ventilation volume at all times. This is in addition to controlling the dampers for atmospheric cooling.

Determining the amount of ventilation required for a space is probably one of the hardest tasks an engineer faces in the design of the

ventilation system. Section 6 of ASHRAE 62.1 offers two procedures designers can use to determine ventilation rates, the Ventilation Rate Procedure (VRP) and the Indoor Air Quality Procedure (IAQP).

The VRP method is based on typical spaces and usage, the rates are intended to dilute and exhaust bioeffluents from occupants and building contaminants to satisfy the 80% of the occupants of the space. There are two sources of contaminants in a space that ventilation is intended to reduce: Occupants and their activities (e.g., use of office equipment) and Off-gassing from building materials. The ventilation rate in the breathing zone (Vbz) required for both people related

sources (Vp) and building related sources (Va) is:

Vbz = Vp + Va

Vp and Va both have two components; Vp is the number of people in the space (Pz) times the occupant comfort factor Rp (minimum

ventilation rate determined by extensive studies for occupant comfort based on activity level in the space) and Va is the area of the

space (Az) times the building component factor Ra (minimum ventilation rate

determined by extensive studies for occupant comfort based on type of space). Therefore ventilation required in the breathing zone becomes:

Vbz = RpPz + RaAz

Rp and Ra values are found in ASHRAE 62.1

User’s manual (Table 6-A) and ASHRAE 62.1 Standard.

The outdoor air or recirculated air may be cleaned using a filter or air cleaner but the outdoor air ventilation rates cannot be reduced below the rate determined by the above formula.

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Section 1 - Ventilation

The IAQP method is used for spaces where the designers target a specific contaminant and control the concentration level of the contaminant. This method has two requirements: Maintain concentration of specific contaminant(s) below target concentration limits and achieve a design target of perceived indoor air quality acceptability. The IAQP method allows ventilation rates to be lower than the rates required by the VRP method if it can be demonstrated the resulting air quality can meet the required criteria.

The IAQP procedure has 4 steps:

•Identify the contaminants of concern.

•Determine acceptable concentration of contaminant(s).

•Specify the perceived indoor air quality criteria.

•Apply an acceptable design approach to achieve the performance criteria.

Additional information on ventilation and the two methods used to determine the ventilation rates can be found in ANSI/ASHRAE Standard 62.1 and in the User’s manual for ANSI/ ASHRAE Standard 62.1. Both documents are available on the ASHRAE website at http://resourcecenter.ashrae.org/store/ashrae/

Example using the VRP method: Office space of 6600 sq. feet with maximum occupancy of 7

persons per 1000 ft2.

Vbz = RpPz + RaAz where Rp = 5 cfm per person

(Table 6-A ASHRAE 62.1 User’s Manual) Pz = 7 person per 1000 ft2 x Az

Ra = 0.06 cfm per ft2

(Table 6-A ASHRAE 62.1 User’s Manual)

Az = 6600 ft2.

Vbz = 5 ft3 / min/person x 7 persons/1000 ft2 x

6600 ft2 + 0.06 ft3/ min/ft2 x 6600 ft2 = 231 cfm + 396 cfm

=627 cfm

For a single zone system VOT (outdoor ventilation) is the same as Vbz. For multiple

zone systems a zone air distribution system effectiveness (E) factor needs to be used in the calculation of the VOT. See ASHRAE

Standard 62.1 for method.

In our example during maximum occupancy the ventilation is 627 cfm. When the occupancy rate is less than the maximum occupancy, the ventilation rate can be adjusted to a lower occupancy and the ventilation increased as the CO2 level in the space increases. This can be done following these steps:

•Calculate the VOT.

•Use Vbz = RpPz + RaAz, where Pz = 0. This is the new ventilation rate Vat (the area building based component).

•Add a CO2 sensor to the space.

•Adjust the CO2 maximum to the Vbz (for maximum occupancy).

•Adjust the minimum position for occupancy for Va.

In our example the Vbz ventilation is 627 cfm and the minimum position (Va) is 396 cfm. Using a CO2 sensor for Demand Control

Ventilation, the new minimum position is set for 396 cfm and the maximum damper position for occupancy ventilation is 627 cfm. When one person enters the space or the commercial thermostat goes into occupancy mode, the outdoor air dampers will open to bring in 396 cfm of outdoor air. As space occupancy increases, the CO2 level will

increase and the outdoor air dampers will modulate open to the maximum of 627 cfm of outdoor air.

NOTE: When the commercial thermostat calls for free cooling using an economizer, the dampers are still allowed to override the DCV maximum position for ventilation and open the damper 100% open for maximum free cooling.

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Section 1 - Ventilation

Air Handler Control Loops

	DAMPER
EX.	RETURN AIR
AIR	FROM ROOM

	DAMPER	HEATING COIL
O.A.	MIXED			SUPPLY
	AIR
				AIR TO
				BUILDING
DAMPER	FILTERS	COOLING COIL	FAN
	MIXED AIR	CONDITIONING	FAN	TERMINAL
	SECTION	SECTION	SECTION	SECTION
				M23889A

There are typically four sections of an air handler. The Mixed Air Section is where return air and outside air are combined (mixed). Note some systems’ fans may be 100% return air or 100% outside air and will not have a mixed air section.

The Conditioning Section commonly contains filtration, heating, cooling and humidification. The filters and heating and cooling coils are located in the conditioning section of the air handler.

In the Fan Section on the air handler shown there is a supply fan. On other air handlers there may be a return or exhaust fan. The supply fan on this unit is referred to as a pullthrough because it is located on the outlet of the coils. If it were located in front of the coils then it would be a push-through fan.

The Terminal Section is composed of all the components between the central fan and the zones.

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Section 1 - Ventilation

Basic Economizer Control

DAMPER
EXHAUST	RETURN AIR
AIR	FROM ROOM
	DAMPER
DAMPER	H705
	ENTHALPY
MOTOR	CONTROL
	DAMPER
	LINKAGE
OUTSIDE
AIR	SUPPLY
	AIR TO
	BUILDING

		F	110	120 130
		100		140
				15
		80		16
80	100	70	60	170
				180
		120
60
	40	140
	°F

PROPORTIONAL
MINIMUM POSITION
CONTROL FOR	ECONOMIZER TWO-POSITION
OUTSIDE AIR	HIGH LIMIT. CLOSES OUTSIDE
DAMPERS	AIR DAMPERS TO MINIMUM WHEN
	OUTSIDE AIR TEMPERATURE
	IS HIGHER THAN 70˚F (21 C)

F	110	120 130
100		140
		15
80		16
70	60	170
		180

PROPORTIONAL MIXED

AIR CONTROLLER.

SETPOINT 55˚F (13 C)

M23916A

Shown is the most basic temperature based economizer control configuration. An averaging element mixed air controller with the sensing element is located in the duct before the cooling or heating coils and maintains the mixed air at 55°F (13°C). A two position limit controller with sensing element in outdoor air is used to close the outside air dampers to a minimum position if the outdoor air temperature is too warm to use for cooling.

There is a minimum position control on most air handlers. The function of this control is to ensure proper ventilation. The control provides adjustable damper positioning between 0 and 100%. The outdoor damper position must be set for minimum ventilation requirements based on building occupancy as defined by state or local code.

NOTE: A setting of 25% does not produce 25% airflow because the flow through dampers is nonlinear.

It is important to know how much outside air is being brought into a building through the outdoor dampers on the air handlers. When the return and mixed air temperatures can be measured there is a formula used to calculate the settings that will provide the desired quantity of outside air.

Using the formula Vbz = Vp we know the total ventilation and volume required. A second formula is used to calculate the mixed air temperature when the outside air temperature, the return air temperature and the required percentage of outside air are known.

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Section 1 - Ventilation

Mixed Air Formulas

“OA”
	“MA”
	MIXED
C7400S	AIR
SENSOR	SENSOR
	“RA”
	MS3103
	ACTUATOR
	ECONOMIZER	COMMERCIAL
		THERMOSTAT
		M23917A

	Return Air	_	Mixed Air
	Temperature		Temperature	x 100% =	Volume (%) of
					Outside Air
	Return Air	_	Outdoor Air
	Temperature		Temperature

Formula for Measuring the Percentage of Outside Air in an Air Handler.

This formula is used to determine the percentage of outside air (by volume) being brought into a building from the outside. The OA dampers can be adjusted by measuring the MA, OA and RA to balance the correct Vbz. It is a test that should be conducted

during routine maintenance to ensure that the

correct percentage of ventilation is being provided. Note the fan must be running with the panels on the unit to take these measurements. Drill a hole in the side of the unit and insert temperature probe to measure the MA temperature. The hole must be sealed when measurements are completed.

% of

% of

Return Air

Outside Air

Temperature

X Return

+

X

Outside

=

Temperature

Temperature

of Mixed Air

Air

Air

Formula for Adjusting the Minimum Position Control.

This formula is used to make adjustments to the mixed air controls. In ASHRAE 62.1 there are two components of the percent of outdoor air ventilation required, the human component and the buildings effluent component. The rates in the standard are based on the type of human activity normally performed in the building. For example: the base rate for office buildings is 5 cfm per person and the building

effluent rate is 0.06 cfm per square foot of space. Initially only two temperatures are measured, return and outside air. The minimum position control is then adjusted until the mixed air temperature is equal to the result of the formula. For design requirements for CFM per person for all building types, refer to ASHRAE standard 62.1 section 6 and/or local or state building codes.

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Section 1 - Ventilation

Outside Air Percentage Chart

MIXED and RETURN AIR TEMPERATURES

	-29 C			-23		-18		-12		-7		-1		4		10		16		21		27		32		38		43		49 C
	-20 F			-10		0		10		20		30		40		50		60		70		80		90		100		110		120 F
	0%																															0%
%	10%																															10%	%
O	20%																															20%	O
U	30%																															30%	U
T	40%																															40%	T
S																																	S
I	50%																															50%	I
D																																	D
E	60%																															60%	E
A																																	A
	70%																															70%
I																																	I
R	80%																															80%	R
	90%																															90%
	100%																															100%
	-20 F			-10		0		10		20		30		40		50		60		70		80		90		100		110		120 F
	-29 C			-23		-18		-12		-7		-1		4		10		16		21		27		32		38		43		49 C

OUTSIDE AIR TEMPERATURE

M25274A

This chart can also be used for measuring the percentage of outside air on an air handler. The same three temperatures are measured per the formulas on the preceding page. Lines are drawn on the chart using a ruler. As with the formulas this chart is most effective if there is at least a 10 degree F difference between the return and outside air. This will typically require either a warm or cold day rather than moderate weather. It is more accurate to measure outside air percentage on a day

when the outside temperature is 10°F (-12°C) rather than on a day when it is 70°F (21°C). If the temperature difference between the return and outside air is only a few degrees, a small error in measurements can alter the results by as much as 50% using this method. If the temperature difference is 40 or 50°F (22 or 28°C) small errors in measurement do not substantially affect the results of the calculations.

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Section 1 - Ventilation

Example 1: Using the Outside Air Percentage Chart

		OUTSIDE							MIXED AIR TEMP										59 F (15 C)
						AIR																											RETURN AIR TEMP							70 F (21 C)
																			25 F (-4 C)
				CHART						OUTSIDE AIR TEMP
											MIXED and RETURN AIR TEMPERATURES
	-29 C					-23		-18			-12		-7		-1				4					10						16		21			27		32		38		43		49 C
	-20 F					-10		0			10		20		30				40											60									100		110		120 F
	0%																																			1		Measure the								0%
				Measure the mixed air																																		return air
	10%		temperature. This should be																																			temperature.								10%
%																								4																							%
				done in 4 or more locations and
O	20%		averaged.																																											20%	O
																																			Draw a line straight
U	30%																																5 down from the mixed air													30%	U
T								At the point of																																							T
	40%																																		temperature till it											40%
S						intersection draw a									6																				intersects the line that												S
I	50%					line to the left till the																													was just drawn.											50%	I
D					percentage of outside																																										D
E	60%							air is indicated.																																						60%	E
A																																															A
	70%																										3						Draw a line from the return													70%
I																																	air on top to the outside air on														I
R	80%																																the bottom.													80%	R
	90%																			2						Measure the outside air temperature.																				90%
	100%																																													100%
	-20 F					-10		0			10		20						40					50						60		70			80		90		100		110		120 F
	-29 C					-23		-18			-12		-7		-1				4					10						16		21			27		32		38		43		49 C

OUTSIDE AIR TEMPERATURE

M25275A

1.Measure the return air temperature.

2.Measure the outside air temperature.

3.Draw a line from the return air temperature to the outside air temperature.

4.Measure the mixed air temperature in multiple locations and determine the average.

5.Draw a line down from the mixed air temperature to the point where it intersects the first line.

6.Draw a line from the point of intersection to the outside air percentage on the left side of the chart.

According to the results from this chart this air handler is supplied with 26% outside air. If the total supply volume is 20,000 cubic feet per

minute (cfm) (566 m3/min) then:

0.26 X 20,000 cfm of total supply air equals

5,200 cfm of outside air (147 m3/min).

This indicates that when the measurements were done on this air handler the total volume of outside air in the mixed air was 5,200 cfm of

outside air (147 m3/min).

13	Honeywell Economizers 63-8594-02

Section 1 - Ventilation

Example 2: Use of Outside Air Chart on a Warm Day

		OUTSIDE							MIXED AIR TEMP									75 F (24 C)
					AIR																								RETURN AIR TEMP 71 F (22 C)
																		84 F (29 C)
			CHART						OUTSIDE AIR TEMP
										MIXED and RETURN AIR TEMPERATURES
	-29 C				-23			-18		-12		-7			-1			4			10				16			21						27			32				38				43		49 C
	-20 F					-10		0		10		20			30			40			50																90				100				110		120 F
	0%									Measure the return air											1																														0%
														temperature
%	10%																																				4														10%		%
	20%						Draw a line straight down from the																																												20%
O						mixed air temperature till it intersects																						5								Measure the mixed																	O
																																				air temperature.
U	30%									the line that was just drawn.																																									30%		U
																																				This should be
T																																																					T
	40%																																			done in 4 or more															40%
S																																																					S
																																				locations and
I																																																					I
	50%																																			averaged.															50%
												6
D																																																					D
E	60%							At the point of													3																														60%		E
A																																																					A
	70%						intersection draw a												Draw a line																						Measure the										70%
I							line to the left till											from the return																							outside air												I
R	80%						the percentage of											air on top to the																							temperature.										80%		R
	90%								outside air is										outside air on																						2										90%
										indicated.										the bottom.
	100%																																																		100%
	-20 F				-10			0		10		20			30			40			50				60			70						80							100				110		120 F
	-29 C				-23			-18		-12		-7			-1			4			10				16			21						27			32				38				43		49 C

OUTSIDE AIR TEMPERATURE

M25276A

The chart can also be used on a warm day when the outside air temperature exceeds both the return and the mixed air temperatures. The first line drawn will slant in

a different direction. Once again it is best to do this test when there is a minimum of 10 degrees F difference between the outside and return air.

Honeywell Economizers 63-8594-02

14

<![if ! IE]>

<![endif]>Section 1 - Ventilation

			<![if ! IE]> <![endif]>RETURN AIR TEMP
<![if ! IE]> <![endif]>Air Percentage Chart
		<![if ! IE]> <![endif]>MIXED AIR TEMP	<![if ! IE]> <![endif]>OUTSIDE AIR TEMP
<![if ! IE]> <![endif]>Outside		<![if ! IE]> <![endif]>OUTSIDE	<![if ! IE]> <![endif]>AIR CHART
<![if ! IE]> <![endif]>Extra

MIXED and RETURN AIR TEMPERATURES

		-29 C			-23		-18		-12		-7		-1		4		10		16		21		27		32		38		43		49 C
		-20 F			-10		0		10		20		30		40		50		60		70		80		90		100		110		120 F
		0%																															0%
	%	10%																															10%
	O	20%																															20%
	U	30%																															30%
	T	40%																															40%
	S
	I	50%																															50%
	D
	E	60%																															60%
	A
		70%																															70%
	I
	R	80%																															80%
		90%																															90%
		100%																															100%
		-20 F			-10		0		10		20		30		40		50		60		70		80		90		100		110		120 F
		-29 C			-23		-18		-12		-7		-1		4		10		16		21		27		32		38		43		49 C

OUTSIDE AIR TEMPERATURE

%

O U T S I D E

A

I

R

<![if ! IE]> <![endif]>M25277A	<![if ! IE]> <![endif]>Economizers 63-8594-02
	<![if ! IE]> <![endif]>Honeywell

<![if ! IE]>

<![endif]>15

Section 1 - Ventilation

Example 3: Minimum Ventilation Adjustment

DAMPER EXHAUST

AIR

RETURN AIR

73˚F (23 C)

DAMPER

OUTSIDE AIR

30˚F (-1 C)

M23910

1.Specifications:

Office space - 100,000 ft2

Air handler capacity 20,000 cfm (566 m3/min.)

People in area - 250

2.Ventilation (VOT) required:

=250 x 5 cfm + 0.06 cfm/ft2 x 100,000 ft2

=1250 cfm + 6000 cfm

=7250 cfm

Where Vat = 0.06 cfm/ft2 x 100,000 ft2. Therefore Vat = 6000 cfm

3.Ventilation percentage:

7250 cfm (205.3 m3/min)/20,000 cfm

(570 m3/min)

VOT maximum position= 36%

6000 cfm (169.9 m3/min)/20,000 cfm

(570 m3/min)

VOT Minimum position= 30%

4.Measure the return air temperature: 73°F (23°C).

5.Measure the outside air temperature: 30°F (-1°C).

This example shows a procedure for adjusting the DCV maximum and minimum positions.

Honeywell Economizers 63-8594-02

16

Section 1 - Ventilation

OUTSIDE AIR

30˚F (-1 C)

+

S

RETURN AIR

73˚F (23 C)

FILTERS

SUPPLY

AIR

SUPPLY OR	COILS	FAN
MIXED AIR
SENSOR
COMMERCIAL
THERMOSTAT

ADJUST THIS SETTING UNTIL THE MIXED AIR IS 62.5˚F (17 C)

									M23918A
	Return Air		% of		Outside Air		% of		Temperature
		X	Return	+		X	Outside	=
	Temperature				Temperature				of Mixed Air
			Air				Air

6.Use the mixed air temperature formula or the graph to determine the Demand Control Ventilation maximum MAT:

Temperature of

73°F (23°C) X

64%

+

30°F (-1°C) X

36%

=

Mixed Air

46.7°F (8.2°C)

+

10.8°F (-11.8°C)

57.5°F (14.2°C)

7. Use the mixed air temperature formula or the graph to determine the minimum position MAT:

Temperature of

73°F (23°C) X

60%

+

30°F (-1°C) X

30%

=

Mixed Air

43.8°F (8.2°C)

+

12°F (-11°C)

55.8°F (13.2°C)

8.Close the outside air dampers. The method used for this depends upon the controller being used.

9.When using analog economizers, turn the

DCV maximum position control (pot) until the measured mixed air temperature is

57.5°F (14.2°C). When using the JADETM controller, go to the set point menu and adjust the Vent max setting and the up and down arrows on the keypad.

10.Mark this setting on the control as being

36% outdoor air.

11.Close the outside air dampers. On the analog economizers, turn the minimum position control (pot) until the measured mixed air temp is 55.8 °F (13.2°C). When

using the JADETM controller, go to the set point menu and adjust the Vent min setting using the up and down arrows on the keypad.

12.Mark this setting on the control as being 30% outdoor air.

17	Honeywell Economizers 63-8594-02

Section 1 - Ventilation

Example 4: Ventilation Review Questions

DAMPER EXHAUST

AIR

RETURN AIR

68˚F (20 C)

30,000 CFM

(849 M3 MIN.)

OUTSIDE AIR

21˚F (-6 C)

1.Specifications:

Office space - 200,000 ft2.

Air handler capacity - 30,000 cfm (849 m3/min)

People in area - 350

2.Ventilation required:

=350 x 5 cfm per person + 0.06 cfm/ft2 x

200,000 ft2

=1750 cfm + 12,000 cfm

=13750 cfm

3.Ventilation percentage:

13750 cfm (389.4 m3/min)/30,000 cfm

(849 m3/min)

M23920

4.Measure the return air temperature: 68°F (20°C)

5.Measure the outside air temperature: 21°F (-6°C)

This is the air handler for an office building with 350 people maximum occupancy. Complete the required steps in the procedure to adjust the controls for the correct volume of ventilation.

Honeywell Economizers 63-8594-02

18

Section 1 - Ventilation

RETURN AIR

68˚F (20 C)

FILTERS

OUTSIDE AIR

21˚F (-6 C)

+

S

SUPPLY OR

MIXED AIR

SENSOR

CONTROLLER

COMMERCIAL

THERMOSTAT

SUPPLY

AIR

ADJUST THIS SETTING UNTIL THE MIXED AIR IS ___˚F (___ C)

M23919B

Return Air	X	% of	+	Outside Air		X	% of		=	Temperature
Temperature		Return Air		Temperature			Outside Air			of Mixed Air
6. Use the mixed air temperature formula or the graph:
68°F (20°C)	X	____%	+	21°F (-6°C)	X		____%	=	Temperature of
										Mixed Air
_____°F (____°C)			+	_____°F (_____C)					_____°F (____°C)

NOTE: Note use this formula to determine DCV maximum MAT and Minimum position MAT.

7.Close the outside air dampers to the minimum position.

The method used for this depends upon the controller being used.

8.On analog economizers, turn the DCV maximum control (potentiometer) until the measured mixed air temperature is

_____°F (_____°C). When using the JADETM controller, go to the set point

menu and adjust the Vent max setting using the up and down arrows on the keypad.

9.Mark this setting on the control as being 36% outdoor air.

10.On analog economizers, turn the minimum position until the measured mixed air temperature is _____°F

(_____°C). When using the JADETM controller, go to the set point menu and adjust the Vent min setting using the up and down arrows on the keypad.

11.Mark this setting on the control as being

_____% outdoor air.

12.Restore all settings and setpoints.

19	Honeywell Economizers 63-8594-02

Section 1 - Ventilation

Economizer Cycle Definition

ECONOMIZER CONTROLLER

YES

SINGLE STAGE COOLING

OUTSIDE

AIR COOL?

OPEN OUTSIDE

AIR DAMPER

NO

FIRST

STAGE COOL

Y1

MECHANICAL

SECOND COOL 1

Y2 STAGE COOL

COMMERCIAL THERMOSTAT

COMPRESSOR

M13816A

On a First Call for Cooling From Commercial Thermostat (Y1)

Controller signal is routed to the economizer logic module.

IF THE OUTDOOR AIR IS SUITABLE FOR FREE COOLING:

With analog economizers the actuator modulates the outdoor damper open until the room temperature is cool enough to satisfy the call for cooling and maintain the mixed or discharge air between 50 and 55°F (10 and

13°C). With the JADETM controller the actuator modulates the OA damper open to maintain the MAT setpoint. The MAT default is 53F with a 2F differential. The MAT setpoint can be changed in the menu using the up and down

arrows on the JADETM.

When the mixed or discharge air is between 50 and 55°F (10 and 13°C) the actuator will hold damper position with analog

economizers, with JADETM the actuator will

hold the temperature between -1F and +1F of the MAT setpoint. For example if the MAT is set to 53F, the damper will hold between 52F and 54F.

When the mixed or supply air goes below 50°F (10°C) the damper is modulated towards

closed (52°F for JADETM in our example).

When the mixed or supply air goes above 56°F (13°C) the damper is modulated towards

open (54°F for JADETM in our example).

For the analog economizers the MAT setpoint is not adjustable, the range can be changed

using external resistance. For the JADETM, the MAT is adjustable between 38°F and 70°F.

IF THE OUTDOOR AIR IS NOT SUITABLE FOR FREE COOLING:

The first stage of the cooling compressor is turned on and the dampers are set to minimum for occupancy requirements (Vat if

using DCV, VOT if no DCV).

Honeywell Economizers 63-8594-02

20

Section 1 - Ventilation

Single and Two Stage Cooling With Economizer

ECONOMIZER CONTROLLER

YES

TWO STAGE COOLING

OUTSIDE

AIR COOL?

OPEN OUTSIDE

AIR DAMPER

NO

		FIRST
	Y1	STAGE COOL
		MECHANICAL
		COOL 1
		SECOND
	Y2	STAGE COOL
		MECHANICAL
	COMMERCIAL THERMOSTAT	COOL 2
		COMPRESSORS
		M13817A

On a Call for Second Stage Cooling

Controller signal is routed to the economizer logic module.

IF THE OUTDOOR AIR IS SUITABLE FOR FREE COOLING AND THE OUTSIDE AIR DAMPERS ARE OPEN:

The economizer logic turns on the first stage of mechanical cooling for the second stage of cooling required by the commercial thermostat. With JADETM the actuator drives the OA damper wide open to try to satisfy the call for second stage of cooling. If OA dampers are 100% open and call for second stage is not satisfied then the JADETM will turn on the second stage mechanical cooling and the OA damper will remain wide open.

NOTE: JADETM has an option in the

Advanced setup menu "STG3 DLY" which is a delay after the stage 2 for

cooling has been active for a programmed amount of time. If the space has not been satisfied after the programmed amount of time, the JADETM turns on the 2nd stage of mechanical cooling to allow 3 stages of cooling, 1 economizer and 2 mechanical. This feature can also be turned off.

IF THE OUTDOOR AIR IS NOT SUITABLE FOR FREE COOLING:

The first stage cooling compressor is on, and the logic module turns on the second stage of mechanical cooling.

NOTE: A commercial thermostat with a minimum of two stages of cooling is required. The first stage must be available for economizing if outside air is suitable.The OA dampers must be opened completely on a second call for cooling before the mechanical cooling is turned on.

21	Honeywell Economizers 63-8594-02

Section 1 - Ventilation

Honeywell Economizers 63-8594-02

22

Section 2 - Enthalpy Theory And Controllers

Section 2 - Enthalpy Theory And Controllers

50 BTU/LB

116 k-J/kg

R H

9

0

45 BTU/LB

H

F

(

32

C)

104.5 k-J/kg

%

W

E

0

0

T

B

U

40 BTU/LB

N

- 1

L

B

92.8 k-J/kg

I

O

8

5

F

T

(2

35 BTU/LB

9

A

C)

R

H

W

ET

81.4 k-J/kg

U

B

T

U

S

A

L

B

30 BTU/LB

8

H

0

F

69.7 k-J/kg

R

(

2

7

%

C

25 BTU/LB

6

0

)

W

E

T

B

58 k-J/kg

R

7

%

5

F

0

(

20 BTU/LB

5

2

4

C

46.4 k-J/kg

H

)

W

E

R

6

0

F

%

T

0

15

4

70

5

5

H

F

BTU/LB

(

2

34.8 k-

R

1

C

%

0

J/kg

5

L

B

3

W

E

H

6

5

L

%R

F

(

B

0

2

1

8

C

3

5

U

L

)

W

E

F

(

B

H

T

B

2

%

R

U

L

0

L

C

B

1

B

)

W

E

T

B

U

L

L

B

B

40 F

50 F

60 F

70 F

80 F

90 F

100 F

110 F

120 F

4 C

10 C

16 C

21 C

27 C

32 C

38 C

43 C

49 C

35 F

45 F

55 F

65 F

75 F

85 F

95 F

105 F

115 F

2 C

7 C

13 C

18 C

24 C

29 C

35 C

41 C

46 C

DRY BULB TEMPERATURES

M25280

23	Honeywell Economizers 63-8594-02

Section 2 - Enthalpy Theory And Controllers

The Psychrometric Chart

This is a psychrometric chart. To use the chart effectively the thermodynamic properties of air must be known. Some common terms are:

Dry Bulb Temperature

The temperature read directly on an ordinary thermometer.

Wet Bulb Temperature

The temperature read on a thermometer whose bulb is encased in a wet wick and with air blown across the wick at 900 ft. per minute

(274 meters per minute). The evaporation of the water causes the temperature to drop, this may also be referred to as the “evaporation effect.” When the temperature stops falling that is the wet bulb temperature. The sling psychrometer is a common instrument used to determine the wet bulb temperature although there are other methods now available.

Dry bulb and wet bulb are the two most readily measurable variables on the chart and when known can be used to determine all other properties on the psychrometric chart.

R

H

H

9

0

F

(

3

2

%

C)

W

E

0

0

T

B

U

N

-

1

L

B

O

I

8

5

F

T

(2

9

A

C

R

H

)

W

E

U

T

B

T

U

S

A

L

B

8

H

0

F

R

(

2

7

%

C

6

0

)

W

E

T

B

R

%

7

5

F

0

(

5

2

4

C

H

)

W

E

R

6

0

F

%

T

0

4

7

0

5

5

H

F

(

2

R

1

C

%

0

)

W

5

L

B

3

E

H

6

5

L

%R

F

(

B

0

2

1

8

C

3

5

U

L

)

W

E

F

(

B

H

T

B

2

%

R

U

L

0

L

C

B

1

B

)

W

E

T

B

U

L

B

L

B

40 F

50 F

60 F

70 F

80 F

90 F

100 F

110 F

120 F

4 C

10 C

16 C

21 C

27 C

32 C

38 C

43 C

49 C

35 F

45 F

55 F

65 F

75 F

85 F

95 F

105 F

115 F

2 C

7 C

13 C

18 C

24 C

29 C

35 C

41 C

46 C

DRY BULB TEMPERATURES

M25278

63-8594-02

Honeywell Economizers

24