Field Controls ventCool Instructions Manual

AUTOMATIC VENTILATION COOLING SYSTEM

Model: ventCool™

The Field Controls Healthy Home System™ ventCool™ is designed to be installed as part of the central HVAC forced-air duct system of
a home or other suitable building, in areas where outdoor conditions may exist to cool the building with outdoor air, such as California
climate zones 8 through 14.

California Energy Code (CEC) Title 24 provides large building energy reduction credits for Central Fan Integrated Ventilation Cooling
Systems (see Title 24 Residential Compliance Manual section regarding HVAC Requirements, Alternate Systems). Similar in cost and
function to a Whole House Fan, the Healthy Home System™ Automated Ventilation Cooling System monitors indoor and outdoor
conditions day and night, and automatically provides 100% outdoor air ventilation for cooling whenever outdoor conditions allow.

ITEMS INCLUDED IN KIT:

3- ventCool™ Ventilation Cooling System Dampers of either 14”, 16”, 18”, or 20” diameter
1- Integrated Ventilation Relay Control (IVRC) Damper Control Module
3- 15 foot long Damper Cables with modular connectors
1- TrioMAC8-2025 ™ Media Air Cleaner
1- Venstar® T7850 Programmable Smart Thermostat with WiFi, touchscreen, and ventilation

cooling function
1- Venstar® ACC-TSEN Outdoor Temperature Sensor
1- 50 VA, 24 Volt Transformer, junction box mounted

OPTIONAL COMPONENTS:

Healthy Home System™ Components for optional Fresh Air Mechanical Ventilation:

• HHSC+ Ventilation Control

• FAD Fresh Air Damper

• Relief Duct Termination/screened cap

T Sensor temperature-sensing damper controller

COMPONENTS NOT INCLUDED:

•Outdoor Air Intake Ventilation Cooling Termination(s)

•Ductwork,  ttings, 24V wiring & associated hardware

•Inlet termination for optional Fresh Air Mechanical Ventilation

•Air Handler and other HVAC system components

READ THESE INSTRUCTIONS CAREFULLY AND COMPLETELY BEFORE PROCEEDING WITH THE INSTALLATION.

This device MUST be installed by a quali ed agency in accordance with the manufacturer's installation instructions. The de nition of
a quali ed agency is: any individual,  rm, corporation or company which either in person or through a representative is engaged
in, and is responsible for, the installation and operation of HVAC appliances, who is experienced in such work, familiar with all the
precautions required, and has complied with all the requirements of the authority having jurisdiction.

Installed By: Phone:

Please retain these instructions after installation.

Installation Date:

www. eldcontrols.com

NOTE

FIG 1

The system consists of an outdoor air intake duct with Ventilation Cooling Damper (outdoor air intake not
included), a Return Air Damper, a Relief/Exhaust Damper (screened termination cap not included), a
damper control module (IVRC), and smart thermostat with outdoor air temperature sensing and free cooling mode
capabilities. All outdoor air coming into the building must be  ltered by a media air cleaner such as the Field Controls
Trio™, which when installed as shown serves as the HVAC system  lter for extended dust and particulate removal.

The system dampers are automatically controlled by the IVRC Damper Control Module, which is in turn controlled
by the smart thermostat. The smart thermostat determines when the Automatic Ventilation Cooling mode should
occur, based on indoor and outdoor temperature conditions.

Optional items not included are components for year-round fresh air mechanical ventilation, which may be directly
integrated into the ventCool™
ASHRAE 62.2: FAD Fresh Air Damper, HHSC+ Ventilation Control, and optional T-Sensor Damper Control.

NOTE: : When the HVAC system is in “Free Cooling Mode”, the HVAC fan is enabled and the heating and mechanical
cooling functions of HVAC system is disabled.

system for the purpose of meeting mechanical ventilation code requirements of

DESCRIPTION OF OPERATION:

When the smart thermostat senses a need for indoor cooling, and outdoor conditions are suitable (refer to System
Setup section), the ventCool™ Ventilation Cooling Mode will be activated. At all other times, the smart thermostat
will command normal operation of the mechanical HVAC system, for both heating and mechanical cooling, and the
ventCool™ system will be de-activated.

page 2

When Ventilation Cooling Mode is

NOTE:

activated, the following actions occur:

1. Thermostat displays “Free Cooling” on the Home
Screen, and sends a 24 volt signal to the IVRC damper
control module to activate ventilation cooling.

2. The IVRC commands the Ventilation Cooling Damper
to open, the Relief Damper to open, and the Return
Damper to close.

3. When the dampers respond with appropriate signals,
the IVRC will then allow the HVAC system fan to run,
bringing outdoor air into the building, and allowing
return indoor air to exhaust into the attic area and exit
the building via attic ventilation openings. The Relief
Damper serves to increase the outdoor air exchange
rate and cool the attic area.

4. The IVRC display will appear as shown in FIG 2.

When Ventilation Cooling Mode is
de-activated, the following actions occur:

FIG 2

1. Thermostat cuts o the 24 volt Ventilation Cooling signal
to the IVRC damper control module. Thermostat will
display either “System Idle” or “Cooling”, depending on
current conditions.

2. The IVRC commands the Ventilation Cooling Damper
to close, the Relief Damper to close, and the Return
Damper to open.

3. When the dampers respond with appropriate signals to
the IVRC, normal operation of the HVAC heating and
mechanical cooling will be allowed.

4. The IVRC display will appear as shown in FIG 3.

FIG 3

With optional Year-Round Fresh Air Mechanical Ventilation:

Mechanical fresh air ventilation may be required by code, for the purpose of providing adequate fresh air
ventilation throughout the year. The Field Controls ventCool™ is designed to be fully compatible with the Field
Controls Healthy Home System™ HHSC+ ventilation controller when installed as directed with a dedicated FAD fresh
air damper.
mechanical ventilation, due to the large volume of outdoor air that may potentially be brought in during periods of
adverse weather conditions.

Normal, independent operation of the HHSC+ and dedicated damper is allowed when the ventCool™ ventilation
cooling mode is de-activated; see the HHSC+ instructions for operation details. When the ventCool™ ventilation
cooling mode is activated, it will continue to allow the HHSC+ to control the dedicated damper according to HHSC+
programming; cycling of the dedicated damper may occur but will have no signi cant impact on ventilation cooling.

NOTE: It is not recommended to use the Ventilation Cooling damper for the purpose of routine fresh air

If a mechanical ventilation system by another manufacturer is intended to be installed as part of the HVAC system,
refer to the manufacturers’ instructions to ensure proper operation of the overall system. Field Controls cannot
guarantee proper operation if another manufacturer’s ventilation system is installed.

page 3

SIZING, SEALING, AND INSULATION OF COMPONENTS AND DUCTWORK:

Sizing of Dampers and Ducts:

return plenum sizing

The recommended design velocity in such ductwork is 600 feet/minute or less

Insulation and Sealing of Dampers and Ductwork:

sealed

insulated

IMPORTANT: Ensure that insulation, draw ties, tape etc. do not interfere with motion of the damper shafts.

Ventilation Cooling Outdoor Air Intake Sizing:

Outdoor Air Inlet Termination(s):

Outdoor air intakes may be of the following types, with the given considerations:

Through the roof/false chimney:

Gable end:

Hip extension/dormer:

Roof Eyebrow:

So t vents:

Relief Outlet Termination:

Sizing of Dampers and Ducts: All three ventCool™ dampers and associated  ttings and ductwork should
be sized as large or larger than trunk return duct sizes as required by applicable local HVAC code, ACCA Manual D as
applicable, or the authority having jurisdiction, as required for
outdoor air intake portion of the ventCool™ system essentially becomes a substitute for the return trunk duct
or plenum when it is activated.
Separate mechanical ventilation systems and associated ductwork installed for the sole purpose of meeting
ventilation codes and standards (such as ASHRAE 62.2) should be sized, sealed and insulated according to the
manufacturer’s installation instructions.

Insulation and Sealing of Dampers and Ductwork: The Ventilation Cooling Damper, outdoor air intake
ductwork, and return plenum/trunk ductwork downstream of the outdoor air intake duct junction should
be sealed and insulated as required by applicable local HVAC code for fresh air inlet ducts for the space in
which they are located, or as otherwise required by applicable local code. The Relief Damper and relief
ductwork should be
the space in which they are installed, or as otherwise required by local code or authority having jurisdiction.

IMPORTANT: Ensure that insulation, draw ties, tape etc. do not interfere with motion of the damper shafts.

Ventilation Cooling Outdoor Air Intake Sizing: refer to California Energy Code (CEC) Title 24 Residential Compliance
Manual for guidelines for installation and sizing. The total open area of the outdoor air intake(s) must be of
su cient size for their type and design; air inlet openings are often the greatest factor a ecting pressure
loss and  ow rate in air ducts, and their characteristics must be taken into account in duct  ow calculations.

sealed and

The recommended design velocity in such ductwork is 600 feet/minute or less.

insulated as required by applicable local code for return trunk ductwork for

return plenum sizing. The Ventilation Cooling

INSTALLATION:

Outdoor Air Inlet Termination(s): Outdoor air intakes should be regarded and considered as forced air
inlets as described in National Fuel Gas Code ANSI Z223.1, NFPA 54, NFPA 31, ASHRAE 62.2 appendices, and
all applicable local codes. Intake termination shall be located away from possible sources of fumes and
contamination, such as appliance exhaust vents, gas meters, oil or gas storage tanks, garbage containers etc.
Outdoor air intakes should be located upwind of the attic vents or dedicated Relief Outlet Termination as much as
possible, to minimize cross-contamination of the intake with the relief air being exhausted from the building.

Outdoor air intakes may be of the following types, with the given considerations:

•

Through the roof/false chimney: roo ng systems may retain signi cant heat and may elevate the intake air
temperature above that of other types, especially if not su ciently elevated above the roo ine. Typically
the least a ected by wind loading although high winds may create a signi cant pressure loss depending
on design.

•

Gable end: wind loading may signi cantly a ect air  ow rates, depending on wind direction while the
system is active.

Hip extension/dormer: wind loading and roof heat may be factors, especially with a hip extension.

•

Roof Eyebrow: wind loading and roof heat may be signi cant factors.

•

So t vents: roof heat may be a factor if located on a downwind side of the building; also wind loading

•
may be a factor.

Multiple outdoor air intakes may be combined to provide adequate open area for air  ow while reducing the size
of the intakes.

Relief Outlet Termination: Maximum ¼” screen or mesh size is recommended for protection from animal/
debris intrusion. An attic location is highly recommended for cooling of the attic space and roof structure.
Refer to CEC Title 24 Residential Compliance Manual, Tables 4-20 and 4-21 for guidelines on ventilation of the
attic to outdoors. If an attic location is not feasible, termination locations as given for the outdoor air intake may
be preferred; if so, wind loading will tend to be an even more signi cant factor while roof heat is of lesser concern.

page 4

ventCool™ Ventilation Cooling, Return, and Relief Dampers:

ventCool™ Ventilation Cooling, Return, and Relief Dampers: All three dampers are identical in size and each may be

IVRC Damper Control Module:

Smart Thermostat Ventstar T 7850: I

Outdoor Temperature Sensor Venstar ACC-TSEN:

HHSC+ Fresh Air Ventilation Control (optional):

T-Sensor Damper Control (optional):

CAUTION: All connections to the

ventCool™

system and its components (except 120V/24V system
transformer) are to be nominal 24VAC. Ensure all wiring is properly supported and
installed; use strain reliefs where present and required by code.

WARNING: All wiring is to be installed and inspected in compliance with all local code require

ments of

the jurisdiction having authority.

WARNING: Ensure that all wiring connections to the

ventCool™

System do not exceed nominal 24VAC.

Connection to the ventCool™ system with di erent line voltages (power) will cause severe

component damage, electrical shock hazards, and potential  re hazard!

WARNING: Disconnect branch circuit for 24VAC transformer and all power sources to the HVAC

system before beginning installation!

used interchangeably as shown on the system diagram. The dampers may be installed vertically, horizontally, or at
an angle. Install with the damper shaft as close as possible to a horizontal (level) position as shown in FIG 4.:

FIG 4

IVRC Damper Control Module: The IVRC may be installed in an attic or mechanical room area, away from heat
sources such as vent connectors, chimneys and heating appliances (see Speci cations for max service temperature),
and in a dry and protected indoor location. Install the IVRC such that the relay status indicator lamps are visible, and
all wiring connections are accessible. Ensure that the wiring connections to the Smart Thermostat and HVAC system
do not exceed maximum wiring lengths and gauge limitations as given in their respective installation instructions.

Smart Thermostat Ventstar T 7850: Install the thermostat in the living space, in a location as recommended in the
thermostat ins tallation instructions included with the thermos tat. Refer to those ins tallation instructions fo r maximum
wiring lengths and gauge limitations. The complete installation manual is available online for free download at
www.Venstar.com.

Outdoor Temperature Sensor Venstar ACC-TSEN: Install the outdoor temp sensor according to the instructions
included with the sensor. Ensure that the sensor is not subjected to direct sunlight or other heat sources such as
appliance and dryer vents, etc.

HHSC+ Fresh Air Ventilation Control (optional): Refer to the installation instructions included with the HHSC+.
Attic installation in hot climates is not recommended; see the Speci cations section in the HHSC+ installation
instructions for maximum service temperature and other limitations.

T-Sensor Damper Control (optional): Refer to the installation instructions included with the T-Sensor. Install the
T-Sensor on the dedicated fresh air duct upstream of the FAD damper.

ELECTRICAL CONNECTIONS:

(Please refer to the appropriate wiring diagrams as shown below)

CAUTION: All connections to the

transformer) are to be nominal 24VAC. Ensure all wiring is properly supported and
installed; use strain reliefs where present and required by code.

WARNING: All wiring is to be installed and inspected in compliance with all local code require

the jurisdiction having authority.

ventCool™

system and its components (except 120V/24V system

ments of

WARNING: Ensure that all wiring connections to the

Connection to the ventCool™ system with di erent line voltages (power) will cause severe

component damage, electrical shock hazards, and potential  re hazard!

WARNING: Disconnect branch circuit for 24VAC transformer and all power sources to the HVAC

system before beginning installation!

page 5

ventCool™

System do not exceed nominal 24VAC.

Install 50VA 24VAC System Transformer:

Install 50VA 24VAC System Transformer: Following the instructions included with the transformer, install the

NOTE:

IMPORTANT:

The IVRC terminals CX and RX terminals (1 & 2) must ONLY be connected to the

ventCool™
system 24VAC transformer! ventCool™ power must be separate and independent from the HVAC 24V
control power. The HVAC system, thermostat, and ventCool™ system must be installed as shown in this
manual or equipment damage may occur! Connect ventCool™ System Dampers to the IVRC Damper Control Module.

Use the included modular damper cables to connect dampers to the IVRC (see  gures below). The
Dampers and IVRC have modular connectors to prevent miswiring and for ease of installation. The cables
have di erent connectors on either end, that mate to corresponding connectors on the IVRC and on the
damper motors. The damper cables are not speci c to any of the dampers and may be freely interchanged.
(HINT: Mark connector housing of each damper harness for identi cation purposes, when installation is complete.)

Connect IVRC Damper Control Module, Outdoor Temperature Sensor, and Smart Thermostat to HVAC System:

NOTE:

IMPORTANT: The thermostat terminal Y2 is the sole mechanical cooling output from the thermostat when
con gured for free cooling, as Y1 is used exclusively to control Automatic Ventilation Cooling. If the HVAC system has
multi-stage mechanical cooling, to utilize full capacity of the mechanical cooling system, con gure the HVAC
mechanical cooling system to operate with a single-stage input, refer to the HVAC equipment manufacturer’s
instructions regarding control by a single-stage thermostat. In some cases, this may require the use of an
installer-supplied delay-on-make timer to activate 2nd stage cooling.

transformer near the IVRC damper control module. Ensure the power is disconnected to the line voltage circuit that
will power the transformer, and connect the 120V side of the transformer to the line voltage. Connect the 24VAC
side of the transformer to the IVRC damper control module terminals CX and RX (IVRC terminals 1 & 2).

NOTE:

120V power must be maintained to the transformer at all times for proper operation of the ventCool™ system.

IMPORTANT:
system 24VAC transformer! ventCool™ power must be separate and independent from the HVAC 24V
control power. The HVAC system, thermostat, and ventCool™ system must be installed as shown in this
manual or equipment damage may occur! Connect ventCool™ System Dampers to the IVRC Damper Control Module.

Use the included modular damper cables to connect dampers to the IVRC (see  gures below). The
Dampers and IVRC have modular connectors to prevent miswiring and for ease of installation. The cables
have di erent connectors on either end, that mate to corresponding connectors on the IVRC and on the
damper motors. The damper cables are not speci c to any of the dampers and may be freely interchanged.
(HINT: Mark connector housing of each damper harness for identi cation purposes, when installation is complete.)

The IVRC terminals CX and RX terminals (1 & 2) must ONLY be connected to the

ventCool™

Ensure that the system dampers are connected to the correct connectors on the IVRC, depending on their
function. Refer to the system diagram and connector identi cation on the IVRC. Incorrect connections will not
damage the IVRC or dampers, but will cause incorrect operation of the ventCool™ system.
Damper cables may be extended up to 50 feet with 18 gauge wire. Make sure proper connections are made;
incorrect connections may damage the IVRC, 24V transformer, and/or system dampers.

FIG 5 FIG 6

Connect IVRC Damper Control Module, Outdoor Temperature Sensor, and Smart Thermostat to HVAC System:
Select the appropriate wiring diagram for the HVAC system type from the wiring diagrams (A through D), and wire
the IVRC, Outdoor Temperature Sensor, and Smart Thermostat into the HVAC system as shown.

NOTE: The IVRC is connected to the thermostat in place of the “Free Cooling Damper” as shown in the Venstar®
thermostat installation instructions diagram.

IMPORTANT: The thermostat terminal Y2 is the sole mechanical cooling output from the thermostat when
con gured for free cooling, as Y1 is used exclusively to control Automatic Ventilation Cooling. If the HVAC system has
multi-stage mechanical cooling, to utilize full capacity of the mechanical cooling system, con gure the HVAC
mechanical cooling system to operate with a single-stage input, refer to the HVAC equipment manufacturer’s
instructions regarding control by a single-stage thermostat. In some cases, this may require the use of an
installer-supplied delay-on-make timer to activate 2nd stage cooling.

page 6

page 7

page 8

page 9

page 10

System Setup Procedure:

Note:

WARNING: Before restoring power to the HVAC and

ventCool™

systems, check all wiring for

proper connections and voltages. All circuits must have appropriate circuit protection.

Verify Ventilation Cooling De-Activated Mode Operation:

WARNING: Before restoring power to the HVAC and
proper connections and voltages. All circuits must have appropriate circuit protection.

1. Remove the Venstar thermostat from its base, and make sure the outdoor temperature sensor is properly

connected to the thermostat. An electrical short in the sensor wiring or connections may cause failure of the
HVAC system control fuse or damage the system transformer.

2. Make sure the thermostat dip switches on the circuit board are set to the correct settings for the HVAC system

type. Refer to Venstar operations manual found at www. venstar.com

3. Carefully install the thermostat onto its base. Press  rmly around all outside edges.

4. Turn on power to the HVAC system, to power the thermostat and HVAC controls. Verify that the thermostat

powers up properly according to instructions.

5. At the Venstar thermostat, select “Free Cooling” from the “Installation Settings” menu, and con gure the

thermostat to enable “Free Cooling”; see “Free Cooling” section of thermostat instructions.
thermostat dip switches are con gured for a Heat Pump: the number of compressor stages must be set to 1 in
the “Heat & Cool Stages” menu, regardless of the number of cooling stages (see note in the Electrical Connections
of this manual). “Free Cooling” cannot be enabled if Compressor Stages is set to 2.

6. Set “Free Cooling” parameters on thermostat according to preference; see thermostat instructions section

regarding “Free Cooling”.

7. Exit the “Free Cooling” menu, and select “Sensor Settings” from the “Installation Settings” menu.

ventCool™

systems, check all wiring for

Note: If the

8. Select “Wired Sensor Use”, and select the “Outdoor Sensor” setting”.

9. Set remaining thermostat program and system parameters according to preference and HVAC system type.

10. Turn on power to the ventCool™ system 24V transformer. Depending on existing damper positions, some

dampers may open or close.

System Checkout Procedure:

Verify Ventilation Cooling De-Activated Mode Operation:

1. At the Venstar thermostat Home Screen, press the “Mode” button and select “O ”, to put the HVAC system on

standby.

2. Verify that the Return Damper reaches an open position within approximately 15 seconds, as shown in FIG 7

below:

FIG 7

page 11

3. Verify that the both the Ventilation Cooling Damper and Relief Damper reach closed positions within

ventCool™

ventCool™

IMPORTANT: Make sure to re-enable “Free Cooling”!

approximately 15 seconds, as shown below:

FIG 8

4. Verify that the IVRC damper control module indicator lamps are as shown in Figure 3.

5. At the Venstar thermostat Home Screen, press the Fan icon and select “On” to turn the HVAC system fan on.
Verify that the system fan operates properly.

6. At the Venstar thermostat, press the Fan icon and select “Auto”. The fan should stop operating.

Verify Ventilation Cooling Activated Mode Operation:

1. At the thermostat Home Screen, press the “Mode” button and select “O ”, to put the HVAC system on standby.

2. Enter the “Installation Settings” menu, select “Free Cooling” menu, and temporarily disable “Free Cooling”.

3. From the “Installation Settings” menu, select “Test Outputs”, and press the Cooling 1st Stage button.

4. Within a few seconds, the Y1 and G output indicators should illuminate, and the Y1 and G terminals should be
energized with nominal 24VAC. This should activate the
not been disabled, the Y1 indicator will not illuminate and Y1 terminal will not be energized.

5. Verify that the Return Damper reaches a closed position within approximately 15 seconds, as shown in Figure 8.

6. Verify that both the Ventilation Cooling Damper and Relief Damper reach open positions with approximately 15
seconds, as shown in Figure 7.

7. Verify that the IVRC damper control module output indicator lamps are illuminated as shown in Figure 2.

8. Verify that the HVAC system fan begins operating at the speed con gured for a fan call with Y1 (high speed is
recommended). Outdoor air should now begin being drawn into the house, and indoor air should be exiting
the Relief Damper duct termination cap, assuming all house doors and windows are shut.

9. Exit the Venstar thermostat “Test Outputs” menu, select “Free Cooling”, and enable Free Cooling Mode. The
ventCool™ system should become de-activated when exiting the “Test Outputs” menu.

ventCool™ active mode. Note: if “Free Cooling” has

IMPORTANT: Make sure to re-enable “Free Cooling”!

page 12

Verify Mechanical Cooling and Heating Operation (if installed):

“Installation Settings”

ventCool™

System Setup

ventCool™

IMPORTANT: The HVAC system may now be placed into the desired mode of operation!

HVAC

O

ventCool™

Intermittent operation:

Damper fails to open:

1 At the Venstar thermostat, in the

Cooling is enabled. Exit to the “Installation Settings” menu.

2. Select the “Test Outputs” menu, and press the Cooling 2nd Stage button. The Y2 and G indicators should
illuminate, and Y2 and G terminals should be energized.

3. Verify that the
section.

4. Verify that the HVAC mechanical air conditioning system operates properly. Keep in mind that when “Free
Cooling” is enabled, the thermostat will only call for mechanical cooling with Y2 and G, and Y1 will not be
energized.

5. If gas, electric, or heat pump heating is installed, return the thermostat to the Home Screen, set the system
mode to Heating, and set the thermostat to a setting that would create a heating call. Verify proper operation
of the heating system.

ventCool™ system becomes or remains de-activated, as described in this manual’s

Testing of the

IMPORTANT: The HVAC system may now be placed into the desired mode of operation!

“Installation Settings” menu, select “Free Cooling” and ensure that Free

System Setup

ventCool™ system is now complete!

Maintenance, Inspection and Cleaning

At the beginning of every heating or cooling season:

• Inspect the dampers for proper operation as directed in the System Checkout section of this manual.

Make sure the dampers are able to rotate freely without interference. Damper bearings and motor are
maintenance-free; no lubrication is required.

• Inspect all cables and wiring for possible damage by animals or human activity.

• Inspect the Outdoor Air intake and Relief Duct Termination Cap and clean if necessary. Remove any debris

or other items that may have accumulated. Remind all occupants to keep objects and contaminant sources
away from the intake and relief terminations.

• Inspect the Outdoor Air Temp Sensor and clean if necessary. Make sure it remains in a shaded area away

from any heat sources.

Troubleshooting

Damper Operation: For diagnostic purposes, temporarily turn the
at the Venstar thermostat. This should leave the
With the HVAC system o , damper cable connections may safely be swapped to those sockets that are ON
or OFF (as indicated by the IVRC control module indicator lamps), to easily check damper functions. Make
sure to return cable connections to their proper positions and turn the HVAC system back on when  nished.

• Inspect damper for mechanical binding or interference.

•

Intermittent operation: Wiggle the cable connector at the damper and the IVRC damper control module
while the system is calling for the damper to operate. If a bad connection is present, inspect and repair or
replace the damper cable, or damper motor assembly as required.

ventCool™ system powered and in the de-activated state.

HVAC system to

O from the Home Screen

•

Damper fails to open: Remove the cap from the damper motor. While the IVRC indicator lamp for the
speci c damper is illuminated, check for voltage from blue cable wire (orange circuit board wire) to white
cable wire (black circuit board wire). If nominal 24V is present and the damper will not open, replace the
damper motor assembly. If not, check cable connections as above.

page 13

•

Damper fails to close:

away from the round base

NOT

IVRC Damper Controller Operation:

Note:

No indicator lamps illuminated on IVRC:

ventCool™

No change in IVRC outputs and/or indicator illuminations when Ventilation Cooling should be activated by
the thermostat:

Venstar Thermostat and Outdoor Air Sensor:

at least three or more degrees F

below

at least two degrees F above

IVRC Damper Controller Operation:

The IVRC controls damper operation and permits a fan call on the G terminals to pass through, when the dampers
are in their correct state and responding properly. Outputs to each damper to open are indicated with a glowing
lamp corresponding to the damper cable socket for that damper. Each damper should be given 24VAC on the blue
and white damper cable wires (orange and black damper motor circuit board wires) whenever there is a command
output for the damper to open, and constant nominal 24VAC on the red and white damper cable wires (brown and
black damper motor circuit board wires). The damper will not close if nominal 24VAC is not present on these wires.
Note: There are no user-serviceable parts inside the IVRC; modi cation or attempted  eld service will void the
warranty.

Damper fails to close: Remove the cap from the damper motor and make sure the small slide switch on the
circuit board is switched
for the speci c damper is
to white cable wire (black circuit board wire). If nominal 24V is present and the damper will not close, check
for voltage from blue cable wire (orange circuit board wire) to white cable wire (black circuit board wire).
If nominal 24V is NOT present on orange and black wires, replace the damper motor assembly. If the
orange and black wires have voltage and the corresponding IVRC indicator is not illuminated, check the
IVRC for correct operation.

away from the round base (see FIG 9 below). Next, while the IVRC indicator lamp

NOT illuminated, check for voltage from red cable wire (brown circuit board wire)

FIG 9

•

•

Venstar Thermostat and Outdoor Air Sensor:

Please refer to thermostat and outdoor air sensor instructions for details on troubleshooting and operation.

When properly con gured, the thermostat should energize its Y1 & G terminals when free cooling conditions exist.
The following conditions must be met for Ventilation (“Free”) Cooling to occur:

• Outdoor temperature sensor must be properly installed, thermostat must be con gured for sensor to be

• Sensed outdoor temperature (as indicated on the thermostat) must be at or below the setting for “Useable

• Sensed outdoor temperature (as indicated on the thermostat) must be

No indicator lamps illuminated on IVRC: Check for nominal 24VAC on the CX and RX terminals (1 & 2) on
the IVRC. If there is voltage present and no damper output indicators are illuminated, the IVRC must be
replaced. If there is no voltage on CX and RX, check the
transformer has power, check for 24VAC output from the transformer.

No change in IVRC outputs and/or indicator illuminations when Ventilation Cooling should be activated by
the thermostat: check for nominal 24VAC from the thermostat from Y1 to C on the IVRC. If voltage is
present but the system does not activate, the IVRC must be replaced. If no voltage is present, check the
thermostat for voltage output on Y1.

for outdoor temp sensing

Outdoor Temp”. The outdoor temp sensor may be calibrated as explained in the thermostat instructions, if
desired.

below the indoor temperature setpoint.

ventCool™ 24VAC transformer for input power. If the

at least three or more degrees F

• Indoor sensed temperature must be

depending on o set or deadband settings.

at least two degrees F above the indoor temperature setpoint,

page 14

NOTE

NOTE: The thermostat will not activate Automatic Ventilation Cooling when outdoor temperatures are above

Speci cations

IVRC Damper Control Module:

Wiring Requirements:

Operating Voltage:

Maximum Operating Power:

Operating Ambient Temperature Range:

Operating Humidity Range:

Shipping Temperature Range:

Ventilation Cooling Air Dampers:

Minimum Wiring Requirements:

Maximum Voltage: 32 VAC

Motor Performance:

Motor Rating:

Operating Ambient Temperature Range:

Operating Humidity Range:

Shipping Temperature Range:

Venstar® T7850 Thermostat:

Venstar® ACC-TSEN Outdoor Temperature Sensor:

Trio™ Media Air Cleaner: TrioMAC8-2025 - Trio Mac 20x25 Merv 8

the “Useable Outdoor Temperature” setting. Also, if a cooling call was present while the outdoor temperature
was above the “Useable Outdoor Temperature” setting, mechanical air conditioning will not transition into
Ventilation (“Free”) Cooling until outdoor temperatures dropdown below the setpoint, until the indoor
temperature setting is reached by means of mechanical cooling, and the thermostat is satis ed
(mechanical cooling shuts o ). Ventilation cooling will occur with the next cooling call if the outdoor temp remains
below the “Useable Outdoor Temperature” setting.

Speci cations

IVRC Damper Control Module:

Wiring Requirements: 18 – 22 AWG, 24 VAC min.

Operating Voltage: 18-32 VAC

Maximum Operating Power: 40VA

Operating Ambient Temperature Range: -40°F to 185°F (-40°C to 85°C)

Operating Humidity Range: 5 to 90 % RH (non-condensing)

Shipping Temperature Range: 14°F to 140°F (-10°C to 60°C)

Ventilation Cooling Air Dampers:

Minimum Wiring Requirements: 24 VAC 22 AWG

Maximum Voltage: 32 VAC

Motor Performance: 2 RPM @ 60Hz, CW Rotation viewing shaft

Motor Rating: Insulation Class A (105C) Permanent magnet synchronous, 4W Input power

Operating Ambient Temperature Range: 32°F to 175°F (0°C to 80°C)

Operating Humidity Range: 5 to 90 % RH (non-condensing)

Shipping Temperature Range: -20 °F to 180°F (-29°C to 82°C)

Venstar® T7850 Thermostat:

Refer to manufacturer’s speci cation in installation manual. Installation manual can be downloaded at
www.venstar.com

Venstar® ACC-TSEN Outdoor Temperature Sensor:

10K ohm at 77F/25C, negative Temperature Coe cient. Refer to manufacturers speci cations for additional
information.

Trio™ Media Air Cleaner: TrioMAC8-2025 - Trio Mac 20x25 Merv 8

page 15

WARRANTY

WARRANTY

For warranty information about this or any Field Controls product, visit

www. eldcontrols.com

Phone: [phone] • Fax: [phone]

www.fieldcontrols.com

© Field Controls, LLC P/N 46696100, Rev B 03/16