Bard CRVS-5A Commercial Room Ventilator with Exhaust Instruction Manual
- June 13, 2024
- Bard
Table of Contents
Bard CRVS-5A Commercial Room Ventilator with Exhaust
Product Information
- Model : CRVS-5A
- Manufacturer : Bard Manufacturing Company, Inc.
- Location : Bryan, Ohio 43506
- Website : www.bardhvac.com
- Manual : 2100-760A (Supersedes: 2100-760)
- Date : 11-14-22
- Page : 1 of 17
Installation Instructions
General Information
The ventilator should only be installed by a trained heating and air
conditioning technician. These instructions serve as a guide to the technician
installing the ventilator package. They are not intended as a step-by-step
procedure with which the mechanically inclined owner can install the package.
Unpacking
Upon receipt of the equipment, be sure to compare the model number found on
the shipping label with the accessory identification information on the
ordering and shipping document to verify that the correct accessory has been
shipped. Inspect the carton housing of each ventilator as it is received.
Before signing the freight bill, verify that all items have been received and
that there is no visible damage. Note any shortages or damage on all copies of
the freight bill. The receiving party must contact the last carrier
immediately, preferably in writing, requesting inspection by the carrier’s
agent. Concealed damage not discovered until after loading must be reported to
the carrier within 15 days of its receipt.
Description
The CRVS-5A ventilator is designed to be used with Bard heat pump models
T36-60H and T36-60S. It is an electromechanical vent system designed to
provide fresh air to meet indoor air quality standards.
Models
When installed in the above-listed models, the CRV provides built-in
exhaust provisions. When the damper blade opens to bring fresh air in, the
damper also opens an exhaust relief. The exhaust air will flow into the
condenser section of the unit. The condenser fan will help draw exhaust air
out.
CRV Features
- One-piece construction—easy to install with no mechanical linkage adjustment required.
- Exhaust air damper—built-in with positive closed position. Provides exhaust air capability to prevent pressurization of tight buildings.
- Actuator motor—24 volt, power open, spring return with built-in torque limiting switch.
- Provides up to 75% of outside air.
WARNING: Electrical shock hazard.
Disconnect the remote electrical power supply or supplies before servicing. Failure to do so could result in electric shock or death.
WARNING: Exposed moving parts.
Disconnect all electrical power before servicing. Failure to do so can result in severe injury or amputation.
CAUTION: Sharp metallic edges.
Take care and wear appropriate protective devices to avoid accidental contact with sharp edges. Failure to do so can result in personal injury.
Sequence of Operation
On a call for blower operation, the CRV will open to pre-purge position as set by the “OCC” potentiometer. A call for 1st stage cooling or heating cycles the compressor, and the dampers reposition to the Y1potentiometer setpoint. A call for 2nd stage cooling or heating energizes the compressor solenoid and repositions the damper blade to the Y1 potentiometer position. On loss of blower operation, the CRV closes fully.
INSTALLATION
Basic Installation
- Unpack the ventilator assembly which includes the integral ventilator with attached electrical harness and miscellaneous hardware.
- WARNING: Open and lock the disconnect switch before installing this accessory to prevent injury or death due to electrical shock or contact with moving parts. Turn the thermostat off.
- Remove and save the existing exterior blower access, filter access, and service access panels on the Bard wall mount unit (see Figure 1).
- Remove and save the existing unit air filter and screws from the front center grille (see Figure 2).
- Remove the front CRV exhaust cover plate.
- For Installation of Left Hand Units Only Remove strain relief on the right side of CRVS (see Figure 3). Unclip the two (2) wire ties holding the wire harness. Reroute wires to the left side of CRVS. Re-install wire ties in left side holes. Route wires through the left side and re-install strain relief.
- Insert the ventilator into the unit to the far left side clearing the right filter bracket (see Figure 4). Once the ventilator is fully inserted, slide the ventilator to the right until it is tight against the back of the control panel.
- IMPORTANT: Position the front lip of the ventilator on top of the front grille and condenser partition (see Figure 2 inset). This is important to ensure proper drainage of any water entering the damper assembly.
- Open the control panel to gain access to the unit’s low-voltage terminal block.
- Route electrical harness leads through the 7/8″ bushing in the control panel into low voltage box as shown in Figure 4.
- Connect leads with fork terminals to corresponding points on the unit terminal strip. (See manual 2100- 507 for air conditioner connection diagrams or manual 2100-516 for heat pump connection diagrams.)
- Close the control panel cover.
- Replace the left filter support, filter, and four (4) screws in the condenser grille.
- Re-install the blower access panel at the top of the unit and secure it with sheet metal screws.
- Ventilator Checkout
- A. Resupply power to the unit.
- B. Move the “PP” jumper on the CRV control board (Bard P/N 8201-167) to the 30-minute position.
- C. The ventilator should open to the position set by the “PP” potentiometer. Cycle the potentiometer from fully open to fully closed. Observe damper blade operation throughout travel to ensure free, unobstructed movement. Return the “PP” potentiometer to the desired position for pre-purge airflow (refer to graphs 1 and 2 on pages xx-xx). Move the “PP” jumper to the 0 position. The ventilator should open to the position set by the “OCC” potentiometer. Energize Y; the ventilator should open to the position set by the “Y1” potentiometer. Energize Y1; the ventilator should open to the position set by the “Y2” potentiometer.
- D. De-energize evaporator blower. The damper blade should close.
- E. If the pre-purge function is desired, move the “PP” jumper to the 30-, 60-, or 90-minute position depending on the desired pre-purge time.
- F. This completes ventilator checkout.
- Adjust the damper blade for required ventilation airflow in blower only, stage 1, and stage 2 cooling/heating mode (see Blade Adjustment for Desired Ventilation Air).
- Replace the mist eliminator. Be sure it is installed with the drain holes to the bottom.
- Remove the blank off plate or barometric fresh air damper installed on the service access door. Plug four (4) mounting holes with the plastic plugs provided with the ventilator.
- Replace the service access panel.
- A ventilator is now ready for operation.
Blade Adjustment for Desired Ventilator Air
The amount of ventilation air supplied by the commercial room ventilator is
dependent on four (4) factors:
- Return air duct static pressure drop.
- Supply air duct static pressure drop.
- Indoor blower motor speed.
- Damper blade open position setting.
Refer to the graph below to determine the blade setting necessary to achieve the ventilation air required for each operating mode.
Factory default settings are:
| PP Potentiometer | Closed | Closed |
|---|---|---|
| OCC Potentiometer | B | B |
| Y1 Potentiometer | B | B |
| Y2 Potentiometer | B | B |
The vent is factory-set to supply between 100 and 200 CFM of fresh air in all modes of occupied operation. For more accurate adjustment, use a flow hood over the intake opening to measure and adjust the airflow operation.
- PP Potentiometer: Adjusts the airflow during pre-purge mode (If the jumper is installed in positions 30-90)
- OCC Potentiometer: Adjusts the airflow during blower-only operation, or an occupied input from an applicable thermostat.
- Y1 Potentiometer: Adjusts the airflow during 1st stage cooling or heating operation
- Y2 Potentiometer: Adjusts the airflow during 2nd stage cooling or heating operation
- Energize the blower-only mode and adjust the OCC potentiometer to the desired airflow.
- Energize 1st stage cooling mode and adjust the Y1 potentiometer to the desired airflow.
- Energize 2nd stage cooling mode and adjust the Y2 potentiometer to the desired airflow.
If pre-purge mode is desired, de-energize cooling modes. Move the PP jumper to
the 30-, 60-, or 90-minute position and adjust the PP potentiometer to the
desired airflow. The minimum damper position when using a CO2 control damper
should be fully closed at 700 ppm or lower, if not potentiometer OCC can be
adjusted counter-clockwise (CCW) to close it. If it is fully closed at 700 ppm
or lower, no adjustments are required.
CO2 Control
For CO2-based control, add a CO2 sensor/controller (Bard P/N 8403-096) to
the wall and run additional optional wires as shown in Figure 5 on page 9. The
CO2 controller also must be re-configured from the standard default settings
as it comes out of the box. See Figure 4 on page 8 for complete details.
“V” Option CRV Sequence of Operation
The “V” Ventilation option includes a control board with blade positioning
potentiometers along with an input for a 2-10V input signal (see Figure 6).
Adjustable potentiometers:
- “PP” Potentiometer setting: This potentiometer can be used to adjust the blade setting for outdoor air intake during a pre-purge cycle. The pre-purge cycle time is based on the setting of the pre-purge timer.
- “ OCC” Potentiometer setting: This potentiometer can be used to adjust the blade setting for outdoor air intake when the “01” terminal is energized on the low voltage terminal strip indicating occupancy.
- “Y1” Potentiometer setting: This potentiometer can be used to adjust the blade setting for outdoor air intake when the “Y” terminal is energized on the low voltage terminal strip indicating 1st stage cooling or Balanced Climate operation. When energized, it overrides the “OCC” potentiometer setting.
- “Y2” Potentiometer setting: This potentiometer can be used to adjust the blade setting for outdoor air intake when the “Y1” terminal is energized on the low voltage terminal strip indicating 2nd stage cooling operation. When energized, it overrides the “OCC” and “Y1” potentiometer settings.
Pre-Purge Feature
Pre-purge is used to ventilate a specified CFM amount before occupants enter
the room or structure. The control board has a built-in pre-purge timer that
can be set to 30-, 60- and 90-minute intervals by moving the jumper. This
timer will start when the jumper is installed and the “01” terminal is
energized on the low-voltage terminal strip. Blade adjustment can be made on
the PP potentiometer. Once the timer has timed out, the board will default to
the occupied setting and this blade position can be adjusted on the OCC
potentiometer. If the timer is set to 0 (off—shipped position), the occupied
setting is instantaneous and the pre-purge setting (PP) is no longer in the
sequence.
Occupied Setting
Occupied is used to ventilate a specified CFM amount when occupants enter
the room or structure. The control board will energize the occupied setting
after the pre-purge cycle, or if the pre-purge is disabled immediately when
the “01” terminal is energized on the low voltage strip. Blade adjustment can
be made on the OCC potentiometer.
Y1 Setting
Y1 is used to ventilate a specified CFM amount when Y cooling is energized.
The control board will energize the Y1 setting when Y is energized on the low-
voltage strip. Blade adjustment can be made on the Y1 potentiometer. This
potentiometer setting overrides the OCC-occupied setting.
Y2 Setting
Y2 is used to ventilate a specified CFM amount when Y1 cooling is energized.
The control board will energize the Y2 setting when Y1 is energized on the
low-voltage strip. Blade adjustment can be made on the Y2 potentiometer. This
potentiometer setting overrides the OCC occupied and the Y1 setting.
2-10V Operation
A CO2 sensor or other device sending a 2-10V signal can be used to control the
damper motor. Two control methods are available to control the damper motor:
- Method 1: The control board will accept a 2- 10VDC signal with a resistive load greater than 5000 ohms. Bard CO2 sensor 8403-096 can be used when the 2-10V output is connected to the blade connector on the unlanded gray wire from the CRV, located near the unit low voltage terminal strip. The occupied OCC potentiometer setting must be set to the off position for total modulation. The OCC potentiometer can be used to maintain a minimum blade position when “01” is energized.
- Method 2: The damper motor will accept a 2- 10VDC signal with a resistive load of less than 5000 ohms. This method involves bypassing the control board and powering the motor directly from the device providing the 2-10VDC modulating signal. The gray wire connected to the CO2 VIN on the control board must be spliced with the white wire running to the damper motor (OUT on the control board). The other end of the gray wire should be connected to the CO2 sensor as stated in Method 1.
During 2-10VDC operation with “01” energized and pre-purge timed operation active, DC voltage signaling occupancy from a source such as a CO2 sensor will increase ventilation amounts as needed.
GRAPH 1: Commercial Room Ventilator Performance Data: T36 with CRVS-5A
Blade Position
Vent Air, Cooling/Heating Mode Total Air, Cooling/Heating Mode
GRAPH 2: Commercial Room Ventilator Performance Data: T42 with CRVS-5A
Blade Position
Vent Air, Cooling/Heating Mode Total Air, Cooling/Heating Mode
GRAPH 3: Commercial Room Ventilator Performance Data: T48 with CRVS-5A
GRAPH 4: Commercial Room Ventilator Performance Data: T60 with CRVS-5A
Bard Manufacturing Company, Inc. Bryan, Ohio 43506 www.bardhvac.com
- Manual : 2100-760A
- Supersedes: 2100-760
- Date: 11-14-22