Rev 6.1 November 1, 2016
12
Manometer
Balancing Air Flows
Balanced air flow between the supply and exhaust air streams is essential to the performance of an HRV
or ERV. With the Windsor Series, changing motor speeds or balancing is quick and simple with two
buttons recessed slightly into the unit’s cabinet—see next section. NO BALANCING DAMPERS ARE
REQUIRED. Once the HRV system is installed and the vapour barrier is completed, ensure the
following:
▪
Close all windows, doors and fireplace dampers
▪
Turn off any exhaust systems such as dryers, range hoods, bath fans and central vacuums.
▪
With multiple-speed forced air furnaces in Extended or Simplified systems, the furnace should
operate at continuous low speed.
▪
During balancing, activate high speed on the HRV/ERV by remote control or by temporarily
installing a jumper wire between R and Hi on the unit’s 10-wire, 24 VAC terminal block.
To balance the air flows, you will need a device to measure air flow. It is recommended to use either a
magnehelic gauge or differential pressure digital manometer capable of measuring 0 to 0.5 inch of water
(0-125 Pa). Depending on the device you are using, follow one of the two procedures below.
Magnehelic Gauge and Flow Grid:
1.
Disconnect the flex connector from the rigid duct before any branch ducts.
Compress the flex duct and insert the flow grid. Tape the joint between the flow grid
and ductwork.
2.
Mount the magnehelic gauge level and plumb. Join the hoses from the flow grid to
the magnehelic gauge. The needle of the magnehelic gauge should read positively.
Switch hose connections if the needle falls below zero.
3.
Record reading from gauge and adjust the motor speed to the desired CFM.
4.
Repeat the procedure for the next duct. Adjust motor speeds until air flow readings
are equal or within 10% of each other.
Differential Pressure Manometer or Magnehelic Gage and Units with Pressure Ports
NOTE: For 2-door units, the PRESSURE PORT locations might vary from those
illustrated here, depending on the orientation of the HRV/ERV.
Magnehelic Gage
