Balancing Preparation
Prior to performing the air balancing procedure, perform the following steps:
Seal the ductwork.
Confirm the installation and proper operation of all the components of the HRV.
Fully open the balancing dampers.
Turn off all household exhaust devices (range hood, clothes dryer, bathroom fans).
Set the HRV at high speed.
Prior to balancing the unit, first adjust airflows in the branch lines to specific areas of the house.
If the outdoor temperature is below 0
o
C (32
o
F), ensure the unit is not running in defrost.
Place the magnehelic gauge on a level surface and adjust it to zero. If the system is a simplified
or partially dedicated installation, operate the furnace/air handler at high speed.
Balancing the Airflow With a Pitot Tube
Step 2:
Insert the pitot tube with the tip facing towards the air
stream in the stale air from building air stream. Move the pitot
tube around in the duct (facing toward the airflow) and take an
average reading. Record the reading.
Step 3:
Repeat Step 2 to measure the fresh air to
building duct.
Pitot tube tip facing
towards the air stream.
Magnehelic gauge must
be level.
Balancing
Damper
Drill 3/16 in holes in
stale & fresh air ducts.
Balancing Damper
Step 1:
Drill a 3/16 in hole in the duct, ideally 3 ft
downstream and 1 ft upstream of any elbows or
bends in the fresh air and stale air streams.
Fresh Air to Building
Stale Air from Building
Pitot tube tip facing
towards the air stream.
Magnehelic
gauge
must be level.
Step 4(a):
Review the readings and damper down the duct
with the highest duct velocity pressure. Repeat Step 2 and Step
3 until both ducts show identical readings.
Step 4(b):
Upon completion of balancing, seal the holes (foil
tape recommended).
Seal holes.
Balancing Damper
Balancing
Damper
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