7.1 W
HAT YOU
N
EED TO
B
ALANCE THE
U
NIT
•
A magnehelic gauge capable of measuring 0 to 0.5 inch of water (0 to 125 Pa) and
2 plastic tubes.
•
The balancing chart of the unit.
7.2 P
RELIMINARY
S
TAGES TO
B
ALANCE THE
U
NIT
•
Seal all the unit ductwork with tape. Close all windows and doors.
•
Turn off all exhaust devices such as range hood, dryer and bathroom fans.
•
Make sure the integrated balancing dampers are fully open.
•
Make sure all filters are clean (if it is not the first time the unit is balanced).
7.3 B
ALANCING
P
ROCEDURE
1.
Set the unit to high speed.
Make sure that the furnace/air handler blower is ON if the installation is in any way connected to the ductwork of the cold air return. If not,
leave furnace/air handler blower OFF. If the outside temperature is below 0°C / 32°F, make sure the unit is not running in defrost while
balancing. (By waiting 10 minutes after plugging the unit in, you are assured that the unit is not in a defrost cycle.)
2.
Place the magnehelic gauge on a level surface and adjust it to zero.
3.
Connect tubing from gauge to EXHAUST air flow pressure taps (see diagram beside).
Be sure to connect the tubes to their appropriate
high/low fittings. If the gauge drops below
zero, reverse the tubing connections.
NOTE: It is suggested to start with the exhaust air flow reading because the exhaust has
typically more restriction than the fresh air, especially in cases of fully ducted
installations or source point ventilation. Place the magnehelic gauge upright and
level. Record equivalent AIR FLOW of the reading according to the balancing chart.
4.
Move tubing to FRESH air flow pressure taps (see diagram). Adjust the fresh air balancing
damper until the FRESH air flow is approximately the same as the EXHAUST air flow. If
FRESH air flow is less than EXHAUST air flow, then go back and adjust the exhaust balancing
damper to equal the FRESH air flow.
5.
Secure both dampers in place with tape or with a fastening screw.
6.
Write the required air flow information on a label and stick it near the unit for future reference
(date, maximum speed air flows, your name, phone number and business address).
NOTES: 1. Use conversion chart provided with the unit to convert magnehelic gauge readings to equivalent cfm values.
2. The unit is considered balanced even if there is a difference of ±10 cfm (or ± 5 l/s or 17 m³/h) between the two air flows.
VP0010
Fresh air flow
Exhaust air flow
7. BALANCING THE UNIT
VD0051
VP0009
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