25
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 provided with the unit.
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 balancing dampers are fully open.
•
Make sure all filters are clean (if it is not the first time you balance the
unit).
B
ALANCING
P
ROCEDURE
1. Set the unit to high speed:
Make sure that the furnace blower is ON if the installation is in any way
connected to the ductwork of the cold air return. If not, leave furnace 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.)
Disconnect the wire of the bypass damper (Duo only).
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).
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).
Connect the wire of the bypass
damper (Duo only).
NOTE:
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.
10. Air Flow Balancing
VP0009
VP0010
VD0052
VE0021
VD0051
VP0011
SOLO
Fresh air flow
Exhaust air flow
Exhaust air flow
Fresh air flow
NOTE:
Always unplug bypass wire while
balancing a Duo.
DUO
