Broan VB0268 Manual De Instalación página 17

7. BALANCING THE UNIT
7.1 W N B
HAT YOU EED TO
• 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 B
EFORE YOU START
• 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 P
ALANCING 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
at right). 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 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).
7. Install 4 pressure taps plugs (included in parts bag).
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.
U
ALANCE THE NIT
VP0009
VP0022
17
VD0280
E
XHAUST AIR FLOW
F
RESH AIR FLOW