User Guide

7
2.2.3 SIMPLIFIED INSTALLATION (T-4 )
The central forced-air system must be synchronized with the unit since fresh air evacuation and distribution come from the
same section. The central forced-air system must operate to avoid fresh air to be directly drawn by the evacuation, which
would reduce signifi cantly fresh air supply to the building. See Section 3.3 for ducting.
CAUTION
Duct connection to the central forced-air system can be regulated by some codes and standards. It is your responsibility
to consider and comply with your local requirements to avoid any non-compliance.
WARNING
!
VH0168
Fresh air and exhaust air fl ow through the central forced-air system ducts,
which simplifi es the installation.
The use of bathroom fans and a range hood is suggested to exhaust stale
air.
STALE AIR EXHAUST DUCTWORK:
Connect the stale air intake port of the unit to the central forced-air
system return duct at least 3 feet ahead of the fresh air distribution from
the unit.
FRESH AIR DISTRIBUTION:
Connect the fresh air distribution duct of the unit to the central forced-
air system return duct at least 10 feet away from the central forced-air
system (A+B)*.
* This 10-ft. distance applies only in areas where the outside temperature
falls below the freezing point (32°F).
VH0167
C
B
A
A+B= MIN 10’
C=3’
ALTERNATE INSTALLATION (T-5):
Unit should be synchronized with central forced-air system operation
to avoid condensation and mold growth in central forced-air system
distribution ducting if cooling mode of central forced-air system is used.
Fresh air to
building
Stale air from
building
Stale air to
outdoors
Fresh air from
outdoors
This confi guration is not recommended with high velocity central
forced-air system. High pressures produced by these systems
could affect unit proper operation and generate errors.
CAUTION
NOTE: For this type of con guration, the T-5 option must be
selected on the LCD screen when auto-balancing the unit.
Stale air to
outdoors
Fresh air from
outdoors
Fresh air to
building
Stale air from
building
NOTE: For this type of con guration, the T-4 option must be
selected on the LCD screen when auto-balancing the unit.