Inspir
AIR™ Home Standard Residential HRV/ERV
10
5. Backdraft or motorized dampers may be built into the HRV/ERV to prevent entry of
outdoor air during off cycles, but they should not be installed in the duct leading to the
outside.
Due to these reasons, it may be preferable to avoid a direct duct connection to the return of
the AHU and use an
indirect approach
instead.
Indirect Configuration
In this configuration, dedicated exhaust grilles remove stale air from bathrooms, laundry
rooms, and kitchens. Fresh air is supplied to a large-volume room, such as a great room,
family room, high stairway, etc. The forced-air system will draw the fresh air into the return
grilles of the AHU and distribute it throughout the house. The HRV/ERV and AHU may operate
independently with no impact on airflow balance. A thermostat with a ventilation feature
is recommended to turn on the AHU periodically to assure proper supply air distribution
apart from heating/cooling cycles. This type of timer avoids the energy cost of operating
the blower fan in the AHU, and it also lessens the concerns about draft in winter and re-
evaporation from the AC coil in the summer.
HVAC AHU
HVAC RETURN DUCT
HVAC SUPPLY DUCT
*Note: Port configurations
are generic and do not
represent specific models
HRV/ERV supply in
living/family rooms with
return grilles for HVAC
INDOOR AIR
SUPPLY AIR
OUTDOOR AIR
EXHAUST AIR
6 ft min
Bath 1
Bath 2
Kitchen
Laundry
