Troubleshooting guide

8
During the heating season, an HRV recovers heat from the
outgoing, stale household air and uses it to preheat incom-
ing, fresh outdoor air. The HRV then distributes the
incoming air throughout the house.
In the example shown in Figure 1, the flow of air in and out
of the house takes place simultaneously (note: the path of
the airflow may vary from one type of HRV to another).
The two air streams are always kept separate within the
HRV. Fresh outdoor air is filtered before it enters the HRV
core, where a circulation fan distributes the air throughout
the home via ductwork. A separate ductwork system draws
the stale indoor air back to the HRV, where
it is filtered and pushed by a fan through the heat exchange
core. Here, the stale air releases heat that is transferred
to the fresh air being drawn into the house.
During the air-conditioning season, the HRV reverses this
heat-exchange process, removing some of the heat from the
incoming air and transferring it to the outgoing air (see the
box on Energy Recovery Ventilators).
Energy Recovery Ventilators
Energy recovery ventilators, or ERVs, are a relatively new
type of HRV that can exchange both heat and moisture.
An ERV will give you more control over moisture levels
in your home, which can be an important consideration
depending on the local climate.
Where winter climates are extremely dry, ERVs can recover
some of the moisture that would be exhausted to the out-
doors by a regular HRV. This can help you maintain a com-
fortable humidity level within the home, avoiding static
electricity, sore throats and other discomforts caused by
air that is too dry.
During the air-conditioning season, on the other hand,
ERVs can help keep excess moisture out of the home by
extracting it from the incoming fresh air and transferring
it to the exhaust air. Since less energy is required to lower
the temperature of dry air compared to moist air, an ERV
can reduce the load on the air conditioner and save
you money.
00-211 english booklet 3/20/03 12:00 pm Page 8