6
fantech
ERV/ Furnace ducting for Partially Dedicated System
Stale air from inside
* Unit airflow should be balanced while ERV is on
“Normal” speed and furnace blower is running.
Outside
Fresh air
to living
areas
1 m (3' 3")
min.
recommended
Cold air
return
Stale air to
outside
Fresh air from
outside
INSTALLATION EXAMPLES
(CONT'D)
DIRECT CONNECTION of the FRESH air to living area to the RETURN PLENUM
of the AIR HANDLER (Stale air drawn from key areas of home)
PARTIALLY DEDICATED SYSTEM (BETTER)
1. In order to provide proper distribution of the fresh air, it is
recommended that the furnace blower be set to run continuously or
interconnected with ERV.
See furnace electrical connection on page
18.
2. Stale air is drawn from key areas of the home (bathroom, kitchen,
laundry room).
3. Fresh air is supplied to the return air plenum of the furnace.
4. Due to the difference in pressure between the ERV and the equipment
it is being connected to the ERV’s airflow must be balanced on site,
using the procedure found in the section “AIRFLOW BALANCING”
* In the case of a multi-zone system, please contact Fantech customer
service prior to installing any installation type requiring the use of the
furnace interlock"
Fantech energy recovery ventilators (ERV) that use a supply fan shutdown for frost
prevention do not include an outdoor air motorized damper. If you are using a simplified
installation, i.e. connecting the ERV supply air duct to a furnace's return air duct, the ERV
must operate continuously. When the ERV is turned off, no warm exhaust air will flow
through the ERV but the furnace's fan will continue to draw in outdoor air directly into the
furnace. If it's cold outside, cold air will be introduced, without re-heating, directly into
the furnace.
If the ERV is installed such that the homeowner may turn off the ERV during the winter, we
recommend installing a motorized damper between the ERV's supply air and the furnace's
return air duct that closes when the ERV is not operating. See wiring diagram (figure 1).
Damper
Motor
24 VAC Transformer
COM
NO
ERV Furnace interlock
See page 18.
24V
120V
Figure 1
*Transformer and Damper motor not included
Motorized Damper
Suggested installation for:
• Central furnace (air
handling unit or central
air conditioners)
• When ducting fresh
air to living area is not
possible or practical,
i.e. expensive or when
the central AHU will
operate year-round.
Benefits:
Conditions the
fresh air prior to
distributing it throughout
the house
