6
ERV/Furnace ducting for Partially Dedicated System
Air from inside
* Unit air flow should be balanced while ERV is on "Normal" speed and
furnace blower is running.
Air return
1 m (3' 3")
min.
recommended
Cold air
return
* Ductwork layout may
differ depending on model
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. Furnace blower must operate when ventilation from ERV is required. The
furnace should be set to run continuously or interlocked with ERV .
See
furnace electrical connection on page 19.
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"
Stale air to
outside
Fresh air from
outside
Fresh air to
living areas
Fantech energy recovery ventilators (ERV) that use a supply fan shutdown for frost preven-
tion do not include an outdoor air motorized damper. If you are using a simplified instal-
lation, 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
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
Summary of Contents for FIT 120E
Page 18: ...18 Wiring diagram Observe polarity on all accessory controls where applicable ...
Page 46: ...46 Note ...
Page 47: ...47 Note ...
