5.4 Installing Ductwork and Registers (cont’d)
5.4.2
Exhaust Ducted System (Source Point Ventilation) (see illustration, section 4.2)
Stale air exhaust ductwork:
(same as for Fully Ducted System, section 5.4.1)
Fresh air distribution:
There are two methods for connecting the unit to the furnace:
Method 1: supply side connection
• Cut an opening into the furnace supply duct at least 18” (0.5 m) from the furnace.
• Connect this opening to the fresh air distribution port of the HRV (use steel duct, see
Figure 11).
• Make sure that the HRV duct forms an elbow inside the furnace ductwork.
• If desired, interlock (synchronize) the furnace blower operation with the HRV operation.
(See section 6.2.)
5.0 Installation
(cont’d)
WARNING
!
When performing duct connection to the furnace, installation must be done in accordance with all applicable
codes and standards. Please refer to your local building code.
Method 2: return side connection
• Cut an opening into the furnace return duct not less than 10 feet (3.1 m) from
the furnace (A+B+C).
• Connect this opening to the fresh air distribution port of the HRV (see Figure 12).
NOTE: For Method 2, it is not essential that the furnace blower runs when the unit is
in operation, but we recommend it. If desired, interlock (synchronize) the
furnace blower operation with the HRV operation. (See section 6.2.)
CAUTION
When performing connection to the furnace supply duct, this duct must be sized to support the additional airflow
produced by the HRV. Also, use a steel duct. It is recommended that the HRV is running when the furnace is in
operation to prevent backdrafting inside the HRV.
16
VD0032
A
B
C
A+B+C= not less
than 10’ (3.1 m)
Figure 12
VD0173
minimum
18” (0.5 m)
Steel duct
Figure 11
