Form 421, Page 14
15. Furnace Blower Connections
Requirements: Proper arrangements of blower and duct furnace with respect to
angle of approach of the duct connection and the arrangement of the discharge
opening of the blower are shown. Blowers should be bottom horizontal dis-
charge when coupled to the duct furnace. When a top horizontal discharge blower
is connected to the duct furnace, be sure that sufficient length of duct is pro-
vided to permit even flow of air at the end of the duct. Or, baffles may be in-
serted between the blower and the heater to assure an even flow of air across the
heat exchanger. See illustrations in Figure 14.

WARNING: The furnace must be installed on the

positive pressure side of the air-circulating blower. See

Hazard Levels, page 2.

Figure 14

4) Move to the left column to find out the required size of
the bypass duct.
Example: Bypass Duct
Size is 5"
Depth of the bypass duct is 18" on both inlet and outlet ends.
Bypass duct must be located on side opposite controls and 2"
from the heat exchanger side panel.
NOTE: Not all capacities are covered in this chart. If your
installation is not covered, the correct size may be determined
by consulting the factory representative.
14. Bypass Duct (cont'd)