12
I-EEDU (02-21) 150492-A
INSTALLATION—CONTINUED
Pre-Installation Modifications—Continued
High CFM Conversion—Continued
Figure 5. Field Conversion Label
Reverse Airflow Conversion
Duct furnaces are equipped with directional air baffles between the heat exchanger tubes . Facing the control
compartment of the furnace, the standard direction of airflow is from the rear of the furnace (gas valve location)
toward the front of the furnace . If the installation site requires airflow from the front to the rear, the unit may be field-
adapted by relocating the limit control and reversing the position of the directional air baffles as follows:
NOTE: When reversing airflow, the limit control MUST be relocated to the discharge end of the
heat exchanger.
1. Remove limit control (see
, DETAIL A):
a . If unit has optional outer side panels, locate limit control and remove outer side panel on that side of furnace .
b . Remove limit control bracket screws and remove limit control/bracket assembly . Do not disconnect limit control
wires .
c . Carefully pull limit control/bracket assembly through hole .
2. Reverse direction of airflow baffles (see
a . Remove baffle screws and lift each airflow baffle slightly and slide forward . Remove all baffles from heat
exchanger .
b . Remove top baffle support screws and remove top baffle support . Reposition and secure support on opposite
end of heat exchanger using screws .
c . Remove bracket screws and remove bottom baffle support and bracket assembly . Reinstall bracket screws
to plug holes in heat exchanger bottom . Reposition bottom baffle support and bracket assembly on opposite
end of heat exchanger and secure using field-supplied sheet metal screws .
d . Reinstall airflow baffles removed in step 2a and secure using baffle screws .
3. Reinstall limit control removed in step 1:
a . Measure down 4-1/2 inches (114 mm) and across 1-11/16 inches (43 mm) at discharge end on same side of
heat exchanger . Using that center point, punch 2-1/4-inch (57-mm) diameter hole in side panel .
b . With limit control on heat exchanger side of bracket, slide limit control/bracket assembly through hole and
secure bracket using two sheet metal screws .
NOTE: If cable connections need to be moved, after the limit control is installed, secure them using
field-supplied sheet metal screws. Reinstall screws to plug all holes in the side panel.
c . Cover all original factory-made limit control holes using field-supplied sheet metal plate . Do not leave any
open holes in side panel or heat exchanger bottom . Unit is now ready for installation with airflow from front to
rear (gas valve side) .
(date)
(name & address of company making this conversion)
263308
