W415-1066 / C / 06.22.12
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4.4 LOCATINg rETurN AIr FILTEr
the hmf100 can be installed with the return air
entering from the left, right, or rear of the furnace.
return air
return air
plenum
plenum
sTEp #4
• locate and level the hmf100.
• use levelling the legs to compensate for uneven floor and
snug lock nuts up to the furnace base to prevent movement
through vibration.
LEvEL LEg
LOCk NUT
refer to section 5.0 for Clearance to Combustibles materials / plenum and venting installation.
the furnace is shipped with an air filter and air filter frame. a rectangular hole must be cut into the chosen
panel to install the air filter frame. Choose the panel that you would like the return air plenum to enter and
perform the following four steps:
1. remove the four knockouts located in the panel.
2. mark a straight line between the outer edges of
all four holes, forming a rectangle.
LEFT RA
RIgHT RA
REAR RA
3. Cut along these four lines and remove the rect-
angle cut-out.
panel
knoCkouts
(X4)
