TYPICAL MOUNTING POSITIONS
AIR FLOW
Figure 5
BASEMENT FURNACE (LOWBOY)
Filter is mounted horizontally in return plenum, just above furnace.
AIR FLOW
Figure 7
HIGHBOY FURNACE
Side installation. Filter is mounted vertically, where return air enters side inlet of furnace.
LESS THAN |
|
7 INCHES | OFFSET |
AT LEAST 9 INCHES
Figure 9
OFFSET INSTALLATION
Typical use of duct offset to match air fi lter opening.
If duct connection to furnace allows less than nine inches for mounting the air fi lter, shorten the lateral trunk, or attach an offset fi tting to the elbow.
AIR FLOW
Figure 6
COUNTERFLOW
FURNACE
Filter is mounted horizontally in return duct or plenum, just above furnace.
Figure 8
HIGHBOY FURNACE
Installation beneath furnace. Filter mounts horizontally, where return air enters from below. Raise furnace and install beneath base.
AIR FLOW
Figure 10
HORIZONTAL FURNACE
Filter is mounted vertically in the return duct near furnace.
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