18-CD35D1-1 11
INSTALLER’S GUIDE
FILTER
REMOVE FILTER FROM UPFLOW
FURNACE WHEN RETURN DUCT IS
ATTACHED TO FURNACE TOP SIDE
(HORIZONTAL APPLICATIONS) AS
SHOWN.
Close coupled (less than 36")
return (filter directly beneath bottom
side return) not recommended due to
noise considerations. If used, securely
attach 1/2" mesh metal hardware cloth
protective screen to the inside bottom of
filter grill.
0
*SEE OUTLINE DRAWING
q
LOCATING
NOTCHES
PROVIDED
FOR SIDE
RETURN
CUTOUT
*
*
*
*
CUT OUT
FOR SIDE
FILTER
FRONT of
Furnace
TABLE 4
MINIMUM CLEARANCE FROM COMBUSTIBLE MATERIALS
FOR UPFLOW/HORIZONTAL LEFT AND DOWNFLOW/
HORIZONTAL RIGHT FURNACES
UNIT
LOCATION
FURNACE
SURFACE
VERTICAL
CLOSET
HORIZONTAL
CLOSET
HORIZONTAL
ALCOVE /
ATTIC
SIDES
0"
1"
0"
BACK
0"
3"
6"
TOP
1"
1"
1"
FRONT
3"
3"
18"
VENT
0"
0"
0"
NOTE: CLEARANCE REQUIRED AT TOP OF PLENUM IS 1"
RETURN AIR FILTERS
(Filter and filter rack are not supplied with unit)
TYPICAL DOWNFLOW FURNACE
RETURN AIR FILTER INSTALLATIONS
Two high velocity type air filters are required for each downflow
furnace. Downflow furnaces in the horizontal configuration must
have the filters outside of the cabinet.
Airflo
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Typical installations are shown in Figure 22 and 23. Table 8 and 9
provide information for installation of the filter retaining brackets
shipped with downflow furnaces.
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9. When replacing a furnace, old duct work should be
cleaned out. Thin cloths should be placed over the
registers and the furnace fan should be run for 10 minutes.
Don’t forget to remove the cloths before you start the
furnace.
w
Typical Filters of Upflow in Horizontal
Airflo
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BAYBRCKFLT10