Additive Base Floor Opening Size; Installation On Cooling Coil Cabinet; Return Air Opening - Lennox G71MPP-36B-070 Installation Instructions Manual

Installation on Combustible Flooring
(Using an Additive Base)
1 - When unit is installed on a combustible floor, an addi-
tive base must be installed between the furnace and
the floor, The base must be ordered separately. See
table 2 for opening size to cut in floor.
Ak CAUTION
TABLE 2
ADDITIVE BASE FLOOR OPENING SIZE
Cabinet
Width
B Cabinet
(17.5")
C Cabinet
(21")
D Cabinet
(24.5")
Catalog
Number
11M60
11M61
11M62
Frontto Rear
in. mm
22 559
22 559
22 559
Side to Side
in. mm
18 - 3/4 476
22 - 3/4 578
25 - 3/4 654
G71MPP UNIT_ __T
SUPPLY AIR PLENUM
PROPERLY
R ,VE BASE
FIGURE 10
2 - After opening is cut, set additive base into opening.
3 - Check fiberglass strips on additive base to make sure
they are properly glued and positioned,
4 - Lower supply air plenum into additive base until ple-
num flanges seal against fiberglass strips.
NOTE - Be careful not to damage fiberglass strips,
Check for a tight seal.
5 - Set the furnace over the plenum,
6 - Ensure that the seal between the furnace and plenum
is adequate.
Installation on Cooling Coil Cabinet
1 - Refer to reverse-flow coil installation instructions for
correctly sized opening in floor and installation of cabi-
net,
2 - When cooling cabinet is in place, set and secure the
furnace according to the instructions that are provided
with the cooling coil, Secure the furnace to the cabinet,
3 - Seal the cabinet and check for air leaks,
Return Air Opening -- Downflow Units
Return air may be brought in only through the top opening
of a furnace installed in the downflow position.The follow-
ing steps should be taken when installing plenum:
1 - Bottom edge of plenum should be flanged with a
hemmed edge (See figure 11 or 12).
2 - Sealing strips should be used to ensure an airtight seal
between the cabinet and the plenum.
3 - In all cases, plenum should be secured to top of fur-
nace using sheet metal screws,
4 - Make certain that an adequate seal is made,
PLENUM --*.._ I"'t'_ "_
(Field Provided) _ SECURE FROM
• _L_UTSIDE CABINET
/ v II
J CABINET
SEALING STRIP _
II./
SIDE PANEL
(Field Provided) ...... II
Side View
II
FIGURE 11
PLENUM
(Field Provided_-._
SECURE FROM
INSIDE CABINET
Side View
SEALING STRIP
,_/.J.Field Provided)
/ CABINET
, SIDE PANEL
FIGURE 12
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