Installation manual

035-19599-001 Rev. A (1103)
6 Unitary Products Group
Horizontal Installations Without a Cooling Coil Cabinet
When installing this appliance, the furnace must be installed so as to
create a closed duct system, the supply duct system must be con-
nected to the furnace outlet and the supply duct system must terminate
outside the space containing the furnace. When replacing an existing
furnace, if the existing plenum is not the same size as the new furnace
then the existing plenum must be removed and a new plenum installed
that is the proper size for the new furnace.
Attach the supply plenum to the furnace outlet duct flanges through the
use of S cleat material when a metal plenum is used. The use of an
approved flexible duct connector is recommended on all installations.
This connection should be sealed to prevent air leakage. The sheet
metal should be crosshatched to eliminate any popping of the sheet
metal when the indoor fan is energized. On all installations without a
coil, a removable access panel is recommended in the outlet duct such
that smoke or reflected light would be observable inside the casing to
indicate the presence of leaks in the heat exchanger. This access cover
shall be attached in such a manner as to prevent leaks.
RESIDENTIAL AND NON HUD MODULAR HOME
DOWNFLOW AND HORIZONTAL RETURN PLENUM
CONNECTION
The return duct system must be connected to the furnace inlet and the
return duct system must terminate outside the space containing the fur-
nace. When replacing an existing furnace, if the existing plenum is not
the same size as the new furnace then the existing plenum must be
removed and a new plenum installed that is the proper size for the new
furnace.
Attach the return plenum to the furnace inlet duct flanges. This is typi-
cally through the use of S cleat material when a metal plenum is used.
The use of an approved flexible duct connector is recommended on all
installations. The connection of the plenum to the furnace and all the
ducts connecting to the plenum must be sealed to prevent air leakage.
The sheet metal should be crosshatched to eliminate any popping of
the sheet metal when the indoor fan is energized.
The duct system is a very important part of the installation. If the duct
system is improperly sized the furnace will not operate properly. The
ducts attached to the furnace must be of sufficient size so that the fur-
nace operates at the specified external static pressure and within the air
temperature rise specified on the nameplate.
Attic installations must meet all minimum clearances to combustibles
and have floor support with required service accessibility.
IMPORTANT: if an external mounted filter rack is being used see the
instructions provided with that accessory for proper hole cut size.
SECTION III: FILTERS
DOWNFLOW APPLICATION
All applications require the use of a filter. All Downflow models must
have a field-supplied external rack and filters that has the dimensions
shown below.
FIGURE 2: Dimensions
B
45
A
3/4
20
5-1/4
1-1/4
3-1/4
2-3/4
28-1/2
6-1/4
18-1/2
1-3/4
4-1/8
7/1/2
16-3/4
3-3/4
5-1/4
1-1/4
B
20
1-7/8
D
2-1/2
5-3/8
8
A
1-3/8
9-1/4
C
TOP IMAGE
SUPPLY END
BOTTOM IMAGE
RETURN END
BTUH (kW)
Input/Output)
CFM
(m
3
/min)
Cabinet
Size
CABINET DIMENSION
A A (cm) B B (cm) C C (cm) D D (cm)
40/37 (11.71/10.84) 1000 (28.32) A 14-1/2 36.8 13-1/4 33.6 12 30.4 5-3/4 14.6
60/55 (17.57/16.10) 1200 (33.98) B 17-1/2 44.4 16-1/4 41.3 15-1/8 38.4 6-3/4 17.1
80/75 (23.42/21.96) 1200 (33.98) B 17-1/2 44.4 16-1/4 41.3 15-1/8 38.4 6-3/4 17.1
80/75 (23.42/21.96) 1600 (45.31) C 21 53.3 19-3/4 50.2 18-1/2 47.0 8-1/2 21.6
100/95 (29.28/27.82) 2000 (56.63) C 21 53.3 19-3/4 50.2 18-1/2 47.0 8-1/2 21.6
120/112 (35.14/32.80) 2000 (56.63) D 24-1/2 62.2 23-3/8 59.4 21-7/8 55.6 10-1/4 26.0
T’STAT WIRING
LEFT SIDE
FRONT
RIGHT SIDE
FRONT
FRONT
7/8 K.O.
CONDENSATE
DRAIN ACCESS
3-1/4 X 3
AIR INTAKE
3-5/8 X 3-5/8
CONDENSATE
DRAIN ACCESS
3-1/4 X 3
GAS INLET
1-1/4 X 2-1/2
AIR INTAKE
3-5/8 X 3-5/8
ALT. GAS INLET
1-1/4 X 2-1/2
POWER
WIRING
7/8 K.O.
VENT CONNECTION
ALL DIMENSIONS ARE IN INCHES, AND ARE APPROXIMATE