If this furnace is used during construction when adhesives,
sealers, and/or new carpets are being installed, make sure all
combustion and circulating air requirements are followed. If
operation of the furnace is required during construction, use
clean outside air for combustion and ventilation. Compounds
of chlorine and fluorine when burned with combustion air
form acids which will cause corrosion of the heat exchangers.
Some of these compounds are found in paneling and dry wall
adhesives, paints, thinners, masonry cleaning materials, and
many other solvents commonly used in the construction
process.
NOTE:
Excessive exposure to contaminated combustion-air will
result in safety and performance related problems.
For accessory installation details, refer to the applicable installa-
tion literature.
NOTE:
Remove all shipping brackets and materials before oper-
ating the furnace.
This furnace is equipped with a metal blower wheel shipping
bracket which MUST be removed before starting the unit.
Table 1—Attic or Alcove Clearances From
Combustible Materials (In.)
UNIT SIZE
050, 075, 100,
AND 125
Sides
0
Back
0*
Top of Plenum
0
Vent Connector
(PVC Pipe)
0
Front Casing
1†
Front Service
30
* Zero in. with controls on front of furnace, 1 in. from back of elbow with
combustion-air inlet on back of furnace, and 1 in. from end of inducer motor
with controls located on back of furnace.
† Measured from end of inducer motor.
Table 2—Dimensions (In.)
UNIT SIZE
LENGTH
WIDTH
WEIGHT (LB)
050-12
55
13-1/2
136
075-12
55
13-1/2
148
100-16
55
17
167
125-20
55
20-1/2
185
INSTALLATION
Step 1—Location
This furnace may be located in an attic, basement, crawlspace,
alcove, or suspended from the ceiling of a utility room or
basement.
Fig. 1—Dimensional Drawing
Dimension (In.)
INPUT BTUH
UNIT WIDTH
DUCT SUPPLY
AND RETURN
OPENINGS
COMBUSTION-AIR
VENT DIAMETER
NUMBER OF
HEAT EXCHANGERS
A
B
C
D
50,000
13-1/2
11-5/8
2
2
75,000
13-1/2
11-5/8
2
3
100,000
17
15-1/8
3*
4
125,000
20-1/2
18-5/8
3*
5
* Vent size is 3 in. with factory-supplied 2-X-3 in. bell reducer.
A91190
5
⁄
8
″
5
⁄
8
″
5
⁄
8
″
3
″
1
7
⁄
8
″
27
1
⁄
2
″
14
1
⁄
2
″
6
3
⁄
8
″
7
⁄
8
″
7
″
21
3
⁄
8
″
23
1
⁄
8
″
7
⁄
8
″
17
″
26
1
⁄
4
″
31
3
⁄
4
″
55
″
4
1
⁄
4
″
3
1
⁄
8
″
4
1
⁄
2
″
3
1
⁄
2
″
2
7
⁄
8
″
A
B
B
A
1
⁄
2
″
GAS CONNECTION
C (VENT CONNECTION)
7
⁄
8
″
ELECTRICAL
CONNECTION
ELECTRICAL &
THERMOSTAT
CONNECTION
D (NUMBER OF HX)
COMBUSTION-AIR
CONNECTION
1
⁄
2
″
CONDENSATE DRAIN
AIR FLOW
2
