9
RETURN AIR TEMPERATURE
This furnace is designed for continuous return--air minimum temperature of 60
_
F (15
_
C) db or intermittent operation down to 55
_
F (13
_
C)
db such as when used with a night setback thermometer. Return--air temperature must not exceed 80
_
F (27
_
C) db. Failure to follow these
return air limits may affect reliability of heat exchangers, motors and controls.
60
80
/ 27
˚
C
/ 16
˚
C
SUPPLY AIR
A10490
MINIMUM CLEARANCES TO COMBUSTIBLE MATERIALS
POSITION
CLEARANCE
Rear
0 (0 mm)
Front (Combustion air openings in furnace and in structure)
1 in. (25 mm)
Required for service
*24 in. (610 mm)
All Sides of Supply Plenum
1 in. (25 mm)
Sides
0 (0 mm)
Vent
0 (0 mm)
Top of Furnace
1 in. (25 mm)
* Recommended
COMBUSTION--AIR PIPE FOR NON--DIRECT (1--PIPE) VENT APPLICATION
FIELD-SUPPLIED
2-IN. (51 mm) DIA.
PVC PIPE
FIELD-SUPPLIED
2-IN. (51 mm) DIA.
TIGHT RADIUS
PVC 90
°
ELBOW
12” (300 mm) Minimum
A11487
