CAUTION: UNIT CORROSION HAZARD
Excessive exposure to contaminated combustion air may result in safety and performance related problems.
Combustion air must not be taken from inside structure because inside air is frequently contaminated by halogens, which include
fluorides, chlorides, bromides, and iodides. These elements are found in aerosols, detergents, bleaches, cleaning solvents, salts, air
fresheners, adhesives, paint, and other household products. Locate combustion-air inlet as far as possible from swimming pool and
swimming pool pump house.
WARNING: FIRE AND EXPLOSION HAZARD
Failure to follow this warning could result in fire, property damage, personal injury, or death.
Solvent cements are combustible. Keep away from heat, sparks, and open flame. Use only in well-ventilated areas. Avoid breathing
in vapor or allowing contact with skin or eyes.
WARNING: CARBON MONOXIDE AND PROPERTY DAMAGE HAZARD
Failure to follow this warning could result in property damage, personal injury, or death.
All combustion-air and vent pipes must be airtight and watertight. Pipes must also terminate exactly as shown in Fig. 40, 41, 42, 43,
and 44.
NOTE:
The minimum combustion-air and vent pipe length (each) for these furnaces is 5 ft. Short pipe lengths (5-8 ft) may discharge water
droplets. These droplets may be undesirable; therefore, a 12-in. minimum offset pipe section is recommended to reduce excessive droplets from
exiting vent pipe outlet. (See Fig. 38.)
COMBUSTION-AIR AND VENT PIPE DIAMETER
Determine combustion-air and vent pipe diameter.
1. Using Table 9, individually determine the smallest combustion-air and vent pipe diameters permitted for each pipe. Pick the larger of these
2 pipe diameters and use this diameter for both combustion-air and vent pipes.
2. When installing vent systems of short pipe length, use the smallest allowable pipe diameter. Do not use pipe size greater than required or
incomplete combustion, flame disturbance, or flame sense lockout may occur.
Fig. 38—Short Vent (5 to 8 Ft) System for Direct Vent Applications
A96230
HORIZONTAL TO ROOF
HORIZONTAL TO SIDEWALL
VERTICAL TO SIDEWALL
VERTICAL TO ROOF
VENT PIPE
COMBUSTION-AIR PIPE
COMBUSTION-AIR PIPE
VENT PIPE
COMBUSTION-AIR PIPE
VENT PIPE
COMBUSTION-AIR PIPE
VENT PIPE
12
″
MIN
12
″
MIN
12
″
MIN
12
″
MIN
NOTE: A 12 In. minimum offset pipe section is recommended with
short (5 to 8 ft) vent systems. This recommendation is to reduce
excessive condensate droplets from exiting the vent pipe.
—36—
Summary of Contents for PG9MAA
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