Bryant 355MAV instruction manual ShortVent 5 to 8 ft System, Combustion-Airand Vent Pipe Diameter

CAUTION: 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. Excessive exposure to contaminated combustion air will result in safety and performance related problems

WARNING: 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. Failure to follow this warning could result in fire, property damage, personal injury, or death.

WARNING: All combustion-air and vent pipes must be airtight and watertight. Pipes must also terminate exactly as shown in Fig. 39, 40, 41, 42, or 43. Failure to follow this warning could result in property damage, personal injury, or death.

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, and a 12-in. minimum offset pipe section is recommended, as shown in Fig. 37, to reduce excessive droplets from exiting vent pipe outlet.

VENT PIPE

	12″ MIN
12″ MIN	(305mm)
(305mm)
	VENT PIPE
COMBUSTION-AIR PIPE	COMBUSTION-AIR PIPE

HORIZONTAL TO ROOF	HORIZONTAL TO SIDEWALL
	COMBUSTION-AIR PIPE
	VENT PIPE
COMBUSTION-AIR PIPE
	12″ MIN
	(304.8mm)
12″ MIN	VENT PIPE
(304.8mm)
VERTICAL TO ROOF	VERTICAL TO SIDEWALL

NOTE: A 12-in. (304.8mm) minimum offset pipe section is recommended with short (5 to 8 ft / 1.5 to 2.5M) vent systems. This recommendation is to reduce excessive condensate droplets.

A96230

Fig. 37—Short Vent (5 to 8 ft) System

COMBUSTION-AIR AND VENT PIPE DIAMETER

Determine combustion-air and vent pipe diameter.

1.Using Table 7, individually determine the smallest combustion-air and vent pipe diameters allowed 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.

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