Air For Combustion And Ventilation - Payne PG9MAB Series A Installation Manual

Provisions for adequate combustion, ventilation, and dilution air must be provided in accordance with:
• U.S. Installations: Section 8.3 of the NFGC, Air for Combustion and Ventilation and applicable provisions of the local building codes.
• Canadian Installations: Part 7 of the NSCNGPIC, Venting Systems and Air Supply for Appliances and all authorities having jurisdiction.
WARNING: FURNACE CORROSION HAZARD
Air for combustion must not be contaminated by halogen compounds, which include fluoride, chloride, bromide, and iodide. These
elements may corrode heat exchangers and shorten furnace life. Air contaminants are found in aerosol sprays, detergents, bleaches,
cleaning solvents, salts, air fresheners, and other household products.
The following types of furnace installations may require OUTDOOR AIR for combustion due to chemical exposures:
• Commercial buildings
• Buildings with indoor pools
• Laundry rooms
• Hobby or craft rooms, and
• Chemical storage areas
If air is exposed to the following substances, it should not be used for combustion air, and outdoor air may be required for combustion:
• Permanent wave solutions
• Chlorinated waxes and cleaners
• Chlorine based swimming pool chemicals
• Water softening chemicals
• De-icing salts or chemicals
• Carbon tetrachloride
• Halogen type refrigerants
• Cleaning solvents (such as perchloroethylene)
• Printing inks, paint removers, varnishes, etc.
• Hydrochloric acid
• Cements and glues
• Antistatic fabric softeners for clothes dryers
• Masonry acid washing materials
All fuel-burning equipment must be supplied with air for fuel combustion. Sufficient air must be provided to avoid negative pressure in the
equipment room or space. A positive seal must be made between the furnace cabinet and the return-air duct to prevent pulling air from the burner
area and from draft safeguard opening.
WARNING: CARBON MONOXIDE POISONING HAZARD
The operation of exhaust fans, kitchen ventilation fans, clothes dryers, attic exhaust fans or fireplaces could create a NEGATIVE
PRESSURE CONDITION at the furnace. Make-up air MUST be provided for the ventilation devices, in addition to that required by the
furnace. Refer to the Carbon Monoxide Poisoning Hazard warning in the venting section of these instructions to determine if an
adequate amount of make-up air is available.
The requirements for combustion and ventilation air depend upon whether or not the furnace is located in a space having a volume of at least 50
cubic feet per 1,000 Btuh input rating for all gas appliances installed in the space.
• Spaces having less than 50 cubic feet per 1,000 Btuh require the OUTDOOR COMBUSTION AIR METHOD.
• Spaces having at least 50 cubic feet per 1,000 Btuh may use the INDOOR COMBUSTION AIR, STANDARD or KNOWN-AIR
INFILTRATION METHOD.
Outdoor Combustion Air Method
1. Provide the space with sufficient air for proper combustion, ventilation, and dilution of flue gases using permanent horizontal or vertical
duct(s) or opening(s) directly communicating with the outdoors or spaces that freely communicate with the outdoors.
2. Fig. 18 illustrates how to provide TWO OUTDOOR OPENINGS, one inlet and one outlet combustion and ventilation air openings to the
outdoors.
a. One opening MUST commence within 12" (300 mm) of the ceiling and the second opening MUST commence within 12" (300 mm) of
the floor.
b. Size openings and ducts per Fig. 18 and Table 1.
c. TWO HORIZONTAL DUCTS require 1 square inch of free area per 2,000 Btuh (1,100 mm
appliances in the space per Fig. 18 and Table 1.
d. TWO OPENINGS OR VERTICAL DUCTS require 1 square inch of free area per 4,000 Btuh (550 mm
gas appliances in the space per Fig. 18 and Table 1.

AIR FOR COMBUSTION AND VENTILATION

—20—
2
/kW) of combined input for all gas
2
/kW) for combined input of all