7
Combustion Air Supply and
Ventilation
IMPORTANT: Air for combustion and ventilation must not
come from a corrosive atmosphere. Any failure due to
corrosive elements in the atmosphere is excluded from
warranty coverage.
The following types of installation (not limited to the
following) will require outdoor air for combustion due to
chemical exposure and may reduce but not eliminate the
presence of corrosive chemicals in the air:
• beauty shops
• photo processing labs
• buildings with indoor pools
• water heaters installed in laundry, hobby, or craft rooms
• water heaters installed near chemical storage areas
Combustion air must be free of acid-forming chemicals
such as sulfur, fluorine, and chlorine. These elements are
found in aerosol sprays, detergents, bleaches, cleaning
solvents, air fresheners, paint, and varnish removers,
refrigerants, and many other commercial and household
products. When burned, vapors from these products form
highly corrosive acid compounds. These products should
not be stored or used near the water heater or air inlet.
Combustion and ventilation air requirements are
determined by the location of the water heater. The water
heater may be located in either an open (unconfined) area
or in a confined area or small enclosure such as a closet or
small room. Confined spaces are areas with less than 50
cubic feet for each 1,000 BTUH of the total input for all gas-
using appliances.
Carbon Monoxide Warning
Follow all the local and state codes or, in
the absence of local and state codes, the
“National Fuel Gas Code”, ANSI Z223.1
(NFPA 54)- latest edition to properly install
vent system.
Failure to do so can result in death,
explosion, or carbon monoxide poisoning.
WARNING