Instructions | for | Installation (cont'd) | |
Locating | the New | Water | Combustion Air and Ventilation |
Heater | (cont'd) |
| for Appliances Located in |
|
|
| Unconfined Spaces |
&WARNING
If this water heater will be used in beauty shops, barber shops, cleaning establishments, or
ice laundries with dry cleaning equipment, it is
imperative that the water heater or water heaters be installed so that combustion and ventilation air
be taken from outside these areas. Refer to the
"Locating The New Water Heater" section of this
manual and also the latest edition of the National Fuel Gas Code, ANSI Z223.1, also referred to as NFPA
54 for specifics provided concerning air required,
Unconfined Space is a space whose volume is not less than
50 cubic feet per 1,000 Btu per hour of the aggregate input rating of all appliances installed in that space. Rooms com
mnnicating directly with the space in which the appliances are installed, through openings not furnished with doors, are con-
sidered a part of the unconfined space
In unconfined spaces in buildings, infiltration may be ade- quate to provide air for combustion, ventilation and dilution
of flue gases. However, in buildings of tight construction (for example weather stripping heavily insulated, caulked, vapor
barrier, etc.), additional air may need to be provided using the methods described in Combustion Air and Ventilation for
&WARNING
Appliances Located in Confined Spaces, b.
INSTALLATIONS IN AREAS WHERE FLAMMABLE
(GARAGES, STORAGE, AND UTILITY AREAS, ETC): I Flammable liquids (such as gasoline, solvents, propane I
(LP) or butane, etc.), all of which emit flammable I vapors, may be improperly stored or used in such
areas. The gas water heater pilot light or main burner
can ignite such vapors. The resulting flashback and fire can cause death or serious burns to anyone in the
area, as well as property damage,
If installation in such areas is your only option, then
the installation must be accomplished in a way that the pilot flame and main burner flame are elevated
from the floor at least 18 inches. While this may reduce the chances of flammable vapors from a floor
spill being ignited, gasoline and other flammable sub- stances should never be stored or used in the same
room or area containing a gas water heater or other open flame or spark producing appliance,
NOTE: Flammable vapors may be drawn by air currents
from other areas of the structure to the appliance,
Combustion Air and Ventilation
A__ __ I- i
for /ppllances Located in
Confined =paces
Confined Space is a space whose volume is less than 50 cubic
feet per 1,000 Btu per hour of the aggregate input rating of all appliances installed in that space.
a. ALL AIR FROM INSIDE BUILDINGS:
(See Page 10 Figure 1, and Figure 2 below)
The confined space shall be provided with two permanent openings communicating directly with an additional
room(s) of sufficient volume so that the combined volume of all spaces meets the criteria for an unconfined space. The total input of an gas utilization equipment installed in the combined space shall be considered in making this deter- mination. Each opening shall have a minimum free area of one square inch per 1,000 BTU per hour of the total input rating of all gas utilization equipment in the confined space, but not less than 100 square inches. One opening shall commence within 12 inches of the top and one com- mencing within 12 inches of the bottom of the enclosure.
FUR W/_TER OPENINQ8
R
[ Figure 2 ]
11