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Installation Instructions (cont'd)
Facts to Consider About the
Location (cont'd)
Combustion Air and
Ventilation for Appliances
Located in Unconfined Spaces
®
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 communicating
directly with the space in which the appliances are installed,
through openings not furnished with doors, are considered a
part of the unconfined space
Figure 2 ]
ROOM INSTALLATION
(ACCEPTABLE)
A room is any enclosure which is at least 16" times
greater than the total volume of all the gas fired appli-
ances within the enclosure.
In unconfined spaces in buildings, infiltration may be adequate
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 Appliances
Located in Confined Spaces, b.
WATER
HEATER
I Figuro 3 I
ALCOVE INSTALLATION
(ACCEPTABLE)
An alcove suitable for the installation of a water heater is a
restricted section of a room not separated from the room
by a door or partition and which meets the minimum
clearances for the specific model water heater listed
below.
*When the ceiling height exceeds 8 feet, you are only
allowed to consicTer8 _'eetwhen calculating the total vol-
ume of the enclosure.
12" MAX.
- r_
t
VENTILATION
AIR
OPENINGS C
DOOR
FRONT VIEW _ 3"MIN.
OF DOOR AIR DUCT
IFig-ro4] [Flguro51
AWARNING
Minimum clearances between the water heater and
combustible construction are listed below:
Minimum Side & Rear Clearances -- I"
Minimum front clearance from jacket to closet door _ 4"
Minimum ceiling clearance from jacket top to com-
bustible ceiling- 18".
It
Combustion Air and
Ventilation for Appliances
Located in Confined Spaces
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
app]iances installed in that space.
ao
ALL AIR FROM INSIDE BUILDINGS:
(See Figures l through 6)
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 all gas utilization equipment installed in the com-
bined space shall be considered in making this determination.
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 commencing within 12 inches
of the bottom of the enclosure.
Figure 6 ]
SVENT
FURN OPENINGS
A _Z] WAI I I _._ER _
b. ALL AIR FROM OUTDOORS: (see Figures 7 through 9,
page 12)
The confined space shall be provided with two permanent
openings, one commencing within 12 inches of me top and
one commencing within 12 inches from the bottom of the
enclosure. The openings shall communicate directly, or by
ducts, with the outdoors or spaces (crawl or attic) that freely
communicate with the outdoors.