Combustion Air And Ventilation For Appliances In Unconfined Spaces; Combustion Air And Ventilation For Appliances In Confined Spaces - Kenmore 153.337113 Owner's Manual

Installation Instructions (cont'd)
Combustion Air and Ventilation
for Appliances Located in
Unconfined Spaces
Unconfined Spac¢ is a space whosevolume is not less than 50
cubic feet per 1,000 Btu per hour of the aggregate input rating
of all appliances instalhd in that space. Roomscommunicating
directly with the space in which the appliances are installed,
through openings not furnished with doors, are considereda
part of the unconfined space
In unconfined spaces in buildings, infiltrationmay be adequate
to provide air for combustion, ventilationand dilution of flue
gases.However,in buildings of tight construction (for example,
weather stripping, heavilyinsulated, caulked, vaporbarrier, etc.),
additional air may need to be provided using the methods
described in Combustion Air and Ventilation for Appliances
Locatedin Confined Spaces,b.
Combustion Air and Ventilation
for Appliances Located in
Confined Spaces
Confined Spacc is a space whose volume is less than 50 cubic
feet per 1,000 Btu per hour of the aggregate input ratingof all
appliances installed in that space.
a. ALL AIR FROM INSIDE BUILDINGS:
(SeePage9 Figure1, and Figure2 below)
The confined space shall be provided with two permanent
openings communicating directlywith 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 ratingofafi
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.
I Figure 2 ]
b. ALL AIR FROM OUTDOORS: (seeFigures 3-5)
The confined space shall be provided with two permanent
openings,one commencing within 12 inches of tee top and
one commencing within 12 inches from the bottom of the
enclosure. The openings shall communicate directly,or by
ducts, with the outdoorsor spaces (crawl or attic) that freely
communicate with the outdoors.
I Figure 3 ]
1. When direcdycommunicating with the outdoors,each open-
ing shall have a minimumflee area of I square inch per 4,000
BTU per hour of total input raring of all equipment in the
enclosure. (See Figure3.)
2. When communicatingwith the outdoors through vertical
ducts, each opening shall have a minimum free area of 1
sc!uareinch per 4,000 BTU per hour of total input ratingof
all equipment in the enclosure.(SeeFigure 4.)
1o
Figure 4 ]
3. When communicating with the outdoors through horizontal
ducts, each opening shall have a minimum free area of 1
square inch per 2,000 BTU per hour of total input rating of
all equipment in the endosure. (See Figure5.)
[el,-- ....
_i " ....... Ii f I
4.When ductsare used, they shall be of the same cross-sectional
area as the free area of the openings to which they connect.
The minimum short side dimensionof rectangular air ducts
shall not be lessthan 3 inches.(SeeFigure5.)
5. Louversand Grilles: In calculating free area, consideration
shall be given to the blocking effect of louvers, grilles or
screensprotecting openings.Screens used shall not be smaller
than ¼ inch mesh. If the _ee area through a desi_ of louver
or grille is known, it should be used in calculating the size
opening recLuired t o provide the free area specified. If the
designand free area is not known, it may be assumed that
wood louverswill be 20-25 percent free areaand metallouvers
and grilles will have 60-75 percent free area. Louversand
grillesshall be fixed in the open position or interlocked with
the .equipment so.that they are opened automatically during
equipmentoperation.
6. Special Conditions Created by Mechanical Exhaustingor
Fireplaces:Operation of exhaust fans, ventilation systems,
clothes dryersor fireplacesmay create conditions requiring
specialattention to avoid unsatisfactoryoperationof installed
gasutilizationequipment.