Kenmore 153.33439, 153.33459 Installation Instructions contd, ALL AIR from Inside Buildings

Installation Instructions (cont'd)

Combustion Air and Ventilation

for Appliances Located in Unconfined Spaces

Uncomemed 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.

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 Locate.din Confined Spaces, b.

1.When directly communicating with the outdoors each open- in._ shall have a minimum free area of 1 square inch per 4,000 BI w per hour of total input rating of all equipment in the enclosure. (See Figure 3.)

2.When communicating with the outdoors through vertical ducts, each opening shall have a minimum free area of 1

square inch per 4,000 BTU per hour of total input rating of all equipment in the enclosure. (See Figure 4.)

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 Bru per hour of the aggregate input rating of all appliances installed in that space.

a. ALL AIR FROM INSIDE BUILDINGS:

(See Page 9 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 all sas 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 I00 square inches. One opening shall commence within

12 ....	me	"	"	12"	of the bot-
m		top ano	one commencing within
tom of	the	enclosure.

I Figure 2 ]

b. ALL AIR FROM OUTDOORS: (see Figures 3-5)

The confined space shall be provided ,with two permanent openings, one commencing within 12 of the top and one commencing within 12" from the bottom of the enclosure. The openings shall communicate directly, or by ducts, with

the outdoors or spaces (crawl or attic) that freely communi- cate Withthe outdoors.

Figure q

Figure 4 }

3.When communicating with the outdoors through horizontal ducts, each opening shall have a minimum flee area of 1

square inch per 2,000 BTU per hour of toral input rating of all equipment in the enclosure. (See Figure 5.)

4.When ducts are 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 dimension of rectangular air ducts shall not be less than 3". (See Figure 5.)

5, Louvers and Grilles: In calculating free area, consideration

shall be given to the blocking effect of louvers, grilles or screens protecting openings. Screens used shall not be smaller

than ¼-mesh. Iftbe free area through a design of louver or grille is known, it should be used in calculating the size open- ing required to provide the free area specified. If the design and free area is not known, it may be assumed that wood lou- vers will be 20-25 percent free area and metal louvers and

grilles will have 60-75percent free area. Louvers and grilles shall be fixed in the open position or interlocked with the

equipment so that they are opened automatically during equipment operation.

6. Special Conditions Created by Mechanical Exhausting or

Fireplaces: Operation of exhaust fans, ventilation systems,

clothes dryers or fireplaces may create conditions requirin[_ special attention to avoid unsatisfactory operation of installecl

gas utilization equipment.

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