Amana xMVM97 series Installation Instructions Manual page 11

Figure A.9.3.3.1(2) All Combustion Air From Outdoors
through Horizontal Ducts.
9.3.3.2* One Permanent Opening Method. One permanent openings,
commencing within 12 in. (300 mm) of the top of the enclosure, shall be
provided. The appliance shall have clearances of at least 1 in. (25 mm)
from the sides and back and 6 in. (150 mm) from the front of the appliance.
The opening shall directly communicate with the outdoors or shall com-
municate through a vertical or horizontal duct to the outdoors or spaces
that freely communicate with the outdoors (see Figure A.9.3.3.2) and shall
have a minimum free area of the following:
(1) 1 in. 2 /3000 Btu/hr (700 mm
appliances located in the enclosure, and
(2) Not less than the sum of the areas of all vent connectors in the space.
Figure A.9.3.3.2 All Combustion Air
From Outdoors through Single Combustion Air Opening.
9.3.4 Combination Indoor and Outdoor Combustion Air. The use of a
combination of indoor and outdoor combustion air shall be in accordance
with (1) through (3) (see example calculation in Annex J]:
(1) Indoor Openings: Where used, openings connecting the interior spaces
shall comply with 9.3.2.3.
(2) Outdoor Opening(s) Location. Outdoor opening(s) shall be located in
accordance with 9.3.3.
(3) Outdoor Opening(s) Size. The outdoor opening(s) size shall be calcu-
lated in accordance with the following:
(a) The ratio of the interior spaces shall be the available volume of
all communicating spaces divided by the required volume.
(b) The outdoor size reduction factor shall be 1 minus the ratio of
interior spaces.
2 per kW) of the total input rating of all
(c) The minimum size of outdoor opening(s) shall be the full size of
outdoor opening(s) calculated in accordance with 9.3.3, multiplied
by the reduction factor. The minimum dimension of air openings
shall not be less than 3 in. (80 mm).
9.3.5 Engineered Installations. Engineered combustion air installations
shall provide an adequate supply of combustion, ventilation, and dilution
air and shall be approved by the authority having jurisdiction.
9.3.6 Mechanical Combustion Air Supply. Where all combustion air is
provided by a mechanical air supply system, the combustion air shall be
supplied form outdoors at the minimum rate of 0.35 ft
3
hr (0.034 m /min per kW) for all appliances located within the space.
9.3.6.1 Where exhaust fans are installed, additional air shall be provided to
replace the exhausted air.
9.3.6.2 Each of the appliances served shall be interlocked to the mechanical
air supply system to prevent main burner operation where the mechanical
air supply system is not in operation.
9.3.6.3 Where combustion air is provided by the building's mechanical
ventilation system, the system shall provide the specified combustion air
rate in addition to the required ventilation air.
9.3.7 Louvers, Grilles, and Screens.
9.3.7.1 Louvers and Grilles. The required size of openings for combus-
tion, ventilation, and dilution air shall be based on the net free area of each
opening. Where the free area through a design of louver or grille or screen is
known, it shall be used in calculating the size opening required to provide
the free area specified. Where the louver and grille design and free area are
not known, it shall be assumed that wood louvers will have 25 percent free
area, and metal louvers and grilles will have 75 percent free area.
Nonmotorized louvers and grilles shall be fixed in the open position.
9.3.7.2 Minimum Scree Mesh Size. Screens shall not be smaller than 1/
4 in. mesh.
9.3.7.3 Motorized Louvers. Motorized louvers shall be interlocked with
the appliance so they are proven in the full open position prior to main
burner ignition and during main burner operation. Means shall be provided
to prevent the main burner form igniting should the louver fail to open
during burner startup and to shut down the main burner if the louvers close
during burner operation.
9.3.8 Combustion Air Ducts. Combustion air ducts shall comply with
9.3.8.1 through 9.3.8.8.
9.3.8.1 Ducts shall be constructed of galvanized steel or a material having
equivalent corrosion resistance, strength, and rigidity.
Exception: Within dwellings units, unobstructed stud and joist spaces shall
not be prohibited from conveying combustion air, provided that not more
than one fireblock is removed.
9.3.8.2 Ducts shall terminate in an unobstructed space, allowing free move-
ment of combustion air to the appliances.
9.3.8.3 Ducts shall serve a single space.
9.3.8.4 Ducts shall not serve both upper and lower combustion air open-
ings where both such openings are used. The separation between ducts
servicing upper and lower combustion air openings shall be maintained to
the source of combustion air.
3 /min per 1000 Btu/
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