One Permanent Opening Method; Engineered Installations; Mechanical Combustion Air Supply - Goodman GMEC96 Series Service And Troubleshooting

SYSTEM OPERATION
The openings shall communicate directly, or by ducts, with the
outdoors or spaces that freely communicate with the outdoors, as
follows:
(1)* Where directly communicating with the outdoors or where com-
municating to the outdoors through vertical ducts, each opening
shall have a minimum free area of 1 in.
kW) of total input rating of all appliances in the enclosure. [See
Figure A.9.3.3.1(1)(a) and Figure A.9.3.3.1(1)(b).]
Chimney or Gas Vent
Water
Heater
Furnace
Alternate
air inlet
Ventilation louvers for
unheated crawl space
Figure A.9.3.3.1(1)(a) All Combustion Air From Outdoors -
Inlet Air from Ventilated Crawl Space and Outlet Air
to Ventilated Attic.
Chimney or Gas Vent
Ventilation louvers
(each end of attic)
Water
Heater
Furnace
Figure A.9.3.3.1(1)(b) All Combustion Air
From Outdoors through Ventilated Attic.
(2)* Where communicating with the outdoors through horizontal
ducts, each opening shall have a minimum free area of 1
in. /2000 Btu/hr (1100 min
2
ances in the enclosure. [See Figure A.9.3.3.1(2).]
Chimney or Gas Vent
Outlet air duct
Water
Heater
Furnace
Inlet air duct
Figure A.9.3.3.1(2) All Combustion Air From Outdoors
through Horizontal Ducts.
12
/4000 Btu/hr (550 min
2
Ventilation louvers
(each end of attic)
NOTE: The inlet and outlet air
openings must each have a free
area of not less than one square
inch per 4000 BTU of the
total input rating of all equipment
in the enclosure.
Outlet Air
Inlet Air
NOTE: The inlet and outlet air
openings must each have a free
area of not less than one square
inch per 4000 BTU of the
total input rating of all equipment
in the enclosure.
Outlet Air
Inlet air duct
[ends 1 ft (300 mm)
above floor]
/kW) of total input rating of all appli-
2
NOTE: The air duct openings
must have a free area of not
less than one square inch per
2000 BTU of the total input
rating of all equipment in the
enclosure*.
9.3.3.2* One Permanent Opening Method. One permanent open-
ings, 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 communicate through a vertical or horizontal
/ duct to the outdoors or spaces that freely communicate with the
2
outdoors (see Figure A.9.3.3.2) and shall have a minimum free area
of the following:
(1) 1 in. /3000 Btu/hr (700 mm
2
all appliances located in the enclosure, and
(2) Not less than the sum of the areas of all vent connectors in the
space.
NOTE: The single opening must have
a free area of not less than one
square inch per 3000 BTU of
the total input rating of all equip-
ment in the enclosure, but not less than
the sum of the areas of all vent
connectors in the confined 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
calculated in accordance with the following:
(a) The ratio of the interior spaces shall be the available vol-
ume of all communicating spaces divided by the required
volume.
(b) The outdoor size reduction factor shall be 1 minus the ratio
of interior spaces.
(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 instal-
lations 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
min per 1000 Btu/hr (0.034 m
within the space.
9.3.6.1 Where exhaust fans are installed, additional air shall be
provided to replace the exhausted air.
per kW) of the total input rating of
2
Chimney or Gas Vent
Opening
Alternate
Water
Opening
Heater
Location
Furnace
/min per kW) for all appliances located
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