Goodman ACS series Service Instructions Manual page 32

PRODUCT DESIGN
Consult the instructions packaged with the thermostat and
dehumidistat for mounting instructions and further precau-
tions.
COMBUSTION AND VENTILATION AIR
REQUIREMENTS
P
OSSIBLE PROPERTY DAMAGE, PERSONAL INJURY OR DEATH MAY OCCUR
IF THE FURNACE IS NOT PROVIDED WITH ENOUGH FRESH AIR FOR PROPER
COMBUSTION AND VENTILATION OF FLUE GASES. MOST HOMES REQUIRE
OUTSIDE AIR BE SUPPLIED TO THE FURNACE AREA.
Improved construction and additional insulation in buildings
have reduced heat loss by reducing air infiltration and es-
cape around doors and windows. These changes have helped
in reducing heating/cooling costs but have created a prob-
lem supplying combustion and ventilation air for gas fired
and other fuel burning appliances. Appliances that pull air
out of the house (clothes dryers, exhaust fans, fireplaces,
etc.) increase the problem by starving appliances for air.
If this furnace is to be installed in the same space with other
gas appliances, such as a water heater, ensure there is an
adequate supply of combustion and ventilation air for the
other appliances. Refer to the latest edition of the National
Fuel Gas Code NFPA 54/ANSI Z223.1 (Section 9.3), or CAN/
CGA B149 Installation Codes (Sections 7.2, 7.3, or 7.4), or
applicable provisions of the local building codes for deter-
mining the combustion air requirements for the appliances.
Most homes will require outside air be supplied to the fur-
nace area by means of ventilation grilles or ducts connect-
ing directly to the outdoors or spaces open to the outdoors
such as attics or crawl spaces.
The following information on air for combustion and ventilation
is reproduced from the National Fuel Gas Code NFPA 54/ANSI
Z223.1 Section 9.3.
9.3* Air for Combustion and Ventilation.
9.3.1 General.
9.3.1.1 Air for combustion, ventilation, and dilution of flue gases for
appliances installed in buildings shall be obtained by application of one
of the methods covered in 9.3.2 through 9.3.6. Where the requirements
of 9.3.2 are not met, outdoor air shall be introduced in accordance with
methods covered in 9.3.3 through 9.3.6.
Exception No. 1: This provision shall not apply to direct vent appliances.
9.3.1.2 Appliances of other than natural draft design and other than
Category 1 vented appliances shall be provided with combustion, ven-
tilation, and dilution air in accordance with the appliance manufacturer's
instructions.
9.3.1.3 Appliances shall be located so as not to interfere with proper
circulation of combustion, ventilation, and dilution air.
9.3.1.4 Where used, a draft hood or a barometric draft regulator shall be
installed in the same room or enclosure as the appliance served so as to
prevent any difference in pressure between the hood or regulator and the
combustion air supply.
32
WARNING
9.3.1.5 Makeup air requirements for the operation of exhaust fans, kitchen
ventilation systems, clothes dryers, and fireplaces shall be considered in
determining the adequacy of a space to provide combustion air require-
ments.
9.3.2 Indoor Combustion Air. The required volume of indoor air shall
be determined in accordance with the method in 9.3.2.1 or 9.3.2.2 ex-
cept that where the air infiltration rate is known to be less than 0.40
ACH, the method in 9.3.2.2 shall be used. The total required volume
shall be the sum of the required volume calculated for all appliances
located within the space. Rooms communicating directly with the space
in which the appliances are installed through openings not furnished
with doors, and through combustion air openings sized and located in
accordance with 9.3.2.3, are considered a part of the required volume.
9.3.2.1* Standard Method. The minimum required volume shall be 50
ft per 10000/Btu/hour (4.8m
3
9.3.2.2* Known Air Infiltration Rate Method. Where the air infiltra-
tion rate of a structure is known, the minimum required volume shall be
determined as follows:
(1) For appliances other than fan-assisted, calculate using the following
equation:
Required Volume > ________ _________
other
(2) For fan-assisted appliances, calculate using the following equation:
Required Volume > ________ _________
fan
where:
I = all appliances other than fan-assisted input in Btu per
other
hour
I = fan-assisted appliances input in Btu per hour
fan
ACH = air change per hour (percent of volume of space exchanged
per hour, expressed as a decimal)
(3) For purposes of this calculation, an infiltration rate greater than
0.60 ACH shall not be used in the equations in 9.3.2.2(1) and
9.3.2.2(2).
9.3.2.3 Indoor Opening Size and Location. Openings used to connect
indoor spaces shall be sized and located in accordance with the follow-
ing:
(1)*Combining spaces on the same story. Each opening shall have a
minimum free area of 1 in.
input rating of all appliances in the space but not less than 100 in.
(0.60m ). One opening shall commence within 12 in. (300 mm) of
2
the top, and one opening shall commence within 12 in. (300 mm) of
the bottom, of the enclosure [see Figure A.9.3.2.3(1)]. The mini-
mum dimension of air openings shall be not less than 3 in. (80 mm).
/kW).
3
)
(
21 ft I
3
other
ACH 1000 Btu/hr
(
)
15 ft I
3
fan
ACH 1000 Btu/hr
/1000Btu/hr (2200 mm /kW) of the total
2 2
2