Instruction manual

9
a problem 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 appli-
ances 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 5.3), or
CAN/CGA B149 Installation Codes (Sections 7.2, 7.3, or
7.4), or applicable provisions of the local building codes for
determining the combustion air requirements for the appli-
ances.
Most homes will require outside air be supplied to the
furnace area by means of ventilation grilles or ducts
connecting 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 5.3.
5.3.1 General:
(a) The provisions of 5.3 apply to gas utilization equipment installed
in buildings and which require air for combustion, ventilation
and dilution of flue gases from within the building. They do not
apply to (1) direct vent equipment which is constructed and
installed so that all air combustion is obtained from the outside
atmosphere and all flue gases are discharged to the outside
atmosphere, or (2) enclosed furnaces which incorporate an
integral total enclosure and use only outside air for combustion
and dilution of flue gases.
(b) Equipment shall be installed in a location in which the facilities
for ventilation permit satisfactory combustion of gas, proper
venting and the maintenance of ambient temperature at safe
limits under normal conditions of use. Equipment shall be
located so as not to interfere with proper circulation of air. When
normal infiltration does not provide the necessary air, outside
air shall be introduced.
(c) In addition to air needed for combustion, process air shall be
provided as required for: cooling of equipment or material,
controlling dew point, heating, drying, oxidation or dilution,
safety exhaust, odor control, and air for compressors.
(d) In addition to air needed for combustion, air shall be supplied for
ventilation, including all air required for comfort and proper
working conditions for personnel.
(e) While all forms of building construction cannot be covered in
detail, air for combustion, ventilation and dilution of flue gases
for gas utilization equipment vented by natural draft normally
may be obtained by application of one of the methods covered
in 5.3.3 and 5.3.4.
(f) 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 requirements.
5.3.2 Equipment Located in Unconfined Spaces:
In unconfined spaces (see definition below) 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
If resizing is required on any portion of the venting system,
use the appropriate table in Appendix G in the latest edition
of the National Fuel Gas Code ANSI Z223.1 and/or
CAN/CGA B149 Installation Codes.
THERMOSTAT LOCATION
In an area having good air circulation, locate the thermo-
stat about five feet high on a vibration-free inside wall. Do
not install the thermostat where it may be influenced by any
of the following:
• Drafts, or dead spots behind doors, in corners, or
under cabinets.
• Hot or cold air from registers.
• Radiant heat from the sun.
• Light fixtures or other appliances.
• Radiant heat from a fireplace.
• Concealed hot or cold water pipes, or chimneys.
• Unconditioned areas behind the thermostat, such
as an outside wall.
HOT
COLD
DRAFTS OR DEAD SPOTS
-BEHIND DOORS
-IN CORNERS
-UNDER CABINETS
Thermostat Influences
Consult the instructions packaged with the thermostat for
mounting instructions and further precautions.
V. Combustion and Ventilation Air
Requirements
WARNING
Possible death, personal injury or property
damage 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 to be
supplied to the furnace area.
Improved construction and additional insulation in build-
ings have reduced heat loss by reducing air filtration and
escape around doors and windows. These changes have
helped in reducing heating/cooling costs but have created