INSTALLATION CONSIDERATIONS
12
g. If improper venting is observed during any of the above tests,
the common venting system must be corrected.
Corrections must be in accordance with the latest edition of
the National Fuel Gas Code NFPA 54/ANSI Z223.1 and/or
CSA B149 Installation Codes.
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 CSA B149
Installation Codes.
Thermostat Requirements
A high quality single stage thermostat with a "C" terminal is
recommended to control the DM92SE furnace.
Thermostat Location
In an area having good air circulation, locate the thermostat
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 and dehu
-
midistat, such as an outside wall.
COMBUSTION AND VENTILATION AIR
REQUIREMENTS
WARNING
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 escape
around doors and windows. These changes have helped in
reducing heating/cooling costs but have created 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 appliances for air.
When the furnace is installed as a direct vent (2-pipe) furnace,
no special provisions for air for combustion are required. How
-
ever, 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 determining
the combustion air requirements for the appliances.
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 infor mation on air for combustion and ventilation
is repro duced 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, venti-
lation, 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.
9.3.1.5
Makeup air requirements for the operation of exhaust fans,
kitchen ventilation systems, clothes dryers, and fireplaces shall be con
-
sidered in determining the adequacy of a space to provide combustion
air requirements.
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 except
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
3
per 1,000/Btu/hour (4.8m
3
/kW).