PRODUCT DESIGN
19
Furnace Suspension
If suspending the furnace from rafters or joist, use 3/8"
threaded rod and 2”x2”x1/8” angle iron as shown in the
following figure. If the furnace is installed in a crawl space it
must also be suspended from the floor joist or supported by
a concrete pad. Never install the furnace on the ground or
allow it to be exposed to water. The length of rod will depend
on the application and the clearances necessary.
Suspended Furnace
E
xisting
F
urnacE
r
Emoval
NOTE:
When an existing furnace is removed from a venting
system serving other appliances,
the venting system may be
too large to properly vent the remaining attached appliances.
The following vent testing procedure is repro duced from the
American National Standard/National Standard of Canada
for Gas-Fired Central Furnaces ANSI Z21.47, latest edition,
CSA-2.3b, latest edition Section 1.23.1.
The following steps shall be followed with each appliance connected to the
venting system placed in operation, while any other appliances connected
to the venting system are not in operation:
a. Seal any unused openings in the venting system;
b. Inspect the venting system for proper size and horizontal pitch,
as required by the National Fuel Gas Code, ANSI Z223.1 or the
CSA B149 Installation Codes and these instructions. Determine
that there is no blockage or restriction, leakage, corrosion and
other deficiencies which could cause an unsafe condition;
c. In so far as practical, close all building doors and windows and
all doors between the space in which the appliance(s) connected
to the venting system are located and other spaces of the building.
Turn on clothes dryers and any appliance not connected to the
venting system. Turn on any exhaust fans, such as range hoods
and bathroom exhausts, so they shall operate at maximum speed.
Do not operate a summer exhaust fan. Close fireplace dampers;
d. Follow the lighting instructions. Place the appliance being in-
spected in operation. Adjust thermostat so appliance shall operate
continuously;
e. Test for draft hood equipped spillage at the draft hood relief opening
after 5 minutes of main burner operation. Use the flame of a match
or candle;
f. After it has been determined that each appliance connected to
the venting system properly vents when tested as outlined above,
return doors, windows, exhaust fans, fireplace dampers and any
other gas burning appliance to their previous conditions of use;
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 common termi-
nal is recommended.
Thermostat Location
In an area having good air circulation, locate the thermostat
and dehumidistat (if applicable) about five feet high on a
vibration-free inside wall. Do not install the thermostat or de-
humidistat 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 de-
humidistat, such as an outside wall.
Consult the instructions packaged with the thermostat and
dehumidistat for mounting instructions and further precau-
tions.
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.
