8
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
W A R N IN G
T
O A V O ID P R O P E R T Y D A M A G E , P E R S O N A L IN J U R Y O R D E A T H , S U F F IC IE N T
F R E S H A IR F O R P R O P E R C O M B U S T IO N A N D V E NT IL A T IO N O F F L U E G AS E S M U S T
B E S U P P L IE D .
M
O S T H O M E S R E Q U IR E O U T S ID E A IR B E S U P P L IE D IN T O T HE
F U R N A CE A RE A .
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.
House depressurization can cause back drafting or improper
combustion of gas-fired appliances, thereby exposing building
occupants to gas combustion products that could include carbon
monoxide.
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/CSA 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.
This furnace must use indoor air for combustion. It cannot be
installed as a direct vent (i.e., sealed combustion) furnace.
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 for 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.
The following vent testing procedure is reproduced from the
American National Standard/National Standard of Canada for
Gas-Fired Central Furnaces ANSI Z21.47b-2002, CSA-2.3b-2002
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 CAN/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
inspected in operation. Adjust thermostat so appliance shall
operate continuously;
e. Test for draft hood equipped appliance 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 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 CAN/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 CAN/CSA B149 Installation
Codes.
T
HERMOSTAT
L
OCATION
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, such as an
outside wall.
