SYSTEM OPERATION
10
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 G*ES9* and A*ES9* 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
dehumidistat, such as an outside wall.
COMBUSTION AND VENTILATION AIR
REQUIREMENTS
WARNING
P
O
SSI
B
LE PR
O
PER
TY
DAMAGE
,
PERS
O
NAL INJ
U
R
Y
O
R DEA
TH
MA
Y
O
CC
U
R
I
F
TH
E
FU
RNACE IS N
OT
PR
O
VIDED WI
TH
EN
OU
G
H
F
RES
H
AIR
FO
R PR
O
PER
C
O
M
BU
S
T
I
O
N AND VEN
T
ILA
T
I
O
N
OF
F
L
U
E GASES
.
M
O
S
T
HO
MES REQ
U
IRE
OUT
SIDE AIR
B
E S
U
PPLIED
TO
TH
E
FU
RNACE 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.
However, 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 ap-
pliances.
9.3.1.2
Appliances of other than natural draft design and other than
Category 1 vented appliances shall be provided with combustion,
ventilation, and dilution air in accordance with the appliance man-
ufacturer’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 considered 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 open-
ings 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).
