Intertek ACVC96 Service Instructions Manual page 17

INSTALLATION CONSIDERATIONS
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
The optional CTK0*** thermostat kit may be used with
ComfortNet™ compatable furnaces (ACVC, AMVC, GCVC,
GMVC models). Refer to System Operation - ComfortNet™
System for details.
NOTE: A single-stage thermostat with only one heating
stage can be used to control a two-stage furnace. The ap-
plication of a single-stage thermostat does not offer "true"
thermostat driven two-stage operation, but provides a timed
transition from low to high fire. The furnace will run on low
stage for a fixed period of time before stepping up to high
stage to satisfy the thermostat's call for heat. The delay
period prior to stepping up can be set at either 5 or 10 min-
utes through the DIP switch adjacent to the Heat Off delay
DIP switches on the integrated control module. To use a
single-stage thermostat, turn off power to the furnace, move
the thermostat selection jumper on the integrated contro
module from the "two-stage" position to the "single-stage"
position, turn power back on. Refer to DIP switch charts on
pages 41 & 42.
NOTE: A single-stage thermostat with only one heating stage
may be used to control ComfortNet™ compatible furnaces
(ACVC, AMVC, GCVC, GMVC models). The application of
a single-stage thermostat does not offer "true" thermostat-
driven two-stage operation, but provides a timed transition
from low to high fire. The furnace will run on low stage for a
fixed period of time before stepping up to high stage to sat-
isfy the thermostat's call for heat. The delay period prior to
stepping up can be set at either a fixed 5 minute time delay
or a load based variable time between 1 and 12 minutes
(AUTO mode). If the AUTOmode is selected, the control
averages the cycle times of the previous three cycles and
uses the average to determine the time to transition from
low stage to high stage.
To use a single-stage thermostat, turn off power to the fur-
nace, move the thermostat selection DIP switch to the OFF
position. Set the desired transition time by setting the tran-
sition delay DIP switch to the desired ON/OFF position. Turn
power back on. Refer to DIP switch charts on pages 41 &
42.
Dehumidistat Requirements
A dehumidistat can be used in conjunction with the two-
stage variable speed furnace to lower the humidity in the
conditioned space. The dehumidistat will improve dehumidi-
fication of the conditioned air by prompting the furnace to
reduce the speed of the circulator blower during operation in
the cooling mode. To be compatible with these furnaces, a
dehumidistat must operate on 24 VAC and utilize a switch
which opens on humidity rise. Refer to Electrical Connec-
tions - 24 Volt Dehumidistat Wiring section in this manual
or the installation instructions for correct installation proce-
dure.
Thermostat and Dehumidistat Location
In an area having good air circulation, locate the thermostat
and dehumidistat (if applicable) about five feet high on a vi-
bration-free inside wall. Do not install the thermostat or de-
humidistat where it may be influenced by any of the follow-
ing:
• Drafts, or dead spots behind doors, in corners, or un-
der 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
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 es-
cape around doors and windows. These changes have helped
in reducing heating/cooling costs but have created a prob-
lem 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) fur-
nace, no special provisions for air for combustion are re-
quired. 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 ven-
tilation air for the other appliances. Refer to the latest edi-
tion of the National Fuel Gas Code NFPA 54/ANSI Z223.1
(Section 9.3), or CAN/CGA B149 Installation Codes (Sec-
tions 7.2, 7.3, or 7.4), or applicable provisions of the local
building codes for determining the combustion air require-
ments for the appliances.
WARNING
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