Carrier Infinity ICS 58MVC 100 Series Installation Instructions Manual page 35

AIR
INTAKE HOUSING
3/8" ID TUBE
3/16"
DRILL
TO OPEN
DRAIN
BURNER
BOX
_COMBUSTION
AIR PIPE
A93035
Fig. 40 - Intake
Housing Plug Fitting Drain
8. Install casing hole filler cap (factory-supplied in loose
parts bag) in unused combustion air pipe casing hole.
Attachment of Combustion Air Intake Housing Plug Fitting
The combustion-air intake plug fitting nmst be installed in
unused combustion air intake housing. This fitting nmst be
attached by using RTV sealant, or by drilling a 1/8-in. hole in
fitting, using hole in intake housing as a guide. Install a
field-supplied No. 6 or No. 8 sheet metal screw.
NOTE: DO NOT OVER-TIGHTEN SCREW. Breakage of
intake housing or fitting may cause air leakage to occur.
A plugged drain connection has been provided on this fitting for
use when moisture is found in combustion air intake pipe and
combustion box.
If use of this drain connection is desired, drill out fitting's tap
plug with 3/16-in. drill and connect a field-supplied 3/8-in. tube.
This tube should be routed to open condensate drain for furnace
and A/C (if used), and should be trapped, as shown in Fig. 40.
NOTE: (Direct Vent / 2-Pipe System ONLY). Moisture in
combustion air intake may be a result of improper ternfination.
Ensure combustion air pipe ternfination is sinfilar to those as
shown in Fig. 36 so that it will not be susceptible to area where
light snow or others sources of moisture could be pulled in.
Combustion Air Termination - Ventilated Combustion Air
Option
Provisions for adequate combustion, ventilation, and dilution air
must be provided in accordance with:
• U.S. Installations: Section 9.3 NFPA 54/ANSI
Z223.1-2006, Air for Combustion and Ventilation and
applicable provisions of the local building codes.
• Canadian Installations: Part 8 of CAN/CS-B149.1-05.
Venting Systems and Air Supply for Appliances and all
authorities having jurisdiction.
Combustion air is piped directly to the burner box on furnace
using the same materials used to vent the furnace. (See Table 5.)
The combustion air pipe is ternfinated in an attic or crawl space
that is well ventilated with OUTDOOR AIR and is well isolated
from the living space or garage. If the furnace is installed in a well
ventilated attic, crawlspace or other enclosure, the combustion air
pipe can be ternfinated in the same space.
[]NIT CORROSION HAZARD
Failure to follow this caution may result in reduced furnace
component life.
Air for combustion nmst not be contanfinated by halogen
compounds, which include fluoride, chloride, bronfide, and
iodide. These elements may corrode heat exchangers and
shorten furnace life. Air contanfinants are found in aerosol
sprays, detergents, bleaches, cleaning solvents, salts, air
fresheners, and other household products.
The combustion air pipe cannot be ternfinated in attics or
crawlspaces that use ventilation fans designed to operate during
the heating season. If ventilation fans are present in these areas,
the combustion air pipe must ternfinate outdoors as a Direct Vent/
2-Pipe system.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal
iniury or death.
The operation of exhaust fans, kitchen ventilation fans,
clothes dryers, attic exhaust fans or fireplaces could create a
NEGATIVE PRESSURE CONDITION at the furnace.
Makeup air MUST be provided for the ventilation devices,
in addition to that required by the furnace. Refer to the
Carbon Monoxide Poisoning Hazard warning at the end of
this section to deternfine if an adequate amount of make-up
air is available.
NOTE: Combustion air pipe must have the same diameter as
vent pipe.
An attic or crawlspace may be considered a space that freely
communicates with the outdoors provided there are adequate
permanent ventilation openings directly to outdoors having free
area of at least 1-in.2/4,000 Btuh of total input rating for all gas
appliances in the space.
NOTE: In deternfining the free area of an opening, the blocking
effect of the louvers, grilles, and screens nmst be considered. If
the free area of a louver or grille design is unknown, it may be
assumed that wood louvers have a 20 percent free area, and metal
louvers or grilles have a 60 percent free area. Screens, when used,
must not be smaller than l/4-in, mesh. Louvers and grilles must
be constructed so they cannot be closed.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal
iniury or death.
Many homes require air to be supplied from outdoors for
furnace combustion, ventilation, and dilution of flue gases.
The furnace combustion air supply must be provided in
accordance with this instruction manual.
g
Attic terminations require at least (1) 90 degree elbow, with the
open end pointing horizontally or downward. The open end of
the elbow must be at least 12-in. (305 ram) above any insulation
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