
59CU5A: Installation, Start-up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
8
The following types of furnace installations may require OUTDOOR
AIR for combustion due to chemical exposures:
• Commercial buildings
• Buildings with indoor pools
• Laundry rooms
• Hobby or craft rooms
• Chemical storage areas
If air is exposed to the following substances, it should not be used for
combustion air, and outdoor air may be required for combustion:
• Permanent wave solutions
• Chlorinated waxes and cleaners
• Chlorine based swimming pool chemicals
• Water softening chemicals
• De-icing salts or chemicals
• Carbon tetrachloride
• Halogen type refrigerants
• Cleaning solvents (such as perchloroethylene)
• Printing inks, paint removers, varnishes, etc.
• Hydrochloric acid
• Cements and glues
• Antistatic fabric softeners for clothes dryers
• Masonry acid washing materials
All fuel-burning equipment must be supplied with air for fuel
combustion. Sufficient air must be provided to avoid negative pressure
in the equipment room or space. A positive seal must be made between
the furnace cabinet and the return-air duct to prevent pulling air from the
burner area.
Location Relative to Cooling Equipment
The cooling coil must be installed parallel with, or on the downstream
side of the unit to avoid condensation in the heat exchangers. When
installed parallel with the furnace, dampers or other flow control must
prevent chilled air from entering the furnace. If the dampers are
manually operated, they must be equipped with means to prevent
operation of either unit unless the damper is in the full-heat or full-cool
position. Refer to Installation of Evaporator Coil section for install
requirements for unshielded coils, see
AIR FOR COMBUSTION AND
VENTILATION
Introduction
2-pipe Applications
When the furnace is installed as a 2-pipe furnace, no special provisions
for air for combustion are required. However, other gas appliances
installed in the space with the furnace may require outside air for
combustion. Follow the guidelines below to ensure that other gas
appliances have sufficient air for combustion.
1-pipe Applications
When the furnace is installed as a 1-pipe furnace, it will be necessary to
ensure there is adequate air for combustion. Other gas appliances
installed with the furnace may also require air for combustion and
ventilation in addition to the amount of combustion air and ventilation
air required for the furnace. Follow the guidelines below to ensure that
the furnace and other gas appliances have sufficient air for combustion.
Ventilated Combustion Air Applications
When the furnace is installed using the ventilated combustion air option,
the attic or crawlspace must freely communicate with the outdoor to
provide sufficient air for combustion. The combustion air pipe cannot be
terminated 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 terminate outdoors as a 2-Pipe
system.
All air for combustion is piped directly to the furnace from a space that is
well ventilated with outdoor air (such as an attic, crawl space or
equipment closet) and the space is well isolated from the living space or
garage. In addition, other gas appliances installed in the space with the
furnace may require outside air for combustion. Follow the guidelines
below to ensure that the roof or crawlspace walls have sufficient free
area to provide sufficient air for combustion and ventilation for the
furnaces. The guidelines below can be used to ensure that other gas
appliances have sufficient air for combustion.
Provisions for adequate combustion, ventilation, and dilution air must be
provided in accordance with:
• U.S.A. Installations: Current edition of Section 9.3 of the NFPA
54/ANSI Z223.1 , Air for Combustion and Ventilation and applicable
provisions of the local building codes.
WARNING
!
CARBON MONOXIDE POISONING / COMPONENT
DAMAGE HAZARD
Failure to follow this warning could result in personal injury or death
and unit component damage.
Corrosive or contaminated air may cause failure of parts containing flue
gas, which could leak into the living space. Air for combustion must not
be contaminated by halogen compounds, which include fluoride,
chloride, bromide, and iodide. These elements can corrode heat
exchangers and shorten furnace life. Air contaminants are found in
aerosol sprays, detergents, bleaches, cleaning solvents, salts, air
fresheners, and other household products. Do not install furnace in a
corrosive or contaminated atmosphere. Make sure all combustion and
circulating air requirements are met, in addition to all local codes and
ordinances.
WARNING
!
FIRE, INJURY OR DEATH HAZARD
Failure to follow this warning could result in personal injury, death
and/or property damage.
When the furnace is installed in a residential garage, the burners and
burner ignition devices must be located at least 18 in. (457 mm) above
the floor. The furnace must be located or protected to avoid damage by
vehicles. When the furnace is installed in a public garage, airplane
hangar, or other building having a hazardous atmosphere, the furnace
must be installed in accordance with the current edition of NFPA
54/ANSI Z223.1 or CAN/CSA B149.2, see
CAUTION
!
FURNACE CORROSION HAZARD
Failure to follow this caution may result in furnace damage.
Air for combustion must not be contaminated by halogen compounds,
which include fluoride, chloride, bromide, and iodide. These elements
can corrode heat exchangers and shorten furnace life. Air contaminants
are found in aerosol sprays, detergents, bleaches, cleaning solvents,
salts, air fresheners, and other household products.