Furnace Location Relative To Cooling Equipment; Hazardous Locations; Air For Combustion And Ventilation; General - Bryant 345MAV Installation, Start-Up, And Operating Instructions Manual

• be provided with ample space for servicing and cleaning.
Always comply with minimum fire protection clearances
shown on the furnace clearance-to-combustibles label.
NOTE: For upflow/downflow applications install furnace so that
it is level or pitched forward within 1/2-in. for proper furnace
operation. For horizontal applications pitch 1/4-in. minimum to
1/2-in. maximum forward to ensure proper condensate drainage
from secondary heat exchangers. (See Fig. 13.)
When a furnace is installed so that supply ducts carry air circulated
by the furnace to areas outside the space containing the furnace,
the return air shall also be handled by duct(s) sealed to furnace
casing and terminating outside the space containing the furnace to
ensure there will not be a negative pressure condition within
equipment room or space.
CAUTION: This gas furnace may be used for construction heat provided that:
-The furnace is permanently installed with all electrical wiring, piping, venting and ducting installed according to these installation
instructions. A return air duct is provided, sealed to the furnace casing, and terminated outside the space containing the furnace. This
prevents a negative pressure condition as created by the circulating air blower, causing a flame rollout and/or drawing combustion
products into the structure.
-The furnace is controlled by a thermostat. It may not be hot wired to provide heat continuously to the structure without thermostatic
control.
-Clean outside air is provided for combustion. This is to minimize the corrosive effects of adhesives, sealers and other construction
materials. It also prevents the entrainment of drywall dust into combustion air, which can cause fouling and plugging of furnace
components.
-The temperature of the return air to the furnace is no less than 55°F, with no evening setback or shutdown. The use of the furnace while
the structure is under construction is deemed to be intermittent operation per our installation instructions.
-The air temperature rise is within the rated rise range on the furnace rating plate, and the firing rate has been set to the nameplate value.
-The filters used to clean the circulating air during the construction process must be either changed or thoroughly cleaned prior to
occupancy.
-The furnace, ductwork and filters are cleaned as necessary to remove drywall dust and construction debris from all HVAC system
components after construction is completed.
CAUTION: Do not install furnace in a corrosive or
contaminated atmosphere. Make sure all combustion and
circulating air requirements are met. Failure to follow this
caution will result in intermittent unit operation or per-
formance satisfaction.
CAUTION: If these furnaces are installed in an uncon-
ditioned space where ambient temperatures may be 32°F
or lower, freeze protection measures must be taken. (See
Fig. 15.) Failure to follow this caution will result in minor
property damage.
II. FURNACE LOCATION RELATIVE TO COOLING
EQUIPMENT
The cooling coil must be installed parallel with or on downstream
side of furnace to avoid condensation in heat exchanger. When
installed parallel with a furnace, dampers or other means used to
control flow of air shall be adequate to prevent chilled air from
entering furnace. If dampers are manually operated, they must be
equipped with a means to prevent operation of either unit unless
damper is in full-heat or full-cool position.
32 F MINIMUM INSTALLED
AMBIENT OR FREEZE
PROTECTION REQUIRED
Fig. 15—Freeze Protection
III. HAZARDOUS LOCATIONS
WARNING: When the furnace is installed in a residen-
tial garage, it must be installed so that burners and
ignition sources are located a minimum of 18 in. above
floor. The furnace must be located or protected to avoid
physical damage by vehicles. When furnace is installed in
a public garage, airplane hangar, or other building having
a hazardous atmosphere, unit must be installed in accor-
dance with requirements of National Fire Protection
Association, Inc. (See Fig. 16.)

AIR FOR COMBUSTION AND VENTILATION

I. GENERAL
Provisions for adequate combustion and ventilation air must be
provided in accordance with Section 5.3, Air for Combustion and
Ventilation, of the NFGC or applicable provisions of the local
building codes.
Canadian installations must be in accordance with Section 7.2 of
the Air Supply Determination for Central Heating Furnaces,
Boilers, and Hot Water Heaters, and 7.3, Air Supply Openings and
Ducts, of the NSCNGPIC and all authorities having jurisdiction.
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