507762-01
Issue 1907
Page 13 of 46
SUPPLY
AIR
SUPPLY
AIR
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Furnace
Furnace
Figure 20. Duct System and Proper Installation
Supply Air Plenum
If the furnace is installed without a cooling coil, a removable
access panel should be installed in the supply air duct. The
access panel should be large enough to permit inspection
of the heat exchanger. The furnace access panel must
always be in place when the furnace is operating and it
must not allow leaks.
Return Air Plenum
NOTE:
Return air must not be drawn from a room where
this furnace, or any other gas-fueled appliance (i.e., water
heater), or carbon monoxide-producing device (i.e., wood
fireplace) is installed.
When return air is drawn from a room, a negative pressure
is created in the room. If a gas appliance is operating in
a room with negative pressure, the flue products can be
pulled back down the vent pipe and into the room. This
reverse flow of the flue gas may result in incomplete
combustion and the formation of carbon monoxide gas.
This raw gas or toxic fumes might then be distributed
throughout the house by the furnace duct system.
Return air can be brought in through the bottom or either
side of the furnace (return air brought into either side of
furnace allowed in upflow applications only). If a furnace
with bottom return air is installed on a platform, make an
airtight seal between the bottom of the furnace and the
platform to ensure that the unit operates properly and
safely. Use fiberglass sealing strips, caulking, or equivalent
sealing method between the plenum and the furnace
cabinet to ensure a tight seal. If a filter is installed, size the
return air duct to fit the filter frame.
Pipe & Fittings Specifications
All pipe, fittings, primer and solvent cement must conform
with American National Standard Institute and the American
Society for Testing and Materials (ANSI/ASTM) standards.
The solvent shall be free flowing and contain no lumps,
undissolved particles or any foreign matter that adversely
affects the joint strength or chemical resistance of the
cement. The cement shall show no gelation, stratification,
or separation that cannot be removed by stirring. Refer to
the Table 2 for approved piping and fitting materials.
Solvent cements for plastic pipe are flammable liquids
and should be kept away from all sources of ignition.
Do not use excessive amounts of solvent cement when
making joints. Good ventilation should be maintained to
reduce fire hazard and to minimize breathing of solvent
vapors. Avoid contact of cement with skin and eyes.
CAUTION
95G1UHEX exhaust and intake connections are made
of PVC. Use PVC primer and solvent cement when
using PVC vent pipe. When using ABS vent pipe, use
transitional solvent cement to make connections to the
PVC fittings in the unit.
IMPORTANT
Use PVC primer and solvent cement or ABS solvent
cement meeting ASTM specifications, refer to Table 2.
As an alternate, use all purpose cement, to bond ABS,
PVC, or CPVC pipe when using fittings and pipe made of
the same materials. Use transition solvent cement when
bonding ABS to either PVC or CPVC.
Содержание 95G1UH040BE12X
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