Allied Air Enterprises A80UH2V - Manual (Page 12)

506471-01 Page 12 of 41 Issue 1034
Filters
This unit is not equipped with a filter or rack. A field provided
high velocity filter is required for the unit to operate properly.
Table 1 lists recommended filter sizes.
A filter must be in place any time the unit is operating.
Duct System
Use industry approved standards (such as those published
by Air Conditioning Contractors of America or American
Society of Heating, Refrigerating and Air Conditioning
Engineers) to size and install the supply and return air duct
system. This will result in a quiet and low static system that
has uniform air distribution.
NOTE: Do not operate the furnace in the heating mode
with an external static pressure that exceeds 0.8 inches w.c.
Higher external static pressures may cause erratic limit
operation.
Supply Air Plenum
If the furnace is installed without a cooling coil, a removable
access panel must be installed in the supply air duct. The
access panel should be large enough to permit inspection
(either by smoke or reflected light) of the heat exchanger
for leaks after the furnace is installed. The furnace access
panel must always be in place when the furnace is operating
and it must not allow leaks into the supply air duct system.
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 toxic gas
might then be distributed throughout the house by the furnace
duct system.
In upflow applications, the return air can be brought in through
the bottom or either side of the furnace. 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.
WARNING
The inner blower panel must be securely in place when
the blower and burners are operating. Gas fumes,
which could contain carbon monoxide, can be drawn
into living space resulting in personal injury or death.
WARNING
Improper installation of the furnace can result in personal
injury or death. Combustion and flue products must
never be allowed to enter the return air system or the
living space. Use screws and joint tape to seal the return
air system to the furnace.
In platform installations with bottom return air, the furnace
should be sealed airtight to the return air plenum. A
door must never be used as a portion of the return air
duct system. The base must provide a stable support
and an airtight seal to the furnace. Allow absolutely no
sagging, cracks, gaps, etc..
The return and supply air duct systems must never be
connected to or from other heating devices such as a
fireplace or stove, etc.. Fire, explosion, carbon
monoxide poisoning, personal injury and/or property
damage could result.
Figure 14
Horizontal Application
Unit installed on Platform
Table 1