Allied Air Enterprises 95G1UH, A93UH, A95UH, 92G1UH User Manual
INSTALLATION INSTRUCTIONS
A95UH, A93UH, 95G1UH & 92G1UH
Warm Air Gas Furnace
Upflow/Horizontal Left and Right Air Discharge
This manual must be left with the homeowner for future reference.
This is a safety alert symbol and should never be ignored. When you see this symbol on labels or in
manuals, be alert to the potential for personal injury or death.
CAUTION
As with any mechanical equipment, personal injury can
result from contact with sharp sheet metal edges. Be
careful when you handle this equipment.
WARNING
Improper installation, adjustment, alteration, service or
maintenance can cause property damage, personal injury
or loss of life. Installation and service must be performed
by a licensed professional installer (or equivalent), service
agency or the gas supplier.
TABLE OF CONTENTS
Unit Dimensions ............................................................ 2
A95/A93/95G1/92G1UH Parts Arrangement ................ 3
A95/A93/95G1/92G1UH Gas Furnace ......................... 4
Shipping and Packing List ............................................ 4
Safety Information ......................................................... 4
Use of Furnace as a Construction Heater .................... 5
General ......................................................................... 6
Combustion, Dilution, Ventilation Air ............................. 6
Setting Equipment ........................................................ 9
Filters .......................................................................... 13
Duct System ................................................................ 13
Pipe and Fittings Specifications .................................. 13
Joint Cementing Procedure ........................................ 15
Venting Practices ........................................................ 16
*506501-01*
Vent Piping Guidelines................................................ 17
Gas Piping .................................................................. 31
Electrical ..................................................................... 34
Unit Start Up................................................................ 37
Gas Pressure Measurement ....................................... 39
High Altitude Information ............................................. 39
Other Unit Adjustments ............................................... 41
Service ........................................................................ 42
Planned Service .......................................................... 44
Failure Codes .............................................................. 44
Repair Parts List ......................................................... 45
Start Up Checklist ....................................................... 46
Manufactured By
Allied Air Enterprises, Inc.
A Lennox International, Inc. Company
215 Metropolitan Drive
West Columbia, SC 29170
506501-01 Page 1 of 48Issue 1031
A95UH, A93UH, 95G1UH & 92G1UH Unit Dimensions - inches (mm)
1 NOTE - 20 C/D (5 Ton) size units installed in upflow
applications that require air volumes of 1800 cfm (850 L/s) or
greater must have one of the following:
1. Single side return air with transition, to accommodate
20 x 25 x 1 in. (508 x 635 x 25 mm) air filter.
2. Single side return air with optional RAB Return Air Base
3. Bottom return air.
4. Return air from both sides.
5. Bottom and one side return air.
2 Optional External Side Return Air Filter kit is not for use with
optional Return Air Base.
* Consider sizing requirements for optional IAQ equipment
before cutting side return opening.
FRONT VIEW SIDE VIEW
Model
A95UH/A93UH
95G1UH/92G1UH
045-08
045-12
070-08
070-12
090-12
090-16
110-16
110-20
135-20
in.
17-1/2
21
24-1/2
A
mm
446
533
622
16-3/8
19-7/8
23-3/8
B
in.
mm
416
505
594
in.
16
19-1/2
23
C
mm
406
495
584
in.
7-5/8
9-3/8
11-1/8
D
mm
194
238
283
506501-01Page 2 of 48 Issue 1031
EXPANDED VIEW
Figure 1
506501-01 Page 3 of 48Issue 1031
A95UH, A93UH, 95G1UH &92G1UH Gas Furnace
The A95UH/A93UH/95G1UH & 92G1UH Category IV gas
furnace is shipped ready for installation in the upflow or
horizontal position. The furnace is shipped with the bottom
panel in place. The bottom panel must be removed if the
unit is to be installed in horizontal or upflow applications with
bottom return air.
The A95UH/A93UH/95G1UH & 92G1UH can be installed
as either a Direct Vent or a Non-Direct Vent gas central
furnace
Safety Information
WARNING
Improper installation, adjustment, alteration, service or
maintenance can cause property damage, personal injury
or loss of life. Installation and service must be performed
by a licensed professional installer (or equivalent), service
agency or the gas supplier.
The furnace is equipped for installation in natural gas
applications. A conversion kit (ordered separately) is required
for use in propane/LP gas applications.
NOTE: In Direct Vent installations, combustion air is taken
from outdoors and flue gases are discharged outdoors. In
Non-Direct Vent installations, combustion air is taken from
indoors and flue gases are discharged outdoors. See Figure
2 for applications involving roof termination.
Figure 2
Shipping and Packing List
1 - Assembled Gas Furnace
1 - Bag assembly containing the following:
3 - Wire nuts
1 - Snap bushing
1 - Snap Plug
1 - Wire tie
1 - Condensate trap
1 - Condensate trap cap
1 - Condensate trap clamp
1 - 2” diameter debris screen
Check equipment for shipping damage. If you find any
damage, immediately contact the last carrier.
CAUTION
As with any mechanical equipment, personal injury can
result from contact with sharp sheet metal edges. Be
careful when you handle this equipment.
DANGER
DANGER OF EXPLOSION!
There are circumstances in which odorant used with LP/
Propane gas can lose its scent. In case of a leak, LP/
Propane gas will settle close to the floor and may be difficult
to smell. An LP/Propane leak detector should be installed
in all LP applications.
Use only the type of gas approved for use with this furnace.
Refer to unit nameplate.
A95UH/A93UH/95G1UH & 92G1UH units are CSA
International certified to ANSI Z21.47 and CSA 2.3 standards.
Building Codes
In the USA, installation of gas furnaces must conform with
local building codes. In the absence of local codes, units
must be installed according to the current National Fuel Gas
Code (ANSI Z223.1/NFPA 54). The National Fuel Gas Code
is available from the American National Standards
Institute, Inc., 11 West 42nd Street, New Your, NY 10036.
In Canada, installation must conform with current National
Standard of Canada CSA-B149 Natural Gas and Propane
Installation Codes, local plumbing or waste water codes and
other applicable local codes.
In order to ensure proper unit operation in non-direct vent
applications, combustion and ventilation air supply must be
provided according to the current National Fuel Gas Code
or CSA-B149 standard.
Please refer to specification sheets for available accessories.
506501-01Page 4 of 48 Issue 1031
Installed Locations
This furnace is CSA International certified for installation
clearances to combustible material as listed on the unit
nameplate and in the table in Figure 10. Accessibility and
service clearances must take precedence over fire protection
clearances.
NOTE: For installation on combustible floors, the furnace
shall not be installed directly on carpeting, tile, or other
combustible material other than wood flooring.
For installation in a residential garage, the furnace must be
installed so that the burner(s) and the ignition source are
located no less than 18 inches (457 mm) above the floor.
The furnace must be located or protected to avoid physical
damage by vehicles. When a furnace is installed in a public
garage, hangar, or other building that has a hazardous
atmosphere, the furnace must be installed according to
recommended good practice requirements and current
National Fuel Gas Code or CSA B149 standards.
Note: Furnace must be adjusted to obtain a temperature
rise within the range specified on the unit nameplate. Failure
to do so may cause erratic limit operation and premature
heat exchanger failure.
This furnace must be installed so that its electrical
components are protected from water.
Installed in Combination with a Cooling Coil
When this furnace is used with cooling units (Figure 3), it
shall be installed in parallel with, or on the upstream side of,
cooling units to avoid condensation in the heating
compartment. With a parallel flow arrangement, a damper
(or other means to control the flow of air) must adequately
prevent chilled air from entering the furnace. If the damper
is manually operated, it must be equipped to prevent
operation of either the heating or the cooling unit, unless it
is in the full HEAT or COOL setting.
When installed, this furnace must be electrically grounded
according to local codes. In addition, in the United States,
installation must conform with the current National Electric
Code, ANSI/NFPA No. 70. The National Electric Code (ANSI/
NFPA No. 70) is available from the following address:
National Fire Protection Association
1 Battery March Park
Quincy, MA 02269
In Canada, all electrical wiring and grounding for the unit
must be installed according to the current regulations of the
Canadian Electrical Code Part I (CSA Standard C22.1) and/
or local codes.
Heating Unit Installed Parallel to Air Handler Unit
Heating Unit Installed Upstream of Cooling Unit
Figure 3
NOTE: This furnace is designed for a minimum continuous
return air temperature of 60°F (16°C) or an intermittent
operation down to 55°F (13°C) dry bulb for cases where a
night setback thermostat is used. Return air temperature
must not exceed 85°F (29°C) dry bulb.
This furnace may be installed in alcoves, closets, attics,
basements, garages, and utility rooms in the upflow or
horizontal position.
This furnace design has not been CSA certified for installation
in mobile homes, recreational vehicles, or outdoors.
Use of Furnace as a Construction Heater
These units are not recommended for construction heater
during any phase of construction. Very low return air
temperature, harmful vapors and operation of the unit with
clogged or misplaced filters will damage the unit.
These units may be used for heating of buildings or structures
under construction, if the following conditions are met:
• The vent system must be permanently installed per these
installation instructions.
• A room thermostat must control the furnace. The use of
fixed jumpers that will provide continuous heating is not
allowed.
• The return air duct must be provided and sealed to the
furnace.
506501-01 Page 5 of 48Issue 1031
• Return air temperature range between 60°F (16°C) and
80°F (27°C) must be maintained.
• Air filters must be installed in the system and must be
maintained during construction.
WARNING
• Air filters must be replaced upon construction completion.
• The input rate and temperature rise must be set per the
furnace rating plate.
• One hundred percent (100%) outdoor air must be provided
for combustion air requirements during construction.
Temporary ducting may supply outdoor air to the furnace.
Do not connect duct directly to the furnace. Size the
temporary duct following the instructions in section for
Combustion, Dilution and Ventilation Air in a confined
space with air from outside.
• The furnace heat exchanger, components, duct system,
air filters and evaporator coils must be thoroughly
cleaned following final construction cleanup.
• All furnace operating conditions (including ignition, input
rate, temperature rise and venting) must be verified
according to these installation instructions.
General
These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
having jurisdiction before installation.
Product Contains Fiberglass Wool.
Disturbing the insulation in this product during
installation, maintenance, or repair will expose you to
fiberglass wool. Breathing this may cause lung cancer.
(Fiberglass wool is known to the State of California to
cause cancer.)
Fiberglass wool may also cause respiratory, skin, and
eye irritation.
To reduce exposure to this substance or for further
information, consult material safety data sheets available
from address shown below, or contact your supervisor.
Allied Air Enterprises, Inc.
215 Metropolitan Drive
West Columbia, SC 29170
Combustion, Dilution & Ventilation Air
If this unit is installed as a Non-Direct Vent Furnace,
follow the guidelines in this section.
NOTE: In Non-Direct Vent Installations, combustion air is
taken from indoors and flue gases are discharged outdoors.
In addition to the requirements outlined previously, the
following general recommendations must be considered
when installing one of these furnaces:
• Place the furnace as close to the center of the air
distribution system as possible. The furnace should also
be located close to the chimney or vent termination point.
• When the furnace is installed in non-direct vent
applications, do not install the furnace where drafts might
blow directly into it. This could cause improper
combustion and unsafe operation.
• When the furnace is installed in non-direct vent
applications, do not block the furnace combustion air
opening with clothing, boxes, doors, etc. Air is needed
for proper combustion and safe unit operation.
• When the furnace is installed in an attic or other insulated
space, keep insulation away from the furnace.
• When the furnace is installed in an unconditioned space,
consider provisions required to prevent freezing of
condensate drain system.
CAUTION
These units should not be installed in areas normally
subject to freezing temperatures.
WARNING
Insufficient combustion air can cause headaches,
nausea, dizziness or asphyxiation. It will also cause
excess water in the heat exchanger resulting in rusting
and premature heat exchanger failure. Excessive
exposure to contaminated combustion air will result in
safety and performance related problems. Avoid
exposure to the following substances in the combustion
air supply:
Permanent wave solutions
Chlorinated waxes and cleaners
Chlorine base 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
Antistatic fabric softeners for clothes dryers
Masonry acid washing materials
In the past, there was no problem in bringing in sufficient
outdoor air for combustion. Infiltration provided all the air
that was needed. In today’s homes, tight construction
practices make it necessary to bring in air from outside for
combustion. Take into account that exhaust fans, appliance
vents, chimneys, and fireplaces force additional air that could
be used for combustion out of the house. Unless outside
506501-01Page 6 of 48 Issue 1031
air is brought into the house for combustion, negative
pressure (outside pressure is greater than inside pressure)
will build to the point that a down draft can occur in the furnace
vent pipe or chimney. As a result, combustion gases enter
the living space creating a potentially dangerous situation.
In the absence of local codes concerning air for combustion
and ventilation, use the guidelines and procedures in this
section to install these furnaces to ensure efficient and safe
operation. You must consider combustion air needs and
requirements for exhaust vents and gas piping. A portion of
this information has been reprinted with permission from
the National Fuel Gas Code (ANSI-Z223.1/NFPA 54). This
reprinted material is not the complete and official position of
ANSI on the referenced subject, which is represented only
by the standard in its entirely.
In Canada, refer to the CSA B149 Installation codes.
CAUTION
Do not install the furnace in a corrosive or contaminated
atmosphere. Meet all combustion and ventilation air
requirements, as well as all local codes.
All gas-fired appliances require air for the combustion
process. If sufficient combustion air is not available, the
furnace or other appliance will operate inefficiently and
unsafely. Enough air must be provided to meet the needs
of all fuel-burning appliances and appliances such as exhaust
fans which force air out of the house. When fireplaces,
exhaust fans, or clothes dryers are used at the same time
as the furnace, much more air is required to ensure proper
combustion and to prevent a down draft. Insufficient air
causes incomplete combustion which can result in carbon
monoxide.
In addition to providing combustion air, fresh outdoor air
dilutes contaminants in the indoor air. These contaminants
may include bleaches, adhesives, detergents, solvents and
other contaminants which can corrode furnace components.
infiltration. If the furnace is located in a building of tight
construction with weather stripping and caulking around the
windows and doors, follow the procedures in the “Air from
Outside” section.
Confined Space
A confined space is an area with a volume less than 50
cubic feet (1.42 m³) per 1,000 Btu (.29 kW) per hour of the
combined input rating of all appliances installed in that space.
This definition includes furnace closets or small equipment
rooms.
When the furnace is installed so that supply ducts carry air
circulated by the furnace to areas outside the space
containing the furnace, the return air must be handled by
ducts which are sealed to the furnace casing and which
terminate outside the space containing the furnace. This is
especially important when the furnace is mounted on a
platform in a confined space such as a closet or small
equipment room. Even a small leak around the base of the
unit at the platform or at the return air duct connection can
cause a potentially dangerous negative pressure condition.
Air for combustion and ventilation can be brought into the
confined space either from inside the building or from outside.
Air from Inside
If the confined space that houses the furnace adjoins a space
categorized as unconfined, air can be brought in by providing
two permanent openings between the two spaces. Each
opening must have a minimum free area of 1 square inch
(645 mm²) per 1,000 Btu (.29 kW) per hour of total input
rating of all gas-fired equipment in the confined space. Each
opening must be at least 100 square inches (64516 mm²).
One opening shall be within 12 inches (305 mm) of the top
of the enclosure and one opening within 12 inches (305 mm)
of the bottom. See Figure 4.
Equipment in Confined Space - All Air From Inside
The requirements for providing air for combustion and
ventilation depend largely on whether the furnace is installed
in an unconfined or a confined space.
Unconfined Space
An unconfined space is an area such as a basement or
large equipment room with a volume greater than 50 cubic
feet (1.42 m³) per 1,000 Btu (.29 kW) per hour of the
combined input rating of all appliances installed in that space.
This space also includes adjacent rooms which are not
separated by a door. Though an area may appear to be
unconfined, it might be necessary to bring in outdoor air for
combustion if the structure does not provide enough air by
506501-01 Page 7 of 48Issue 1031
NOTE: Each opening shall have a free area of at least one square
inch per 1,000 Btu (645 mm² per .29 kW) per hour of the total input
rating of all equipment in the enclosure, but not less than 100 square
inches (64546 mm²).
Figure 4
Air from Outside
If air from outside is brought in for combustion and ventilation,
the confined space shall be provided with two permanent
openings. One opening shall be within 12” (305 mm) of the
top of the enclosure and one within 12” (305 mm) of the
bottom. These openings must communicate directly or by
ducts with the outdoors or spaces (crawl or attic) that freely
communicate with the outdoors or indirectly through vertical
ducts. Each opening shall have a minimum free area of 1
square inch per 4,000 Btu (645 mm² per .59 kW) per total
input rating of all equipment in the enclosure (See Figure 5).
EQUIPMENT IN CONFINED SPACE - ALL AIR FROM OUTSIDE
(Inlet Air from Crawl Space and Outlet Air to Ventilated Attic)
to 25 percent free area and metal louvers and grilles will
have 60 to 75 percent free area. Louvers and grilles must
be fixed in the open position or interlocked with the equipment
so that they are opened automatically during equipment
operation.
EQUIPMENT IN CONFINED SPACE - ALL AIR FROM OUTSIDE
(Inlet Air through Ventilated Attic)
NOTE: The inlet and outlet air openings shall each have a free area
of at least one square inch per 4,000 Btu (645 mm² per 1.17 kW) per
hour of the total input rating of all equipment in the enclosure.
NOTE: The inlet and outlet air openings shall each have a free area
of at least one square inch per 4,000 Btu (645 mm² per 1.17 kW) per
hour of the total input rating of all equipment in the enclosure.
Figure 5
If air from outside is brought in for combustion and ventilation,
the confined space must have two permanent openings. One
opening shall be within 12 inches (305 mm) of the top of the
enclosure and one opening within 12 inches (305 mm) of
the bottom. These openings must communicate directly or
by ducts with the outdoors or spaces (crawl or attic) that
freely communicate with the outdoors or indirectly through
vertical ducts. Each opening shall have a minimum free
area of 1 square inch (645 mm²) per 4,000 Btu (1.17 kW)
per hour of total input rating of all equipment in the enclosure.
See Figures 5 and 6. When communicating with the
outdoors through horizontal ducts, each opening shall have
a minimum free area of 1 square inch (645 mm²) per 2,000
Btu (.56 kW) per total input rating of all equipment in the
enclosure. See Figure 7.
When ducts are used, they shall be of the same crosssectional area as the free area of the openings to which
they connect. The minimum dimension of rectangular air
ducts shall be no less than 3 inches (75 mm). In calculating
free area, the blocking effect of louvers, grilles, or screens
must be considered. If the design and free area of protective
covering is not known for calculating the size opening
required, it may be assumed that wood louvers will have 20
Figure 6
EQUIPMENT IN CONFINED SPACE - ALL AIR FROM OUTSIDE
NOTE: Each air duct opening shall have a free area of at least one
square inch per 2,000 Btu (645 mm² per .59 kW) per hour of the
total input rating of all equipment in the enclosure. If the equipment
room is located against an outside wall and the air openings
communicate directly with the outdoors, each opening shall have a
free area of at least 1 square inch per 4,000 Btu (645 mm² per 1.17
kW) per hour of the total input rating of all other equipment in the
enclosure.
Figure 7
506501-01Page 8 of 48 Issue 1031
Shipping Bolt Removal
Units with 1/2 hp blower motor are equipped with three
flexible legs and one rigid leg. The rigid leg is equipped with
a shipping bolt and a flat white plastic washer (rather than
the rubber mounting grommet used with a flexible mounting
leg). See Figure 8. The bolt and washer must be removed
before the furnace is placed into operation. After the
bolt and washer have been removed, the rigid leg will not
touch the blower housing.
INSTALLATION
Setting Equipment
WARNING
Do not connect the return air ducts to the back of the
furnace. Doing so will adversely affect the operation of
the safety control devices, which could result in personal
injury or death.
Figure 8
Units with 1/2 HP
Blower Motor
Blower access panel must be securely in place when
blower and burners are operating. Gas fumes, which
could contain carbon monoxide, can be drawn into living
space resulting in personal injury or death.
The gas furnaces can be installed as shipped in the upflow
position. Refer to Figure 10 for clearances. Select a location
that allows for the required clearances that are listed on the
unit nameplate. Also consider gas supply connections,
electrical supply, vent connection, condensate trap and drain
connections, and installation and service clearances [24
inches (610 mm) at unit front]. The unit must be level from
side to side. Tilt the unit slightly (maximum 1/2 in. from
level) from back to front to aid in the draining of the heat
exchanger. See Figure 9.
Allow for clearances to combustible materials as indicated
on the unit nameplate.
SETTING EQUIPMENT
Unit must be level side-to-side in all applications.
WARNING
Upflow Applications
Tilt the unit slightly (Max. 1/2”) from back to front to aid in the draining of
the heat exchanger.
Figure 9
506501-01 Page 9 of 48Issue 1031
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 air in
the living space. Use sheet metal screws and joint tape
to seal return air system to furnace.
Return Air Guidlines
Return air can be brought in through the bottom or either
side of the furnace installed in an upflow application. If the
furnace is installed on a platform with bottom return, make
an airtight seal between the bottom of the furnace and the
platform to ensure that the furnace operates properly and
safely. The furnace is equipped with a removable bottom
panel to facilitate installation.
In platform installations with furnace return, 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.
For no reason should return and supply air duct systems
ever 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.
Installation Clearances
Markings are provided on both sides of the furnace cabinet
for installations that require side return air. Cut the furnace
cabinet at the maximum dimensions shown on page 2.
Furnace applications which include side return air and a
condensate trap installed on the same side of the cabinet
(trap can be installed remotely within 5 ft.) require either a
return air base or field-fabricated transition to accommodate
an optional IAQ accessory taller than 14.5”. See Figure 11.
Side Return Air
(with transition and filter)
Top/Plenum
* Front
Back
Sides
Vent
Floor
1 in. (25 mm)
0
0
0†
0
0‡
* Front clearance in alcove installation must be 24 in. (610 mm).
Maintain a minimum of 24 in. (610 mm) for front service access.
† Allow proper clearances to accommodate condensate trap and vent
pipe installation.
‡ For installations on a combustible floor, do not install the furnace
directly on carpeting, tile or other combustible materials other than
wood flooring.
Figure 10
Figure 11
506501-01Page 10 of 48 Issue 1031
Optional Return Air Base
(Upflow Applications Only)
FRONT VIEW
NOTE: Optional side return air filter kits are not for use with return air base.
1 Both the unit return air opening and the base return air opening must be covered by a single plenum or IAQ cabinet.
Minimum unit side return air opening dimensions for units requiring 1800 cfm or more of air (W x H): 23 x 11 in. (584 x 279 mm).
The opening can be cut as needed to accommodate plenum or IAQ cabinet while maintaining dimensions shown.
Side return air openings must be cut in the field. There are cutting guides stenciled on the cabinet for the side return air opening.
The size of the opening must not extend beyond the markings on the furnace cabinet.
2 To minimize pressure drop, the largest opening height possible (up to 14 inches) is preferred.
SIDE VIEW
Figure 12
panel. Once the bottom panel has been removed, reinstall
Removing the Bottom Panel
the bottom cap. See Figure 13.
Horizontal Applications
WARNING
Do not install the furnace on its front or its back. See
Figure 14.
Figure 13
Removing the Bottom Panel
Remove the two screws that secure the bottom cap to the
furnace. Pivot the bottom cap down to release the bottom
506501-01 Page 11 of 48Issue 1031
Figure 14
This furnace can be installed in horizontal applications with
either right or left hand air discharge.
Refer to Figure 15 for clearances in horizontal applications.
Horizontal Application
Installation Clearances
Right-Hand Discharge
Typical Horizontal Application
Figure 16
To p
* Front
Back
Ends
Vent
Floor
0
0
0
0
0
0‡
* Front clearance in alcove installation must be 24 in. (610 mm).
Maintain a minimum of 24 in. (610 mm) for front service access.
** An 8” service clearance must be maintained below the unit to provide
for servicing of the condensate trap unless the trap is mounted
remotely.
‡ For installations on a combustible floor, do not install the furnace
directly on carpeting, tile or other combustible materials other than
wood flooring.
Figure 15
Suspended Installation of Horizontal Unit
This furnace may be installed in either an attic or a crawl
space. Either suspend the furnace from roof rafters or floor
joists, as shown in Figure 16, or install the furnace on a
platform, as shown in Figure 17. A horizontal suspension kit
(51W10) may be ordered from your distributor or use
equivalent.
NOTE: Heavy-gauge sheet metal straps may be used to
suspend the unit from roof rafters or ceiling joists. When
straps are used to suspend the unit in this way, support
must be provided for both the ends. The straps must not
interfere with the plenum or exhaust piping installation.
NOTE: When the furnace is installed on a platform or with
the horizontal suspension kit in a crawl space, it must be
elevated enough to avoid water damage, accommodate drain
trap and to allow the evaporator coil to drain.
Platform Installation of Horizontal Unit
1. Select location for unit keeping in mind service and other
necessary clearances. See Figure 15.
2. Construct a raised wooden frame and cover frame with
a plywood sheet. If unit is installed above finished space,
fabricate an auxiliary drain pan to be installed under unit.
Set unit in drain pan as shown in Figure 17. Leave 8
inches for service clearance below unit for condensate
trap.
3. Provide a service platform in front of unit. When installing
the unit in a crawl space, a proper support platform may
be created using cement blocks.
4. Route auxiliary drain line so that water draining from
this outlet will be easily noticed by the homeowner.
5. If necessary, run the condensate line into a condensate
pump to meet drain line slope requirements. The pump
must be rated for use with condensing furnaces. Protect
the condensate discharge line from the pump to the
outside to avoid freezing.
6. Continue with exhaust, condensate and intake piping
installation according to instructions.
Cooling coils and supply and return air plenums must
be supported separately.
506501-01Page 12 of 48 Issue 1031
Figure 17
Return Air -- Horizontal Applications
Return air may be brought in only through the end of a furnace
installed in the horizontal position. The furnace is equipped
with a removable bottom panel to facilitate installation. See
Figure 13.
Duct System
Use industry approved standards 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: This furnace is not certified for operation in heating
mode (indoor blower operating at selected heating speed)
with an external static pressure which exceeds 0.5 inches
w.c. Operation at these conditions may result in improper
limit operation.
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
(by 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.
Filters
This unit is not equipped with a filter or rack. A field provided
filter is required for the unit to operate properly. Table 1 list
recommended filter sizes.
A filter must be in place whenever the is operating.
Table 1
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. 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
Table 2 for approved piping and fitting materials.
506501-01 Page 13 of 48Issue 1031
CAUTION
IMPORTANT
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.
PIPING AND FITTINGS SPECIFICATIONS
A95UH1D/A93UH1D/95G1UH & 92G1UH 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 fitting in the unit.
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.
Low temperature solvent cement is recommended during
cooler weather. Metal or plastic strapping may be used for
vent pipe hangers. Uniformly apply a liberal coat of PVC
primer for PVC or use a clean dry cloth for ABS to clean
inside socket surface of fitting and male end of pipe to depth
of fitting socket.
Canadian Applications Only
Pipe, fittings, primer and solvent cement used to vent
(exhaust) this appliance must be certified to ULC S636 and
supplied by a single manufacturer as part of an approved
vent (exhaust) system. When bonding the vent system to
the furnace, use ULC S636 approved One-Step Transition
Cement to bond the pipe to the flue collar, or to bond the 90°
elbow or reducing 90° elbow to the flue collar. In addition,
the first three feet of vent pipe from the furnace flue collar
must be accessible for inspection.
Table 2
506501-01Page 14 of 48 Issue 1031
OUTDOOR TERMINATION KITS USAGE
Table 3
Joint Cementing Procedure
All cementing of joints should be done according to the
specifications outlined in ASTM D 2855.
DANGER
DANGER OF EXPLOSION!
Fumes from PVC glue may ignite during system check.
Allow fumes to dissipate for at least 5 minutes before
placing unit into operation.
506501-01 Page 15 of 48Issue 1031
1. Measure and cut vent pipe to desired length.
2. Debur and chamfer end of pipe, removing any ridges or
rough edges. If end is not chamfered, edge of pipe
may remove cement from fitting socket and result in a
leaking joint.
3. Clean and dry surfaces to be joined.
4. Test fit joint and mark depth of fitting on outside of pipe.
5. Uniformly apply a liberal coat of PVCD primer for PVC
or use a clean dry cloth for ABS to clean inside socket
surface of fitting and male end of pipe to depth of fitting
socket.
NOTE: Time is critical at this stage. Do not allow primer to
dry before applying cement.
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