Allied 95G1UHEX Series Use and care manual

507762-01 Issue 1907 Page 1 of 46
Save these instructions for future reference
INSTALLATION INSTRUCTIONS
95G1UHEX
Warm Air Gas Furnace
Upow / Horizontal Left and Right Air Discharge
(P) 507762-01
*P507762-01*
Manufactured By
Allied Air Enterprises LLC
A Lennox International, Inc. Company
215 Metropolitan Drive
West Columbia, SC 29170
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.
As with any mechanical equipment, personal injury can
result from contact with sharp sheet metal edges. Be
careful when you handle this equipment.
CAUTION
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 HVAC installer (or
equivalent), service agency or the gas supplier.
WARNING
Table of Contents
Unit Dimensions ..........................................................2
95G1UHEX Gas Furnace ............................................3
Shipping and Packing List ...........................................3
General ........................................................................5
Combustion, Dilution & Ventilation Air .........................6
Installation - Setting Equipment ...................................9
Filters .........................................................................12
Duct System ..............................................................12
Pipe & Fittings Specications ....................................13
Joint Cementing Procedure .......................................14
Venting Practices .......................................................16
Vent Piping Guidelines ..............................................17
Condensate Piping ....................................................30
Gas Piping .................................................................34
Electrical ....................................................................37
Unit Start-Up ..............................................................40
Gas Pressure Adjustment ..........................................42
Proper Combustion....................................................42
High Altitude Information ...........................................42
Testing for Proper Venting and Sufcient Combustion Air
for Non-Direct Vent Applications ................................43
Other Unit Adjustments..............................................43
Service.......................................................................45
Repair Parts List ........................................................46

507762-01Issue 1907Page 2 of 46
WEIVEDISWEIVTNORF
TOP VIEW
EXHAUST AIR
OUTLET
SUPPLY AIR
OPENING
3-1/4
(83)
2OPTIONAL
SIDE RETURN
AIR FILTER KIT
(Either Side)
23−3/4
(603)
25
(635)
COMBUSTION
AIR INTAKE
1-7/8 (48)
1−1/2
(38)
9/16
(14)
23
(584)
GAS PIPING INLET
(Right Side Only)
Side Return
Air Opening
(Either Side)
1Bottom Return
Air Opening
ELECTRICAL
INLET
(Either Side)
27−3/4
(705)
19−7/16
(494)
23−1/2
(597)
6−1/2 (165)
(Either Side)
1−15/16 (49)
14
(356)
12−5/8 (321)
1
3−1/4
(83)
1-1/2 (38)
Front Panel
2 (51)
CONDENSATE
TRAP CONNECTION
(Either Side)
(19)
3/4
(19)
1Bottom Return
Air Opening
A
B9/16 (14)
C
3/4
33
(838)
16
(406)
14−3/4
(375)
2OPTIONAL
SIDE RETURN
AIR FILTER KIT
(Either Side)
5/8
(16)
6-9/16 (167)
Left
9 (229)
Right
INTAKE AIR
Unit Dimensions
Model A B C
in. mm in. mm in. mm
95G1UH040BE12X
95G1UH060BE12X 17-1/2 446 16-3/8 416 16 406
95G1UH080CE16X
95G1UH100CE20X 21 553 19-7/8 505 19-1/2 495
1NOTE - 60C size units that require second stage air volumes
over 1800 cfm 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 lter.
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.

507762-01 Issue 1907 Page 3 of 46
95G1UHEX Gas Furnace
The 95G1UHEX Category IV gas furnace is shipped ready
for installation in the upow 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 upow applications with bottom return air.
The 95G1UHEX can be installed as either a Direct Vent
or a Non-Direct Vent gas central furnace.
The furnace is equipped for installation in natural gas
applications.
NOTE: In Direct Vent installations, combustion air is taken
from outdoors and ue gases are discharged outdoors. In
Non-Direct Vent installations, combustion air is taken from
indoors or ventilated attic or crawlspace and ue gases
are discharged outdoors. See Figure 1 and Figure 2 for
applications involving roof termination.
Shipping and Packing List
Package 1 of 1 contains
1 - Assembled 95G1UHEX unit
1 - Bag assembly containing the following:
1 - Snap bushing
1 - 1/2” diameter threaded street elbow
1 - Snap plug
1 - Wire tie
1 - Condensate trap
1 - Condensate trap cap
1 - Condensate trap clamp
1 - 2” diameter debris screen
1 - 3/4” Threaded street elbow
Check equipment for shipping damage. If you nd any
damage, immediately contact the last carrier.
The following items may also be ordered separately:
1 - Thermostat
1 - Return air base kit
1 - Horizontal suspension kit
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.
WARNING
DIRECT VENT INSTALLATION NON-DIRECT VENT
INSTALLATION
EXHAUST
OUTLET
COMBUSTION
AIR INTAKE OUTSIDE
OF HOUSE
COMBUSTION
AIR INTAKE
INSIDE
OF HOUSE
EXHAUST OUTLET
Figure 1.
NON-DIRECT VENT
INSTALLATION
NON-DIRECT VENT
INSTALLATION
COMBUSTION
AIR INTAKE INSIDE
VENTILATED
CRAWL SPACE
COMBUSTION
AIR INTAKE INSIDE
VENTILATED
ATTIC SPACE
EXHAUST
OUTLET
EXHAUST
OUTLET
Figure 2.
As with any mechanical equipment, personal injury can
result from contact with sharp sheet metal edges. Be
careful when you handle this equipment.
CAUTION
Use only the type of gas approved for use with this
furnace. Refer to unit nameplate. 95G1UHEX units are
CSA International certied to ANSI Z21.47 and CSA 2.3
standards.

507762-01Issue 1907Page 4 of 46
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 following address:
American National Standards Institute, Inc.
11 West 42nd Street
New York, 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.
Installation Locations
This furnace is CSA International certied for installation
clearances to combustible material as listed on the unit
nameplate and in the table in Figure 11. Accessibility
and service clearances must take precedence over re
protection clearances.
NOTE: For installation on combustible oors, the furnace
shall not be installed directly on carpeting, tile, or other
combustible material other than wood ooring.
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 oor.
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 specied on the unit nameplate.
Failure to do so may cause erratic limit operation and
premature heat exchanger failure.
This 95G1UHEX 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 coils (Figure 3),
it shall be installed in parallel with, or on the upstream
side of, cooling coils to avoid condensation in the heating
compartment. With a parallel ow arrangement, a damper
(or other means to control the ow 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.
Gas Unit
Heating Unit Installed Upstream of Cooling Coil
Gas Unit
Dampers
(open during heating operation only)
Dampers
(open during cooling operation only)
Heating Unit Installed Parallel to Air Handler Unit
Air Handler Unit
Cooling Coil
AIR FLOWAIR FLOW
AIR FLOW AIR FLOW
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.
The 95G1UHEX furnace may be installed in alcoves,
closets, attics, basements, garages, crawl spaces and
utility rooms in the upow or horizontal position.
This furnace design has not been CSA certied for
installation in mobile homes, recreational vehicles, or
outdoors.

507762-01 Issue 1907 Page 5 of 46
Use of Furnace as a Construction Heater
Units may be used for heating of buildings or structures
under construction, if the following conditions are met to
ensure proper operation.
DO NOT USE THE UNIT FOR CONSTRUCTION HEAT
UNLESS ALL OF THE FOLLOWING CRITERIA ARE
MET:
a. Furnace must be in its nal location. The vent system
must be permanently installed per these installation
instructions.
b. Furnace must be installed as a two pipe system
and one hundred percent (100%) outdoor air must
be provided for combustion air requirements during
construction.
c. A room thermostat must control the furnace. The use
of xed jumpers that will provide continuous heating is
prohibited.
d. The input rate and temperature rise must be set per
the furnace rating plate.
e. Supply and Return air ducts must be provided and
sealed to the furnace. Return air must be terminated
outside of the space where furnace is installed.
f. Return air temperature range between 60°F (16°C)
and 80°F (27°C) must be maintained.
g. MERV 11 or greater air lters must be installed in
the system and must be regularly inspected and
maintained (e.g., regular static checks and replaced at
end of life) during construction.
h. Blower and vestibule access panels must be in place
on the furnace at all times.
i. The furnace heat exchanger, components, duct
system, and evaporator coils must be thoroughly
cleaned following nal construction clean−up.
j. Air lters must be replaced upon construction
completion.
k. All furnace operating conditions (including ignition,
input rate, temperature rise and venting) must
be veried in accordance with these installation
instructions.
EQUIPMENT MAY EXPERIENCE PREMATURE
COMPONENT FAILURE AS A RESULT OF FAILURE TO
FOLLOW THE ABOVE INSTALLATION INSTRUCTIONS.
FAILURE TO FOLLOW THE ABOVE INSTALLATION
INSTRUCTIONS VOIDS THE MANUFACTURER’S
EQUIPMENT LIMITED WARRANTY. ALLIED AIR
DISCLAIMS ALL LIABILITY IN CONNECTION WITH
INSTALLER’S FAILURE TO FOLLOW THE ABOVE
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.
In addition to the requirements outlined previously, the
following general recommendations must be considered
when installing a 95G1UHEX furnace:
• Place the furnace as close to the center of the air
distribution system as possible. The furnace should
also be located close to the 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.
• Please consult the manufacturer of your evaporator
coil for their recommendations on distance required
between the heat exchanger and their drain pan.
Adequate space must be provided between the drain
pan and the furnace heat exchanger.
95G1UHEX unit should not be installed in areas
normally subject to freezing temperatures.
CAUTION
NOTWITHSTANDING THE FOREGOING, INSTALLER
IS RESPONSIBLE FOR CONFIRMING THAT THE USE
OF CONSTRUCTION HEAT IS CONSISTENT WITH
THE POLICIES AND CODES OF ALL REGULATING
ENTITIES. ALL SUCH POLICIES AND CODES MUST BE
ADHERED TO.

507762-01Issue 1907Page 6 of 46
Combustion, Dilution & Ventilation Air
If the 95G1UHEX 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 or ventilated attic or crawlspace and
ue gases are discharged outdoors.
In the past, there was no problem in bringing in sufcient
outdoor air for combustion. Inltration 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 replaces force additional
air that could be used for combustion out of the house.
Unless outside air is brought into the house for combustion,
negative pressure (outside pressure is greater than inside
pressure) will build to the point that a downdraft 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 95G1UHEX furnaces to ensure efcient
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
ofcial position of the ANSI on the referenced subject,
which is represented only by the standard in its entirety.
In Canada, refer to the CSA B149 installation codes.
Do not install the furnace in a corrosive or contaminated
atmosphere. Meet all combustion and ventilation air
requirements, as well as all local codes.
CAUTION
All gas-red appliances require air for the combustion
process. If sufcient combustion air is not available,
the furnace or other appliance will operate inefciently
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
replaces, 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 downdraft.
Insufcient 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.
The requirements for providing air for combustion and
ventilation depend largely on whether the furnace is
installed in an unconned or a conned space.
Unconned Space
An unconned 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 unconned, it might be necessary to bring in outdoor air
for combustion if the structure does not provide enough air
by inltration. 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.
Conned Space
A conned 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 denition includes furnace closets or small
equipment rooms. When the furnace is installed so that
supply ducts carry air circulated by the furnace to areas
Insufcient 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
• Cements and glues
• Antistatic fabric softeners for clothes dryers
• Masonry acid washing materials
WARNING

507762-01 Issue 1907 Page 7 of 46
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 conned 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 conned space
either from inside the building or from outside.
Air from Inside
If the conned space that houses the furnace adjoins a
space categorized as unconned, 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-red equipment in the conned
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.
OPENINGS
(To Adjacent
Unconfined
Space)
NOTE - Each opening shall have a free area of at least one square inch
per 1,000 Btu (645mm2per .29kW) per hour of the total input rating of
all equipment in the enclosure, but not less than 100 square inches
(64516mm2).
ROOF TERMINATED
EXHAUST PIPE
SIDE WALL
TERMINATED
EXHAUST PIPE
(ALTERNATE
LOCATION)
Figure 4. Equipment in Conned Space - All Air from
Inside
Air from Outside
If air from outside is brought in for combustion and
ventilation, the conned 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 Figure 5 and Figure 8.
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 9.
When ducts are used, they shall be of the same cross-
sectional 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 to 25 percent free area and metal louvers and
grilles will have 60 to 75 percent free area. Louvers and
grilles must be xed in the open position or interlocked
with the equipment so that they are opened automatically
during equipment operation.
OUTLET
AIR
INLET
AIR
VENTILATION
LOUVERS
(For unheated
crawl space)
FURNACE
ROOF TERMINATED
EXHAUST PIPE
VENTILATION LOUVERS
(Each end of attic)
SIDE WALL
TERMINATED
EXHAUST PIPE
(ALTERNATE
LOCATION)
NOTE-The inlet and outlet air openings shall each have a free
area of at least one square inch per 4,000 Btu (645mm2per
1.17kW) per hour of the total input rating of all equipment in
the enclosure.
Figure 5. Equipment in Conned Space - All Air from
Outlet
(Inlet Air from Crawl Space and Outlet Air to
Ventilated Attic)
Ventilation Louvers
Inlet Air
(Minimum 12 in.
(305mm) above
Attic Floor)
Roof Terminated
Exhaust Pipe
Furnace
*Intake Debris
Screen
(Provided)
* See Maximum Vent Lengths table
NOTE-The inlet and outlet air openings shall each have a free
area of at least one square inch per 4,000 Btu (645mm2per
1.17kW) per hour of the total input rating of all equipment in
the enclosure.
Figure 6. Equipment in Conned Space
(Inlet Air from Ventilated Attic and Outlet Air to
Outside)

507762-01Issue 1907Page 8 of 46
Roof Terminated
Exhaust Pipe
Furnace
Ventilation
Louvers
(Crawl Space)
*Intake Debris Screen Provided
Inlet Air
Minimum
12 in. (305mm)
above Crawl
Space Floor
Coupling or
3 in. to 2 in.
Transition
(Field Provided)
* See Maximum Vent Lengths table
NOTE-The inlet and outlet air openings shall each have a free
area of at least one square inch per 4,000 Btu (645mm2per
1.17kW) per hour of the total input rating of all equipment in
the enclosure.
Figure 7. Equipment in Conned Space
(Inlet Air from Ventilated Crawlspace and Outlet Air to
Outside)
OUTLET
AIR
VENTILATION LOUVERS
(Each end of attic)
INLET AIR
(Ends 12” above
bottom)
ROOF TERMINATED
EXHAUST PIPE
SIDE WALL
TERMINATED
EXHAUST PIPE
(ALTERNATE
LOCATION)
FURNACE
NOTE-The inlet and outlet air openings shall each have a free
area of at least one square inch per 4,000 Btu (645mm2per
1.17kW) per hour of the total input rating of all equipment in
the enclosure.
Figure 8. Equipment in Conned Space
(All Air through Ventilated Attic)
OUTLET AIR
INLET AIR
ROOF TERMINATED
EXHAUST PIPE
SIDE WALL
TERMINATED
EXHAUST PIPE
(ALTERNATE
LOCATION)
FURNACE
NOTE- Each air duct opening shall have a free area of at least
one square inch per 2,000 Btu (645mm2 per .59kW) 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 (645mm2 per 1.17kW) per hour of the total input
rating of all other equipment in the enclosure.
Figure 9. Equipment in Conned Space - All Air from
Outside
Shipping Bolt Removal
Units with 1/2 and 3/4 hp blower motor are equipped
with three exible legs and one rigid leg. The rigid leg
is equipped with a shipping bolt and a at white plastic
washer (rather than the rubber mounting grommet used
with a exible mounting leg). See Figure 10. 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.
RIGID LEG
(Remove shipping bolt
and washer)
Units with 1/2 or 3/4 HP Blower Motor
Figure 10. Shipping Bolt Removal

507762-01 Issue 1907 Page 9 of 46
Installation - Setting Equipment
Do not connect the return air duct 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.
WARNING
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.
WARNING
Upow Applications
The 95G1UHEX gas furnace can be installed as shipped
in the upow position. Refer to Figure 11 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. The unit may be
positioned from level to ½” toward the front. See Figure 12.
Allow for clearances to combustible materials as indicated
on the unit nameplate.
Improper installation of the furnace can result in
personal injury or death. Combustion and ue 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.
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 replace or stove, etc. Fire, explosion, carbon
monoxide poisoning, personal injury and/or property
damage could result.
WARNING
Top
Bottom (Floor)
Left Side Right Side
Top / Plenum 1 in. (25 mm)
* Front 1 in. (25 mm)
Back 1 in. (25 mm)
Sides 1 in. (25 mm)†
Vent 1 in. (25 mm)
Floor 0 in. ‡
* 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.
‡ For installations on a combustible oor, do not install the
furnace directly on carpeting, tile or other combustible
materials other than wood ooring.
Figure 11. Installation Clearances
Upow Applications
Return Air Guidelines
Return air can be brought in through the bottom or either
side of the furnace installed in an upow 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.
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.
Refer to Engineering Handbook for additional information.
95G1UHEX 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 eld-fabricated transition to
accommodate an optional IAQ accessory taller than 14.5”.
See Figure 14.

507762-01Issue 1907Page 10 of 46
UPFLOW APPLICATION
HORIZONTAL APPLICATION
FRONT VIEW SIDE VIEW
FRONT VIEW END VIEW
UNIT
FRONT
AIR FLOW
UNIT
FRONT
1/2”
max.
1/2”
max.
AIR FLOW
AIR FLOW
SIDE VIEW
UNIT
FRONT
Unit must be level side-to-side. Unit may be positioned from level to 1/2” toward the front to aid in draining.
Figure 12. Setting Equipment
FRONT VIEW
1Unit side return air
Opening
SIDE VIEW
3−1/4
(83)
1
23 (584)
Overall
(Maximum)
(584)
23
3/4
(19)
122−7/16
(570)
Overall
(Maximum)
SIDE RETURN
AIR OPENINGS
(Either Side)
5−5/8
(143)
1Minimum
11 (279)
2Maximum
14 (356)
(683)
26−7/8
7−1/4
(184)
FURNACE
FRONT
AIR FLOW
IF BASE
IS USED
WITHOUT
IAQ CABINET,
A SINGLE
RETURN AIR
PLENUM
MUST
COVER BOTH
UNIT AND
RETURN
AIR BASE
OPENINGS
INDOOR AIR
QUALITY
CABINET
AIR BASE
OPTIONAL
RETURN
17−1/2 (446) B Width (68W62)
21 (533) C Width (68W63)
24−1/2 (622) D Width (68W64)
NOTE- Optional side return air lter 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 of air and over (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 eld. 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.
Figure 13. Optional Return Air Base (Upow Applications Only)

507762-01 Issue 1907 Page 11 of 46
Return
Air
Plenum
Transition
20” x 25” x 1”
(508mm x 635mm x 25mm)
Air Filter
1−1/2”
Figure 14. Side Return Air
(with transition and lter)
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
panel. Once the bottom panel has been removed, reinstall
the bottom cap. See Figure 15.
Screw
Bottom Panel
Bottom Cap
Figure 15. Remove the Bottom Panel
Horizontal Applications
The 95G1UHEX furnace can be installed in horizontal
applications with either right- or left-hand air discharge.
Refer to Figure 17 for clearances in horizontal applications.
This furnace may be installed in either an attic or a
crawlspace. Either suspend the furnace from roof rafters or
oor joists, as shown in Figure 18, or install the furnace on a
platform, as shown in Figure 19. A horizontal suspension kit
(51W10) may be ordered from Allied Air or use equivalent.
Front Back
Do Not install the furnace on its front or back.
Figure 16.
Left-Hand Discharge
Top
Bottom (Floor)**
dnEthgiRdnEtfeL
AIR FLOW
dnEthgiRdnEtfeL
Right-Hand Discharge
Bottom (Floor)**
Air
Flow
Air
Flow
AIR FLOW
Top 1 in. (25 mm)
* Front 1 in. (25 mm)
Back 1 in. (25 mm)
Ends 1 in. (25 mm)
Vent 1 in. (25 mm)
Floor 1 in. (25 mm) ‡
* 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.
‡ For installations on a combustible oor, do not install the
furnace directly on carpeting, tile or other combustible
materials other than wood ooring.
Figure 17. Installation Clearances
Horizontal Applications
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.
Cooling coils and supply and return air plenums must be
supported separately.

507762-01Issue 1907Page 12 of 46
Bracket
(typical)
Metal
Strap
(typical)
Air
Flow
Internal Brace
(provided with
kit)
Figure 18. Horizontal Suspension Kit
NOTE: When the furnace is installed on a platform or with
the horizontal suspension kit in a crawlspace, 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 17.
2. Construct a raised wooden frame and cover frame
with a plywood sheet. If unit is installed above nished
space, fabricate an auxiliary drain pan to be installed
under unit. Set unit in drain pan as shown in Figure
19. 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.
*Gas connector may be
used for Canadian
by local authority
having jurisdiction.
*GAS CONNECTION
INTAKE PIPE
EXHAUST PIPE
RAISED
PLATFORM
SERVICE PLATFORM
installation if acceptable
Figure 19. Platform Installation
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 15.
Filters
This unit is not equipped with a lter or rack. A eld-provided
high velocity rated lter is required for the unit to operate
properly. Table 1 lists recommended lter sizes.
A lter must be in place whenever the unit is operating.
Furnace Cabinet
Width
Filter Size
Side Return Bottom Return
17-1/2” 16 x 25 x 1 (1) 16 x 25 x 1 (1)
21” 20 x 25 x 1 (1)
Table 1.
If a highefciency lter is being installed as part of this
system to ensure better indoor air quality, the lter must
be properly sized. Highefciency lters have a higher
static pressure drop than standard efciency glass/foam
lters. If the pressure drop is too great, system capacity
and performance may be reduced. The pressure drop
may also cause the limit to trip more frequently during
the winter and the indoor coil to freeze in the summer,
resulting in an increase in the number of service calls.
Before using any lter with this system, check the
specications provided by the lter manufacturer
against the data given in the appropriate Allied Air
Product Specications bulletin. Additional information
is provided in Service and Application Note ACC002
(August 2000).
IMPORTANT
Duct System
Use industry-approved standards to size and install the
supply and return air duct system. Figure 20 shows the
correct supply and return duct installation. Refer to ACCA
Manual D. This will result in a quiet and low-static system
that has uniform air distribution.
NOTE: This furnace is not certied 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.

507762-01 Issue 1907 Page 13 of 46
SUPPLY
AIR
SUPPLY
AIR
tinUlatnoziroHtinUwolfpU
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
replace) 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 ue products can be
pulled back down the vent pipe and into the room. This
reverse ow of the ue 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 upow 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 berglass sealing strips, caulking, or equivalent
sealing method between the plenum and the furnace
cabinet to ensure a tight seal. If a lter is installed, size the
return air duct to t the lter frame.
Pipe & Fittings Specications
All pipe, ttings, 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 owing 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, stratication,
or separation that cannot be removed by stirring. Refer to
the Table 2 for approved piping and tting materials.
Solvent cements for plastic pipe are ammable 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 re 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 ttings in the unit.
IMPORTANT
Use PVC primer and solvent cement or ABS solvent
cement meeting ASTM specications, refer to Table 2.
As an alternate, use all purpose cement, to bond ABS,
PVC, or CPVC pipe when using ttings and pipe made of
the same materials. Use transition solvent cement when
bonding ABS to either PVC or CPVC.

507762-01Issue 1907Page 14 of 46
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 tting and male end of pipe to
depth of tting socket.
Table 2. Piping and Fittings Specications
Schedule 40 PVC (Pipe) D1785
Schedule 40 PVC (Cellular Core Pipe) F891
Schedule 40 PVC (Fittings) D2466
Schedule 40 CPVC (Pipe) F441
Schedule 40 CPVC (Fittings) F438
SDR-21 PVC or SDR-26 PVC (Pipe) D2241
SDR-21 CPVC or SDR-26 CPVC (Pipe) F442
Schedule 40 ABS Cellular Core DWV
(Pipe) F628
Schedule 40 ABS (Pipe) D1527
Schedule 40 ABS (Fittings) D2468
ABS-DWV (Drain Waste & Vent)
(Pipe & Fittings) D2661
PVC-DWV (Drain Waste & Vent)
Pipe & Fittings) D2665
PRIMER & SOLVENT CEMENT ASTM
SPECIFICATION
PVC & CPVC Primer F656
PVC Solvent Cement D2564
CPVC Solvent Cement F493
ABS Solvent Cement D2235
PVC/CPVC/ABS All Purpose Cement For
Fittings & Pipe of the same material
D2564, D2235,
F493
ABS to PVC or CPVC Transition Solvent
Cement D3138
CANADA PIPE & FITTING & SOLVENT
CEMENT MARKING
PVC & CPVC Pipe and Fittings
ULCS636PVC & CPVC Solvent Cement
ABS to PVC or CPVC Transition Cement
POLYPROPYLENE VENTING SYSTEM ULC-S636
PolyPro® by Duravent
InnoFlue® by Centrotherm ULC-S636
ECCO Polypropylene VentTM ULC-S636
Canadian Applications Only - Pipe, ttings, primer and
solvent cement used to vent (exhaust) this appliance
must be certied to ULC S636 and supplied by a single
manufacturer as part of an approved vent (exhaust)
system. In addition, the rst three feet of vent pipe from the
furnace ue collar must be accessible for inspection.
NOTE: The intake coupling on the furnace is ABS material.
Use transitional solvent to make connections to PVC pipe.
NOTE: Exhaust coupling must be installed with provided
appliance adapter. See Figure 23.
Joint Cementing Procedure
All cementing of joints should be done according to the
specications outlined in ASTM D 2855.
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.
DANGER
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 tting socket and result in a
leaking joint.
NOTE: Check the inside of vent pipe thoroughly for
any obstruction that may alter furnace operation.
3. Clean and dry surfaces to be joined.
4. Test t joint and mark depth of tting on outside of pipe.
5. Uniformly apply a liberal coat of PVC primer for PVC
or use a clean dry cloth for ABS to clean inside socket
surface of tting and male end of pipe to depth of tting
socket.
NOTE: Time is critical at this stage. Do not allow
primer to dry before applying cement.
6. Promptly apply solvent cement to end of pipe and
inside socket surface of tting. Cement should be
applied lightly but uniformly to inside of socket. Take
care to keep excess cement out of socket. Apply
second coat to end of pipe.
7. Immediately after applying last coat of cement to pipe,
and while both inside socket surface and end of pipe
are wet with cement, forcefully insert end of pipe into
socket until it bottoms out. Turn PVC pipe 1/4 turn
during assembly (but not after pipe is fully inserted) to
distribute cement evenly. DO NOT turn ABS or cellular
core pipe.
NOTE: Assembly should be completed within 20
seconds after last application of cement. Hammer
blows should not be used when inserting pipe.
8. After assembly, wipe excess cement from pipe at end
of tting socket. A properly made joint will show a bead
around its entire perimeter. Any gaps may indicate an
improper assembly due to insufcient solvent.
9. Handle joints carefully until completely set.

507762-01 Issue 1907 Page 15 of 46
Table 3. Outdoor Termination Kits
Input
Size
Vent Pipe
Dia.
(in.)
STANDARD CONCENTRIC
Flush-
Mount Kit
Wall Kit Wall Ring
Kit
Field
Fabricated
1-1/2 in. 2 in. 3 in.
2 in. 3 in. 2 in.
51W11 (US)
51W12 (CA)
22G44 (US)
430G28 (CA)
44J40 (US)
481J20 (CA) 15F74 71M80 (US) 444W92 (CA)
69M29 (US)
444W92 (CA)
60L46 (US)
444W93 (CA)
040 23YES YES 1YES 1YES 5YES 2YES
33YES YES 1YES 1YES 5YES 2YES
060 23YES YES 1YES 1YES 5YES 2YES
33YES YES 1YES 1YES 5YES 2YES
080 23YES YES YES 5YES YES YES
33YES YES YES 5YES YES YES
100 23YES YES YES 5YES YES YES
33YES YES 5YES YES YES
NOTE - Standard Terminations do not include any vent pipe or elbows external to the structure. Any vent pipe or elbows external to the structure must
be included in total vent length calculations. See vent length tables.
* Kits must be properly installed according to kit instructions.
1 Requires eld-provided outdoor 1-1/2” exhaust accelerator.
2 Concentric kits 71M80 and 44W92 include 1-1/2” outdoor accelerator, when used with 040 and 060 input models.
3 Flush mount kits 51W11 and 51W12 includes 1-1/2 in. outdoor exhaust accelerator, required when used with 040, 060 and 080 input models.
4 Termination kits 30G28, 44W92, 44W93 and 81J20 are certied to ULC S636 for use in Canada only.
5 See Table 8 for vent accelerator requirements.

507762-01Issue 1907Page 16 of 46
4. Tighten both top and bottom bands to 40 in-lbs. See
Figure 23.
Route piping to outside of structure. Continue with
installation following instructions given in piping termination
section.
If the 95G1UHEX furnace replaces a furnace that was
commonly vented with another gas appliance, the size of
the existing vent pipe for that gas appliance must be
checked. Without the heat of the original furnace flue prod-
ucts, the existing vent pipe is probably oversized for the
single water heater or other appliance. The vent should be
checked for proper draw with the remaining appliance.
CHIMNEY
OR GAS
VENT
(Check sizing
for water
heater only)
FURNACE
WATER
HEATER
OPENINGS
(To Adjacent
Room)
REPLACING FURNACE THAT
WAS PART OF A COMMON
VENT SYSTEM
Figure 22.
Do not discharge exhaust into an existing stack or
stack that also serves another gas appliance. If vertical
discharge through an existing unused stack is required,
insert PVC pipe inside the stack until the end is even
with the top or outlet end of the metal stack.
CAUTION
The exhaust vent pipe operates under positive pressure
and must be completely sealed to prevent leakage of
combustion products into the living space.
CAUTION
Venting Practices
* See table 2 for allowable pipe.
NOTE - Isolate piping at the point where it exits the outside wall or
roof in order to prevent transmission of vibration to the structure.
SCHEDULE 40
PVC - 5'
all other pipe* - 3'
Wall edistuoedisni
24” maximum
3/4” minimum
Wall Thickness Guidelines
NOTE -
ward unit a minimum of 1/4” (6mm) drop for each 12” (305mm).
Figure 21. Piping Suspension Guidelines
1. In areas where piping penetrates joists or interior walls,
hole must be large enough to allow clearance on all
sides of pipe through center of hole using a hanger.
2. When furnace is installed in a residence where unit
is shut down for an extended period of time, such
as a vacation home, make provisions for draining
condensate collection trap and lines.
Exhaust Piping
See Figure 23, Figure 26 and Figure 27
The appliance adapter must be attached to the exhaust
coupling on the furnace top panel. Use the provided straps.
See steps below.
1. Remove caution tag from vent adapter
2. Fully insert vent adapter with both bands loosely
attached onto furnace exhaust coupling.
3. Insert PVC exhaust pipe through appliance adapter.
Ensure vent pipe is fully seated into exhaust coupling.

507762-01 Issue 1907 Page 17 of 46
Vent Piping Guidelines
NOTE: Allied Air has approved the use of DuraVent® and
Centrotherm manufactured vent pipe and terminations as
an option to PVC. When using the PolyPro® by DuraVent
or InnoFlue® by Centrotherm venting system the vent
pipe requirements stated in the unit installation instruction
– minimum & maximum vent lengths, termination
clearances, etc. – apply and must be followed. Follow
the instructions provided with PoyPro by DuraVent and
InnoFlue by Centrotherm venting system for assembly
or if requirements are more restrictive. The PolyPro by
Duravent and InnoFlue by Centrotherm venting system
must also follow the uninsulated and unconditioned space
criteria listed in Table 7.
The 95G1UHEX can be installed as either a Non-Direct
Vent or a Direct Vent gas central furnace.
NOTE: In Non-Direct Vent installations, combustion air is
taken from indoors and ue gases are discharged outdoors.
In Direct Vent installations, combustion air is taken from
outdoors and ue gases are discharged outdoors.
Intake and exhaust pipe sizing -- Size pipe according to
Table 4 and Table 5. Count all elbows inside and outside
the home. Table 4 lists the minimum vent pipe lengths
permitted. Table 5 lists the maximum pipe lengths permitted.
Regardless of the diameter of pipe used, the standard roof
and wall terminations described in section Exhaust Piping
Terminations should be used. Exhaust vent termination
pipe is sized to optimize the velocity of the exhaust gas as
it exits the termination. Refer to Table 8.
PVC Exhaust Pipe
Vent Adaptor
Furnace
Exhaust Coupling
Furnace Top Panel
Top Band
Bottom Band
Figure 23. Appliance Adaptor to Exhaust Coupling
In some applications which permit the use of several
different sizes of vent pipe, a combination vent pipe may
be used. Contact the Allied Air Application Department for
assistance in sizing vent pipe in these applications.
NOTE: The exhaust collar on all models is sized to
accommodate 2” Schedule 40 vent pipe. In horizontal
applications, any transition to exhaust pipe larger than 2”
must be made in vertical runs of the pipe. Therefore a 2”
elbow must be added before the pipe is transitioned to
any size larger than 2”. This elbow must be added to the
elbow count used to determine acceptable vent lengths.
Contact the Application Department for more information
concerning sizing of vent systems which include multiple
pipe sizes.
NOTE - Exhaust pipe MUST be glued to furnace exhaust fittings.
NOTE -
ward unit. A minimum of 1/4” (6mm) drop for each 12” (305mm)
of horizontal run is mandatory for drainage.
NOTE - Exhaust piping should be checked carefully to make
sure there are no sags or low spots.
Exhaust Pipe
Horizontal
Gas Furnace
12” Min.
12” Max.
Figure 24. Horizontal Installation Offset Requirements
95G1UHEX Model Min. Vent Length*
040, 060, 080, 100
15 ft. or
5 ft. plus 2 elbows or
10 ft. plus 1 elbow
*Any approved termination may be added to the minimum
length listed.
Table 4. Minimum Vent Pipe Lengths
Do not use screens or perforated metal in exhaust or
intake terminations. Doing so will cause freeze-ups and
may block the terminations.
IMPORTANT

507762-01Issue 1907Page 18 of 46
Use the following steps to correctly size vent pipe diameter.
040, 060,
080, 100 btuh
Standard or
Concentric?
See Table 3
Intake or
Exhaust?
2” or 3”
Furnace capacity?
1
Which termination?
2
Which needs most
elbows?
3
How many?
4
Desired pipe size?
5
What is the altitude?
6
Use Table 5 or 6 to find
max pipe length or
exhaust pipe length.
Includes all vent pipe
and elbows inside and
outside the house.
7
Figure 25.

507762-01 Issue 1907 Page 19 of 46
Table 5.
Maximum Allowable Intake or Exhaust Vent Length in Feet
Standard Termination at Elevation 0 - 4500 ft
Number of 90°
Elbows Used
2" Pipe 3" Pipe
Model Model
040 060 080 100 040 060 080 100
181 66 44 24 138 137 118 118
2 76 61 39 19 133 132 113 113
3 71 56 34 14 128 127 108 108
4 66 51 29
n/a
123 122 103 103
5 61 46 24 118 117 98 98
6 56 41 19 113 112 93 93
7 51 36 14 108 107 88 88
846 31
n/a
103 102 83 83
941 26 98 97 78 78
10 36 21 93 92 73 73
Concentric Termination at Elevation 0 - 4500 ft
Number of 90°
Elbows Used
2" Pipe 3" Pipe
Model Model
040 060 080 100 040 060 080 100
1 73 58 42 22 121 121 114 114
268 53 37 17 116 116 109 109
3 63 48 32 12 111 111 104 104
458 43 27
n/a
106 106 99 99
5 53 38 22 101 101 94 94
648 33 17 96 96 89 89
7 43 28 12 91 91 84 84
8 38 23
n/a
86 86 79 79
933 18 81 81 74 74
10 28 13 76 76 69 69
NOTE - Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Both Intake
and Exhaust must be same pipe size.
NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length
calculation.

507762-01Issue 1907Page 20 of 46
Table 6.
Maximum Allowable Exhaust Vent Lengths With Furnace Installed in a Closet or Basement Using Ventilated Attic or Crawl
Space For Intake Air in Feet
Standard Termination at Elevation 0 - 4500 ft
Number of 90°
Elbows Used
2" Pipe 3" Pipe
Model Model
040 060 080 100 040 060 080 100
1 71 56 34 14 118 117 98 98
2 66 51 29 9 113 112 93 93
3 61 46 24 4 108 107 88 88
4 56 41 19
n/a
103 102 83 83
5 51 36 14 98 97 78 78
6 46 31 9 93 92 73 73
7 41 26 4 88 87 68 68
836 21
n/a
83 82 63 63
931 16 78 77 58 58
10 26 11 73 72 53 53
NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length
calculation.
* When transitioning up in pipe size, use the shortest length of 2” PVC pipe possible.
TRANSITION
2” 2”
2”
3”
2”
2”
or
DO NOT transition
from smaller to larger
pipe in horizontal runs
of exhaust pipe.
EXHAUST
*2”
INTAKE
TRANSITION
3”
*2”
EXHAUST INTAKE
2”
Appliance
Adaptor
Appliance
Adaptor
Figure 26. Typical Exhaust and Intake Pipe Connections in Upow Direct Vent Applications