Lennox EL180UHE User Manual

INSTALLATION

 2013 Lennox Industries Inc.

Dallas, Texas, USA

UPFLOW

AIR FLOW

INSTRUCTIONS EL180UHE

ELITE® SERIES GAS FURNACE UPFLOW / HORIZONTAL AIR DISCHARGE

507138-01 01/2013

Litho U.S.A.

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.

WARNING

Improper installation, adjustment, alteration, service or maintenance can cause property damage, person al injury or loss of life. Installation and service must be performed by a licensed professional installer (or equivalent), service agency or the gas supplier.

AIR FLOWAIR FLOW

HORIZONTAL LEFT HORIZONTAL RIGHT

Table of Contents

Unit Dimensions 2................................

EL180UHE Gas Furnace 3.........................

Shipping and Packing List 3........................

Safety Information 3...............................

Use of Furnace as a Construction Heater 4...........

General 4........................................

Combustion, Dilution & Ventilation Air 5..............

Setting Equipment 8...............................

Filters 11..........................................

Duct System 11....................................

Venting 12........................................

CAUTION

As with any mechanical equipment, personal injury can result from contact with sharp sheet metal edges. Be careful when you handle this equipment.

Gas Piping 20.....................................

Electrical 22.......................................

Integrated Control 25...............................

Unit Start-Up 26...................................

Gas Pressure Adjustment 27........................

High Altitude 27....................................

Proper Combustion 27..............................

Other Unit Adjustments 28..........................

Service 29........................................

Repair Parts List 30................................

Start Up Check List 31..............................

01/13

*2P0113*

Page 1

507138-01

*P507138-01*

Unit Dimensions - inches (mm)

1/2

NOTE − 60C and 60D size units that require air volumes over 1800 cfm (850 L/s) 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) cleanable air filter. Required to maintain proper air velocity.

2. Single side return air with optional Return Air Base

3. Bottom return air.

4. Return air from both sides.

5. Bottom and one side return air.

See Blower Performance TTables for additional information.

Flue outlet may be horizontal but furnace must be vented vertically

Optional External Side Return Air Filter Kit is not for use with the optional Return Air Base.

A B

9/16 (14)

OPTIONAL

EXTERNAL

SIDE RETURN

AIR FILTER KIT

(Either Side)

(838)

FLUE OUTLET

(Top)

OPTIONAL

EXTERNAL

SIDE RETURN

AIR FILTER KIT

(Either Side)

1−1/2 (38)

Front Panel

3 (76) Right 7 (178) Left

9−1/8 (232) Right

8−5/8 (219) Left

5−3/8 (137) Right

2−3/4 (70) Left

3−1/8 (79)

TOP VIEW

3−1/4 (83)

FLUE OUTLET

(Either Side)

GAS PIPING INLET

(Either Side)

ELECTRICAL INLET

(Either Side)

SUPPL Y AIR

OPENING

23−3/4

(603)

(635)

27−3/4

(705)

19−7/16

(494)

3/4

(19)

EL180UHE Model No.

045(X)E36A

070(X)E36B 090(X)E48B

090E60C 110(X)E60C

135E60D

(584)

Side Return Air Opening (Either Side)

23−1/2

(597)

Bottom Return

Air Opening

AIR FLOW

Bottom Return

Air Opening

3/4

(19)

14−3/4

(375)

(16)

(406)

5/8

3−1/4

(83)

FRONT VIEW SIDE VIEW

A B C D

in. mm in. mm in. mm in. mm

14-1/2 368 13-3/8 340 13 330 4-3/4 121

17-1/2 446 16-3/8 416 16 406 6-1/4 159

21 533 19-7/8 504 19-1/2 495 8 203

24-1/2 622 23-3/8 546 23 584 9-3/4 248

(356)

1−15/16 (49)

1−

Page 2

EL180UHE Gas Furnace

The EL180UHE unit is shipped ready for installation in the upflow or horizontal right position (for horizontal left posi tion the combustion air pressure switch must be moved) fueled by natural gas. A conversion kit (ordered separate ly) is required for use in LP/Propane gas applications. The furnace is shipped with the bottom panel in place. The bot tom panel must be removed if the unit is to be installed in a horizontal application. The panel may also be removed in upflow applications.

Shipping and Packing List

Package 1 of 1 contains

1 - Assembled EL180UHE unit 1 - Bag assembly containing the following:

2 - Screws 1 - Snap bushing 1 - Snap plug 1 - Wire tie 1 - Vent warning label 1 - Owner's manual and warranty card

The following items may be ordered separately: 1 - Thermostat 1 - Suspension kit (for horizontal installations) 1 - LP/Propane changeover kit 1 - Return air base 1 - High altitude kit 1 - Side filter kit

Check equipment for shipping damage. If you find any damage, immediately contact the last carrier.

Safety Information

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.

WARNING

CAUTION

As with any mechanical equipment, personal injury can result from contact with sharp sheet metal edges. Be careful when you handle this equipment.

Certifications

EL180UHE units are CSA International certified to ANSI Z21.47.

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). The National Fuel Gas Code is available from the following address:

American National Standards Institute, Inc. 11 West 42nd Street New York, NY 10036

Clearances

Adequate clearance must be made around the air open ings into the vestibule area. In order to ensure proper unit operation, combustion and ventilation air supply must be provided according to the current National Fuel Gas Code.

Vent installations must be consistent with the National Fuel Gas Code venting tables (in this instruction) and applicable provisions of local building codes.

This furnace is CSA International certified for installation clearances to combustible material as listed on the unit nameplate and in the tables in figures 7 and 11. 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.

Installed Locations

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 haz ardous atmosphere, the furnace must be installed accord ing to recommended good practice requirements and cur rent National Fuel Gas Code.

Temperature Rise

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 may result in premature heat exchanger failure.

This EL180UHE furnace must be installed so that its elec trical components are protected from water.

Page 3

Installed in Combination with a Cooling Coil

When this furnace is used with cooling units, it shall be installed in parallel with, or on the upstream side of, cooling units to avoid condensation in the heating compartment. See figure 1. With a parallel flow arrangement, a damper (or other means to control the flow of air) must adequately pre vent 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. See figure 1.

Heating Unit Installed Parallel to Cooling Coil

Dampers

(open during heating operation only)

Gas Unit

Cooling Coil

Dampers

(open during cooling operation only)

Heating Unit Installed Upstream of Cooling Coil

Gas Unit

Cooling Coil

FIGURE 1

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 Elec tric Code, ANSI/NFPA No. 70. The National Electric Code (ANSI/NFPA No. 70) is available from the following ad dress:

National Fire Protection Association 1 Battery March Park Quincy, MA 02269

NOTE - This furnace is designed for a minimum continu ous return air temperature of 60°F (16°C) or an intermit tent operation down to 55°F (13°C) dry bulb for cases where a night setback thermostat is used. Return air tem perature must not exceed 85°F (29°C) dry bulb.

The EL180UHE furnace may be installed in alcoves, clos ets, attics, basements, garages, crawl spaces and utility rooms in the upflow or horizontal position.

This furnace design has not been CSA International certified for installation in mobile homes, recreational vehicles, or outdoors.

Use of Furnace as Construction Heater

Lennox does not recommend the use of EL180UHE units as a construction heater during any phase of construction. Very low return air temperatures, harmful vapors and op eration of the unit with clogged or misplaced filters will dam age the unit.

EL180UHE units may be used for heating of buildings or structures under construction, if the following conditions are met:

D The vent system must be permanently installed per

these installation instructions.

D A room thermostat must control the furnace. The use of

fixed jumpers that will provide continuous heating is not allowed.

D The return air duct must be provided and sealed to the

furnace.

D Return air temperature range between 60°F (16°C) and

80°F (27°C) must be maintained.

D Air filters must be installed in the system and must be

maintained during construction.

D Air filters must be replaced upon construction comple

tion.

D The input rate and temperature rise must be set per the

furnace rating plate.

D One hundred percent (100%) outdoor air must be pro

vided for combustion air requirements during construc tion. Temporary ducting may supply outdoor air to the furnace. Do not connect duct directly to the furnace. Size the temporary duct following these instructions in section for Combustion, Dilution and Ventilation Air in a confined space with air from outside.

D The furnace heat exchanger, components, duct system,

air filters and evaporator coils must be thoroughly cleaned following final construction clean-up.

D All furnace operating conditions (including ignition, in

put 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.

In addition to the requirements outlined previously, the fol lowing general recommendations must be considered when installing a EL180UHE furnace:

 Place the furnace as close to the center of the air dis

tribution system as possible. The furnace should also be located close to the chimney or vent termination point.

Page 4

 Do not install the furnace where drafts might blow direct

ly into it. This could cause improper combustion and un safe operation.

 Do not block the furnace combustion air openings 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 insu

lated space, keep insulation away from the furnace.

NOTE - The Commonwealth of Massachusetts stipu lates these additional requirements:

D Gas furnaces shall be installed by a licensed plumb

er or fitter only.

D The gas cock must be “T handle” type.

D When a furnace is installed in an attic, the passage

way to and service area surrounding the equipment shall be floored.

WARNING

The State of California has determined that this prod uct may contain or produce a chemical or chemicals, in very low doses, which may cause serious illness or death. It may also cause cancer, birth defects or reproductive harm.

CAUTION

Do not install the furnace in a corrosive or contami nated atmosphere. Meet all combustion and ventila tion air requirements, as well as all local codes.

CAUTION

Insufficient combustion air can cause headaches, nausea, dizziness or asphyxiation. It will also cause excess water in the heat exchanger resulting in rust ing 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 combus tion 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

Combustion, Dilution & Ventilation Air

In the past, there was no problem in bringing in sufficient out door 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 combus tion. 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 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 liv ing space creating a potentially dangerous situation.

In the absence of local codes concerning air for combus tion and ventilation, use the guidelines and procedures in this section to install EL180UHE furnaces to ensure effi cient and safe operation. You must consider combustion air needs and requirements for exhaust vents. A portion of this information has been reprinted with permission from the National Fuel Gas Code (ANSI‐Z223.1). This reprinted ma terial is not the complete and official position of the ANSI on the referenced subject, which is represented only by the standard in its entirety.

All gas‐fired appliances require air for the combustion pro cess. If sufficient combustion air is not available, the fur nace or other appliances will operate inefficiently and un safely. 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, ex haust fans, or clothes dryers are used at the same time as the furnace, much more air is necessary to ensure proper combustion and to prevent a downdraft. 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 contami nants may include bleaches, adhesives, detergents, sol vents and other contaminants which can corrode furnace components.

The requirements for providing air for combustion and ven tilation 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 m bined input rating of all appliances installed in that space. This space also includes adjacent rooms which are not

) per 1,000 Btu (.29 kW) per hour of the com

Page 5

separated by a door. Though an area may appear to be un confined, it might be necessary to bring in outdoor air for combustion if the structure does not provide enough air by 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 cu bic feet (1.42 m

) 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 contain ing 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.

EQUIPMENT IN CONFINED

SPACE ALL AIR FROM INSIDE

CHIMNEY

OR GAS

VENT

WATER

FURNACE

HEATER

OPENINGS

(To Adjacent

Room)

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 mm

) 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 mm

). 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 2.

Air from Outside

If air from outside is brought in for combustion and ventila tion, the confined space must have two permanent open ings. 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 di rectly or by ducts with the outdoors or spaces (crawl or at tic) that freely communicate with the outdoors or indirectly through vertical ducts. Each opening shall have a minimum free area of 1 square inch (645 mm

) per 4,000 Btu (1.17

kW) per hour of total input rating of all equipment in the en closure. See figures 3 and 4. When communicating with the outdoors through horizontal ducts, each opening shall have a minimum free area of 1 square inch (645 mm

) per

2,000 Btu (.56 kW) per total input rating of all equipment in the enclosure. See figure 5.

When ducts are used, they shall be of the same cross-sec tional 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 cov ering is not known for calculating the size opening required, it may be assumed that wood louvers will have 20 to 25 per cent 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.

NOTE - Each opening shall have a free area of at least one square inch (645 mm ing of all equipment in the enclosure, but not less than 100 square inches (64516 mm

) per 1,000 Btu (.29 kW) per hour of the total input rat

FIGURE 2

Page 6

CHIMNEY OR

GAS VENT

FURNACE

(Inlet Air from Crawlspace and Outlet Air to Ventilated Attic)

VENTILATION LOUVERS

(Each end of attic)

EQUIPMENT IN CONFINED SPACE

ALL AIR FROM OUTSIDE

OUTLET

AIR

WATER

HEATER

CHIMNEY

OR GAS

VENT

FURNACE

VENTILATION

LOUVERS

(For unheated crawl space)

NOTE-The inlet and outlet air openings shall each have a free area of at least one square inch (645

) per 4,000 Btu (1.17 kW) per hour of the total input rating of all equipment in the enclosure.

INLET

AIR

FIGURE 3

EQUIPMENT IN CONFINED SPACE

ALL AIR FROM OUTSIDE

(All Air Through Ventilated Attic)

VENTILATION LOUVERS

(Each end of attic)

OUTLET

AIR

INLET AIR

(Ends 12 in.

above bottom)

WATER

HEATER

FURNACE

CHIMNEY

OR GAS

VENT

WATER

HEATER

EQUIPMENT IN

CONFINED SPACE

ALL AIR FROM

OUTSIDE

OUTLET AIR

INLET AIR

NOTE-The inlet and outlet air openings shall each have a free area of at least one square inch (645 mm

) per 4,000 Btu (1.17 kW) per hour of the total input rating of all equip ment in the enclosure.

FIGURE 4

Page 7

NOTE - Each air duct opening shall have a free area of at least one square inch (645 mm

) per 2,000 Btu (.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 communi cate directly with the outdoors, each opening shall have a free area of at least one square inch (645 mm

) per 4,000 Btu (1.17 kW) per

hour of the total input rating of all other equipment in the enclosure.

FIGURE 5

Setting Equipment

WARNING

Do not install the furnace on its front or its back. Do not connect the return air ducts to the back of the fur nace. Doing so will adversely affect the operation of the safety control devices, which could result in per sonal injury or death.

The EL180UHE gas furnace can be installed as shipped in either the upflow position or the horizontal position.

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, and installation and service clearances [24 inches (610 mm) at unit front]. The unit must be level.

NOTE - Units with 1/2 or 3/4 hp blower motors are equipped with three flexible legs and one rigid leg. See figure 6. 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). The bolt and washer

must be removed before the furnace is placed into op eration. After the bolt and washer have been removed, the

rigid leg will not touch the blower housing.

Units with 1/2 or 3/4 HP Blower Motor

RIGID LEG

remove shipping bolt and washe

FIGURE 6

Upflow Applications

Allow for clearances to combustible materials as indicated on the unit nameplate. Minimum clearances for closet or al cove installations are shown in figure 7.

Upflow Application Installation Clearances

Top

Left Side

Bottom

Type of Vent

Connector

Top 1 in. (25 mm) 1 in. (25 mm)

*Front 2-1/4 in. (57 mm)** 2-1/4 in. (57 mm)

Back 0 0

Sides 0† 0

Vent 6 in. (152 mm) 1 in. (25 mm)

Floor 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. ** 4-1/2” if single wall vent pipe is used. ‡For installation on a combustible floor, do not install the furnace directly on carpeting, tile or other combustible materials other than wood flooring. †Left side requires 3 inches if a single wall vent is used on 14-1/2 inch cabinets, or 2 inches if a single wall vent pipe is used on 17-1/2 inch cabinets.

Type C Type B1

Right Side

FIGURE 7

Page 8

Return Air -- Upflow Applications

l m)

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.

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.

Single Side Return Air

(with transition and filter)

20” X 25” X 1”

(508mm X 635mm X 25mm)

Cleanable Filter

NOTE -

cfm (850 L/s) must have one of the following:

1 - Single side return air with transition to accommodate 20

60C and 60D units that require air volumes over 1800

Return Air

Plenum

x 25 x 1 in. (508 x 635 x 25 mm) cleanable air filter. (Re quired to maintain proper air velocity.) See figure 8.

2 - Single side return air with optional return airbase. See fig

AIR FLOW

ure 9.

3 - Bottom return air.

Transition

4 - Return air from both sides.

5 - Bottom and one side return air.

FIGURE 8

Refer to Engineering Handbook for additional information.

Optional Return Air Base

(Upflow Applications Only -- For use with A, B, C and D cabinets)

FURNACE

FRONT

IF BASE IS USED

WITHOUT

INDOOR AIR

QUALITY

AIR FLOW

14−1/2 (368) A Width (65W75) 17−1/2 (446) B Width (50W98) 21 (533) C Width (50W99) 24−1/2 (622) D Width (51W00)

NOTE- Optional Side Return Air Filter Kits are not for use with Optional Return Air Base.

Both the unit return air opening and the base return air opening must be covered by a single plenum or IAQ cabinet.

CABINET

(PCO, Filter

Cabinet, etc.)

OPTIONAL RETURN AIR BASE

IAQ CABINET,

A SINGLE

RETURN AIR

PLENUM

MUST

COVER BOTH

UNIT AND

RETURN

AIR BASE

OPENINGS

3−1/4

(83)

7−1/4 (184)

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.

To minimize pressure drop, the largest opening height possible (up to 14 inches 356 mm) is preferred.

23 (584)

Overall

(Maximum)

Unit side return air

Opening

5−5/8 (143)

SIDE RETURN

AIR OPENINGS

(Either Side)

26−7/8

(683)

SIDE VIEW

(584)

Minimum

11 (279)

Maximum

14 (356)

(Maximu

22−7/1

(570)

Overal

3/4

(19)

FIGURE 9

Page 9

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 10.

Removing the Bottom Panel

Screw

Horizontal Applications

The EL180UHE furnace can be installed in horizontal ap plications. Order horizontal suspension kit (51W10) from Lennox, or use equivalent suspension method.

Allow for clearances to combustible materials as indicated on the unit nameplate. Minimum clearances for closet or al cove installations are shown in figure 11.

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 12, or install the furnace on a platform, as shown in figure 13.

Typical Horizontal Application

Unit Suspended in Attic or Crawlspace

Metal Strap

Bracket

3/16”

Air

Flow

Bottom Cap

Bottom Panel

FIGURE 10

Horizontal Application

Installation Clearances

Left End

Vent Connector

Type

Top 0 0

*Front 2-1/4 in. (57 mm)** 2-1/4 in. (57 mm)

Back 0 0

Ends 2 in. (51 mm) 2 in. (51 mm)

Vent 6 in. (152 mm) 1 in. (25 mm)

Floor 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. ** 4-1/2 in. if single wall vent pipe is used. ‡For installations on a combustible floor, do not install the furnace directly on carpeting, tile or other combustible materials other than wood flooring.

Top

Right

AIR FLOW

End

Bottom

Type C Type B1

FIGURE 12

NOTE - Heavy-gauge perforated 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 pip ing installation. Cooling coils and supply and return air

plenums must be supported separately. NOTE - When the furnace is installed on a platform in a

crawlspace, it must be elevated enough to avoid water damage and to allow the evaporator coil to drain.

Return Air -- Horizontal Applications

Return air must be brought in through the end of a furnace installed in a horizontal application. The furnace is equipped with a removable bottom panel to facilitate installation. See figure 10.

FIGURE 11

Page 10

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