Unit Dimensions − inches (mm)

1NOTE − 60C and 60D 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 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 Tables for additional information.

2Flue outlet may be horizontal but furnace must be vented vertically

3Optional external side return air filter kit cannot be used with the optional RAB Return Air Base.

3−1/8 (79)

D

SUPPLY AIR

OPENING

FLUE OUTLET

(Top)

3 OPTIONAL

 

 

 

 

23−3/4

 

 

 

 

 

 

EXTERNAL

 

 

 

 

 

(603)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SIDE RETURN

 

25

 

 

 

AIR FILTER KIT

 

 

 

(635)

 

 

 

 

 

 

 

(Either Side)

 

 

 

TOP VIEW

 

A

 

 

 

B

9/16 (14)

 

 

3OPTIONAL

 

 

EXTERNAL

 

 

SIDE RETURN

 

 

AIR FILTER KIT

 

 

(Either Side)

 

 

 

33

 

 

 

(838)

 

 

14−3/4

 

 

(375)

 

 

 

16

 

 

 

(406)

 

 

 

5/8

3/4

C

3/4

(16)

(19)

(19)

 

1Bottom Return

 

 

Air Opening

 

 

FRONT VIEW

3/4(19)

27−3/4

 

Front Panel

(705)

 

 

 

3−1/4 (83)

 

 

3 (76) Right

19−7/16

9/16

(14)

6−3/4 (171) Left

(494)

 

 

2 FLUE OUTLET

 

 

9−1/8 (232) Right

(Either Side)

 

 

ELECTRICAL INLET

 

8−5/8 (219) Left

 

(Either Side)

 

 

 

 

 

5−3/8 (137) Right

GAS PIPING INLET

 

1−9/16 (40) Left

(Either Side)

 

 

ELECTRICAL

23

 

1−1/2

INLET (Either Side)

 

(584)

 

(38)

 

1 Side Return

14

 

(Either Side)

Air Opening

(356)

 

 

(Either Side)

 

 

 

1−15/16 (49)

 

3−1/4

23−1/2

 

 

(83)

(597)

 

 

 

1Bottom Return

 

 

 

Air Opening

 

 

SIDE VIEW

ML180UH Model No.

 

A

 

B

 

C

 

D

in.

 

mm

in.

 

mm

in.

 

mm

in.

 

mm

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

045P24A

 

 

 

 

 

 

 

 

 

 

 

 

045P36A

14−1/2

 

368

13−3/8

 

340

13

 

330

4−3/4

 

121

070P24A

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

070P36A

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

090P36B

17−1/2

 

446

16−3/8

 

416

16

 

406

6−1/4

 

159

090P48B

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

110P48C

21

 

533

19−7/8

 

504

19−1/2

 

495

8

 

203

110P60C

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

135P60D

24−1/2

 

622

23−3/8

 

546

23

 

584

9−3/4

 

248

 

 

 

 

 

 

 

 

 

 

 

 

 

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Lennox International Inc Merit Series Gas Furnace installation instructions Unit Dimensions − inches mm, TOP View
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Merit Series Gas Furnace specifications

Lennox International Inc. is a leading name in the heating and cooling industry, and their Merit Series Gas Furnace embodies the commitment to quality and efficiency that the company is known for. The Merit Series is designed to provide reliable heating in a sustainable manner, making it an excellent choice for homeowners seeking comfort without excessive energy bills.

One of the standout features of the Merit Series Gas Furnace is its efficiency ratings. The units in this series typically boast Annual Fuel Utilization Efficiency (AFUE) ratings of up to 95%. This level of efficiency means that the furnace converts a significant portion of the fuel it uses into heat, ultimately lowering operating costs. Such energy-efficient performance is not only beneficial for the wallet but also promotes environmental sustainability.

The Merit Series also incorporates advanced technologies that enhance its operation. The inclusion of a multi-speed blower motor is a notable feature that provides thoughtful airflow management throughout the home. By adjusting the speed according to the heating needs, the furnace optimizes comfort levels while minimizing noise and energy consumption. Homeowners can enjoy a warm environment without the disruptive sounds often associated with traditional furnaces.

Moreover, the Merit Series comes equipped with durable construction materials designed to withstand the test of time. From the robust heat exchanger to the heavy-gauge cabinet, Lennox focuses on longevity and reliability. This ensures that homeowners can trust their furnace to operate effectively even in the harshest winter conditions.

Safety features are also integral to the design of the Merit Series Gas Furnace. With an integrated Flame Sensor and a built-in safety shut-off system, the furnace ensures that any irregularities in operation are promptly detected and addressed. Such measures provide peace of mind for families using the heating system throughout the cold months.

Installation and maintenance are further simplified with the Merit Series. Its design facilitates easier access for HVAC professionals, allowing for quicker installations and routine service, ensuring that homeowners spend less time and money on upkeep.

In conclusion, Lennox International Inc.'s Merit Series Gas Furnace combines efficiency, advanced technology, and robust construction, making it a top choice for families looking to enhance their home's heating system. With its energy-saving innovations and commitment to reliability, the Merit Series stands as an exemplary option in today’s market.
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