Lennox International Inc Merit Series Gas Furnace installation instructions 1/2

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1-1/2 feet (.46 m) for each inch (25 mm) of common vent diameter.
10 − The vent pipe should be as short as possible with the least number of elbows and angles required to com- plete the job. Route the vent connector to the vent us- ing the shortest possible route.
11 − A vent connector shall be supported without any dips or sags and shall slope a minimum of 1/4 inch (6.4 mm) per linear foot (305 mm) of connector, back toward the appliance.
12 − Vent connectors shall be firmly attached to the furnace flue collar by self−drilling screws or other approved means, except vent connectors of listed type B vent material which shall be assembled according to the manufacturer’s instructions. Joints between sections of single wall connector piping shall be fastened by screws or other approved means.
13 − When the vent connector used for Category I ap- pliances must be located in or pass through a crawl- space, attic or other areas which may be cold, that por- tion of the vent connector shall be constructed of listed double-wall type B vent material or material having equivalent insulation qualities.
14 − All venting pipe passing through floors, walls, and ceil- ings must be installed with the listed clearance to com- bustible materials and be fire stopped according to lo- cal codes. In absence of local codes, refer to NFGC (Z223.1).
15 − No portion of the venting system can extend into, or pass through any circulation air duct or plenum.
INTERIOR TILE−LINED
MASONRY CHIMNEY
NOTE − the chimney must be properly sized per provided venting tables or lined with listed metal lining system.
PERMANENTLY SEALED FIREPLACE OPENING

Common Venting Using Tile−Lined Interior Masonry Chimney and Combined Vent Connector

MINIMUM LENGTH = AS SHORT AS PRACTICAL.

FOR MAXIMUM LENGTH SEE NOTE TO LEFT

NOTE− Refer to provided venting tables for installations.

OTHER

APPLIANCE

VENT

CONNECTOR

FURNACE

FIGURE 25

6 − The entire length of single wall metal vent connector shall be readily accessible for inspection, cleaning, and replacement.

7 − Single appliance venting configurations with zero lat- eral lengths (tables 3 and 4) are assumed to have no elbows in the vent system. For all other vent configura- tions, the vent system is assumed to have two 90° el- bows. For each additional 90° elbow or equivalent (for example two 45° elbows equal one 90° elbow) beyond two, the maximum capacity listed in the venting table should be reduced by 10% (0.90 x maximum listed ca- pacity).

8 − The common venting tables (5, 6, 7, and 8) were gen- erated using a maximum horizontal vent connector length of 1−1/2 feet (.46 m) for each inch (25 mm) of connector diameter as follows:

TABLE 2

Connector Diameter

Maximum Horizontal

inches (mm)

Connector Length feet (m)

 

 

 

 

3 (76)

4−1/2 (1.37)

 

 

4 (102)

6 (1.83)

 

 

5 (127)

7−1/2 (2.29)

 

 

6 (152)

9 (2.74)

 

 

7 (178)

10−1/2 (3.20)

9 − If the common vertical vent is offset, the maximum common vent capacity listed in the common venting tables should be reduced by 20%, the equivalent of two 90° elbows (0.80 x maximum common vent capacity). The horizontal length of the offset shall not exceed

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Contents Table of Contents Installation Instructions ML180UHTOP View Unit Dimensions − inches mmParts Arrangement Shipping and Packing List Safety InformationML180UH Gas Furnace General Use of Furnace as Construction HeaterCombustion, Dilution & Ventilation Air Equipment in Confined Space ALL AIR from Inside Equipment in Confined Space Setting Equipment Return Air Plenum End Bottom Horizontal Application Installation Clearances Top LeftRight Duct System FiltersUpflow Position VentingTop Vent Discharge Left Side Vent DischargeSide Vent Discharge Horizontal Left PositionHorizontal Right Position Vent Connection Upflow and Horizontal Position Common Venting Using Metal−Lined Masonry Chimney −1/2 18 − The common vent diameter must always be at least as Cated or common venting system, you must inspectFeet FAN + FAN FAN + NAT 112 175 169 278 Carbon Monoxide Poisoning Hazard − In some localities, codes may require the installation Ers or straps. Install a drip leg in vertical pipe runs toGas Piping Every 8 to 10 feet 2.44 to 3.01 m with suitable hangRight−Side Air Discharge Horizontal ApplicationLeft−Side Air Discharge Electrostatic Discharge ESD Interior MAKE−UP BOX InstallationElectrical Thermostat Designations ML180UH Schematic Wiring Diagram and Sequence of Operation Integrated Control Typical ML180UH Field Wiring DiagramUnit Start−Up For Your Safety Read Before LightingHigh Altitude Gas Pressure AdjustmentProper Combustion Manifold Pressure Settings at all Altitudes Other Unit AdjustmentsNo Jumper Heat FAN-OFF Time in Seconds750 453 900680 8851391 Single Side Return Air − Air volumes in bold require field860 653Electrical SHOCK, Fire Or Explosion Hazard ServiceHeat Exchanger Removal ML180UH BURNER, Combustion AIR Inducer Assembly−090, −110 −135 units −045 and −070 unitsPage Repair Parts List Planned ServiceDescription Integrated Control Diagnostic CodesNormal Heating Mode Abnormal Heating Mode Troubleshooting Heating Sequence of OperationHeating Sequence Normal Cooling Mode Abnormal Cooling Mode Troubleshooting Cooling Sequence of OperationContinuous Heat Speed FAN Sequence of Operation Troubleshooting Continuous Fan Sequence of Operation

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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