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
Installation Locations
This furnace is CSA International certified for installation clearances to combustible material as listed on the unit nameplate and in the table in figure 12. Accessibility and service clearances must take precedence over fire protec tion clearances.
NOTE - For installation on combustible floors, the furnace shall not be installed directly on carpeting, tile, or other combustible material other than wood flooring.
For installation in a residential garage, the furnace must be installed so that the burner(s) and the ignition source are located no less than 18 inches (457 mm) above the floor. The furnace must be located or protected to avoid physical damage by vehicles. When a furnace is installed in a public garage, hangar, or other building that has a hazardous at mosphere, the furnace must be installed according to rec ommended good practice requirements and current Na tional Fuel Gas Code or CSA B149 standards.
NOTE - Furnace must be adjusted to obtain a temperature rise within the range specified on the unit nameplate. Fail ure to do so may cause erratic limit operation and prema ture heat exchanger failure.
This ML193UH furnace must be installed so that its electri cal 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 compart ment. With a parallel flow arrangement, a damper (or other means to control the flow of air) must adequately prevent chilled air from entering the furnace. If the damper is manu ally 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 ad dress:
National Fire Protection Association
1 Battery March Park
Quincy, MA 02269
In Canada, all electrical wiring and grounding for the unit must be installed according to the current regulations of the Canadian Electrical Code Part I (CSA Standard C22.1) and/or local codes.
Heating Unit Installed Parallell to Air Handler Unit | ||
| Dampers |
|
| (open during heating operation only) | |
| Gas Unit |
|
AIR FLOW |
| AIR FLOW |
| Air Handler Unit |
|
| Dampers |
|
| (open during cooling operation only) | |
Heating Unit Installed Upstream of Cooling Coil | ||
AIR FLOW | Gas Unit | AIR FLOW |
| Cooling Coil |
|
FIGURE 3
NOTE - This furnace is designed for a minimum continuous return air temperature of 60°F (16°C) or an intermittent op eration 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 ML193UH 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 certified for installa tion in mobile homes, recreational vehicles, or outdoors.
Use of Furnace as Construction Heater
Lennox does not recommend the use of ML193UH 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.
ML193UH 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.
DA room thermostat must control the furnace. The use of fixed jumpers that will provide continuous heating is not allowed.
DThe return air duct must be provided and sealed to the furnace.
DReturn air temperature range between 60°F (16°C) and 80°F (27°C) must be maintained.
DAir filters must be installed in the system and must be maintained during construction.
Page 4
