Use Of Furnace As A Construction Heaterl; General - Lennox MERIT ML180UHE045(X)E36A Installation Instructions Manual

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 man-
ually 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.
Heating Unit Installed Parallell to Air Handler Unit
(open during heating operation only)
Air Handler Unit
(open during cooling operation only)
Heating Unit Installed Upstream of Cooling Unit
Evaporator
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 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 ML180UHE 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,
Use of Furnace as Construction Heater
Lennox does not recommend the use of ML180UHE units
as a construction heater during any phase of construc-
tion. Very low return air temperatures, harmful vapors and
operation of the unit with clogged or misplaced filters will
damage the unit.
Dampers
Gas Unit
Dampers
Gas Unit
or outdoors.
ML180UHE units may be used for heating of buildings or
structures under construction, if the following conditions
are met:
• The vent system must be permanently installed per
these installation instructions.
• A room thermostat must control the furnace. The
use of fixed jumpers that will provide continuous
heating is not allowed.
• The return air duct must be provided and sealed to
the furnace.
• Return air temperature range between 60°F (16°C)
and 80°F (27°C) must be maintained.
• Air filters must be installed in the system and must
be maintained during construction.
• Air filters must be replaced upon construction com-
pletion.
• The input rate and temperature rise must be set per
the furnace rating plate.
• One hundred percent (100%) outdoor air must be
provided for combustion air requirements during
construction. Temporary ducting may supply out-
door air to the furnace. Do not connect duct directly
to the furnace. Size the temporary duct following
these instructions in section for Combustion, Dilu-
tion and Ventilation Air in a confined space with air
from outside.
• The furnace heat exchanger, components, duct
system, air filters and evaporator coils must be
thoroughly cleaned following final construction
clean-up.
• The refrigerant leak detection sensor must be in-
spected for dust/debris deposits. Please refer to the
evaporator coil and/or refrigerant detection sensor
kit instructions for additional information.
• All furnace operating conditions (including ignition,
input 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 author-
ities having jurisdiction before installation. In addition to
the requirements outlined previously, the following general
recommendations must be considered when installing a
ML180UHE 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 chimney or vent termi-
nation point.
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