Use Of Furnace As A Construction Heater; General - Lennox SIGNATURE SL280UHV Installation Instructions Manual

Temperature Rise
NOTE − Furnace must be adjusted to obtain a temperature
rise(high and low fire) within the range(s) specified on the unit
nameplate. Failure to do so may cause erratic limit operation
and may result in premature heat exchanger failure.
This SL280UHV furnace must be installed so that its elec-
trical components are protected from water.
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 Parallell to Air Handler Unit
Dampers
(open during heating operation only)
Air Handler Unit
Dampers
(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 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.
Gas Unit
Gas Unit
The SL280UHV furnace may be installed in alcoves, clos-
ets, attics, basements, garages, and utility rooms in the up-
flow or horizontal position.
This furnace is not designed for installation in mobile
homes, recreational vehicles, or outdoors.
Never use an open flame to test for gas leaks. Check all
connections using a commercially available soap solution
made specifically for leak detection.
Use of Furnace as Construction Heater
Lennox does not recommend the use of SL280UHV 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.
SL280UHV 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
D
these installation instructions.
A room thermostat must control the furnace. The use of
D
fixed jumpers that will provide continuous heating is not
allowed.
The return air duct must be provided and sealed to the
D
furnace.
Return air temperature range between 60°F (16°C) and
D
80°F (27°C) must be maintained.
Air filters must be installed in the system and must be
D
maintained during construction.
Air filters must be replaced upon construction comple-
D
tion.
D The input rate and temperature rise must be set per the
furnace rating plate.
One hundred percent (100%) outdoor air must be pro-
D
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.
The furnace heat exchanger, components, duct system,
D
air filters and evaporator coils must be thoroughly
cleaned following final construction clean−up.
All furnace operating conditions (including ignition, in-
D
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 SL280UHV furnace:
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