Use Of Furnace As Construction Heater - Lennox SIGNATURE SLP99UHV Installation Instructions Manual

in a public garage, hangar, or other building that has a
hazardous atmosphere, the furnace must be installed ac-
cording to recommended good practice requirements and
current National Fuel Gas Code or CSA B149 standard.
NOTE - Furnace must be adjusted to obtain a temperature
rise (100% percent capacity) within the range(s) specified
on the unit nameplate. Failure to do so may cause erratic
limit operation and may also result in premature heat ex-
changer failure. See ""Duct System" on page 10 for in-
stalling the optional discharge air sensor used to measure
temperature rise. Sensor is shipped with the unit.
This SLP99UHV 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 in-
stalled in parallel with, or on the upstream side of, cooling
units to avoid condensation in the heating compartment.
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. See FIGURE 3.
Heating Unit Installed Parallell to Air Handler Unit
(open during heating operation only)
(open during cooling operation only)
Heating Unit Installed Upstream of Cooling Unit
Evaporator
FIGURE 3
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
Dampers
Gas Unit
Air Handler Unit
Dampers
Gas Unit
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.
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.
Do not set thermostat below 60F (16C) in heating mode.
Setting below 60F (16C) reduces the number of heating
cycles. Damage to the unit may occur that is not covered
by the warranty.
The SLP99UHV furnace may be installed in alcoves, clos-
ets, attics, basements, garages, and utility rooms.
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

Units may be used for heating of buildings or structures
under construction, if the following conditions are met to
ensure proper operation:
DO NOT USE THE UNIT FOR CONSTRUCTION HEAT
UNLESS ALL OF THE FOLLOWING CRITERIA ARE
MET:
• Furnace must be in its final location. The vent system
must be permanently installed per these installation in-
structions.
• Furnace must be installed as a two pipe system and
one hundred percent (100%) outdoor air must be pro-
vided for combustion air requirements during construc-
tion.
• A room thermostat must control the furnace. The use
of fixed jumpers that will provide continuous heating is
prohibited.
• The input rate and temperature rise must be set per the
furnace rating plate.
• Supply and Return air ducts must be provided and
sealed to the furnace. Return air must be terminated
outside of the space where furnace is installed.
• Return air temperature range between 60°F (16°C) and
80°F (27°C) must be maintained.
• MERV 11 or greater air filters must be installed in the
system and must be regularly inspected and maintained
(e.g., regular static checks and replaced at end of life)
during construction.
• Blower and vestibule access panels must be in place on
the furnace at all times.
• The furnace heat exchanger, components, duct system,
and evaporator coils must be thoroughly cleaned follow-
ing final construction clean−up.
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CAUTION