Use Of Furnace As A Construction Heaterl; General; Combustion, Dilution, Ventilation Air - Lennox SL280DFNV Installation Instructions Manual

GAS UNIT
Dampers
(open during heating
operation only)
FIGURE 2
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 SL280DFNV furnace may be installed in alcoves,
closets, attics, basements, garages, and utility rooms in
the downflow position.
This furnace design has not been CSA International
certified for installation in mobile homes, recreational
vehicles, or outdoors.
Use of Furnace as Construction Heater
Construction heat is not allowed with this furnace.
AIR HANDLER
Dampers
(open during cooling
operation only)
Page 5

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
following general recommendations must be considered
when installing a SL280DFNV 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.
• Do not install the furnace where drafts might blow
directly into it. This could cause improper combus-
tion and unsafe operation.
• Do not block the furnace combustion air openings
with clothing, boxes, doors, etc. Air is needed for
proper combustion and safe unit operation.
• When the furnace is installed in an attic or other
insulated space, keep insulation away from the fur-
nace.
Combustion, Dilution & Ventilation Air
In the past, there was no problem in bringing in sufficient
outdoor air for combustion. Infiltration provided all the air
that was needed. In today's homes, tight construction
practices make it necessary to bring in air from outside for
combustion. Take into account that exhaust fans, appli-
ance vents, chimneys, and fireplaces force additional air
that could be used for combustion out of the house. Un-
less outside air is brought into the house for combustion,
negative pressure (outside pressure is greater than inside
pressure) will build to the point that a downdraft can oc-
cur in the furnace vent pipe or chimney. As a result, com-
bustion gases enter the living space creating a potentially
dangerous situation.
In the absence of local codes concerning air for combus-
tion and ventilation, use the guidelines and procedures in
this section to install SL280DFNV furnaces to ensure ef-
ficient and safe operation. You must consider combustion
air needs and requirements for exhaust vents. A portion of
this information has been reprinted with permission from
the National Fuel Gas Code (ANSI Z223.1). This reprint-
ed material is not the complete and official position of the
ANSI on the referenced subject, which is represented only
by the standard in its entirety.
CAUTION
Do not install the furnace in a corrosive or
contaminated atmosphere. Meet all combustion
and ventilation air requirements, as well as all local
codes.