Lennox B050A3B, Installation/Servicing Instructions And Users Information Manual

Page: 10 / 36

Page 10 of 36 506307-01 Issue 1207
Air openings, intake and outlet pipes, return air grilles and
warm air registers must not be obstructed.
CAUTION
Filters :
Air filters must be used in every installation.
Minimum filter size and suggested filter material are
shown in Table 2. If different type filter is used, it must be an
equivalent high airflow capacity.
If the washable permanent filters are used with this unit they
should be cleaned periodically to prevent nuisance tripping
of the high limit switch and failure to provide adequate filter
media can cause equipment malfunction, uneven room
temperature and excessive fuel usage.
When installing the furnace with cooling equipment for
year round operation, the following recommendations must
be followed for series or parallel air flow:
1. In series flow applications, the coil is mounted after the
furnace in an enclosure in the supply air stream. The
furnace blower is used for both heating and cooling airflow.
2. In parallel flow installation, dampers must be provided to
direct air over the furnace heat exchanger when heat is
desired and over the cooling when cooling is desired.
IMPORTANT: The dampers should be adequate to
prevent cooled air from entering the furance, and if manually
operated, must be equipped with means to prevent operation
of either the cooling unit or furnace unless the damper is in
the full cool or full heat position.
Filter Size Selection
BTU
INPUT
FILTER
SIZE
50,000
75,000
100,000
125,000
13 X 23
13 X 23
16 1/2 X 26
20 X 23
Table 2
VENTING
Venting for the furnace must be to the outside and in
accordance with local codes or requirements of the local
utility. In the absence of local codes, venting must conform
to the applicable sections of the latest edition of the (U.S.)
National Fuel Gas Code ANSI Z223.1/NFPA 54. and/or CSA
B149.1 Natural Gas and Propane Installation Codes, and
the vent manufacturers instructions.
This furnace is CSA International apporved as a
Category I forced air appliance and can not be vented into
a vent system with any Category II, III or IV appliance. It
must be vented vertically, or nearly vertically, unless installed
with a listed mechancial venter in accordance with horizontal
venting instructions. It must not be connected to any portion
of a mechanical draft system operating under positive
pressure.
The vent system must be securely fastened to the
furnace flue collar with two (2) field supplied, corrosion
resitant, sheet metal screws located at least 120 degrees
apart and midway up the collar (see Figure 4).
VENT SYSTEM CONNECTION
Figure 4
The coil MUST be installed on the air discharge side of
the furnace. Under no circumstances should the air flow
be such that cooled, conditioned air can pass over the
furnace heat exchanger. This will cause condensation
in the heat exchanger and possible failure of the heat
exchanger that could lead to a fire hazard and/or
hazardous conditions that may lead to bodily harm. Heat
exchanger failure due to improper installation will not be
covered by warranty.
WARNING