StyleCrest Installation Manual

6
• Means shall be provided that prevent inadvertent closure
of flat objects placed over the return air opening located
in the floor of the closet (versus the vertical front or side
wall).
• The total free area of openings in the floor or ceiling
registers serving the return air duct system must be at
least 235 in
2
. At least one register should be located
where it is not likely to be covered by carpeting, boxes
and other objects.
• Materials located in the return duct system must have a
flame spread classification of 200 or less. This includes
a closet door if the furnace is in a closet.
• Noncombustible pans having 1” upturned flanges are
located beneath openings in a floor duct system.
• Wiring materials located in the return duct system shall
conform to Articles 300-22 of the National Electrical
Code (ANSI C1/NFPA-70).
• Gas piping is not run in or through the return duct system.
CAUTION:
HAZARD OF ASPHYXIATION: Negative pressure
inside the closet, with closet door closed and
the furnace blower operating on high speed,
shall be no more negative than minus 0.05 inch
water column.
• Test the negative pressure in the closet with the air-
circulating fan operating at high speed and the closet
closed. The negative pressure is to be no more negative
than minus 0.05 inch water column.
• Air conditioning systems may require more duct register
and open louver area to obtain necessary airflow.
Supply Air
For proper air distribution, the supply duct system must be
designed so that the static pressure measured external
to the furnace does not exceed the listed static pressure
rating shown on the furnace rating plate.
Location, size, and number of registers should be selected
on the basis of best air distribution and floor plan of
the home. The supply air must be delivered to the
conditioned space by duct(s) secured to the furnace
casing, running full size and without interruption.
Three typical distribution systems are shown in Figure 5
FURNACE INSTALLATION
NOTE: These Installation procedures are suggested for
typical furnace installations. Since each installation is
different, the sequence of instructions may differ from
the actual installation. Only qualified HVAC technicians
should install this furnace.
The installer must be familiar with and comply with all
codes and regulations applicable to the installation of
these heating appliances and related equipment. In
the absence of local codes, the installation must be in
accordance with the current provisions of one or more of
the following standards.
• Federal Manufactured Home Constructions & Safety
Standard (H.U.D. Title 24, Part 3280.707[a][2])
• American National Standard (ANSI-119.2/NFPA-501C)
for all recreational vehicle installations.
• American National Standard (ANSI-Z223.1/NFPA-54)
and/or CAN/CSA B149 for all gas-fired furnace models.
• American National Standard (ANSI-Z95.1/NFPA-31)
and/or CSA B139 for all oil-fired furnace models.
• American National Standard (ANSI-C1/NFPA-70) and/or
CSA 22.1 Canadian Electric Code Part 1 for all electrical
field wiring.
• Units have been certified under standards UL 307A & B,
UL727-1999, ANSI Z21.47/CSA 2.3, and CSA B140.10.
General Information
• The furnace must be leveled at installation and attached
to a properly installed duct system. Do not use the
back of the furnace for return air. See page 5
for circulating requirements.
• The furnace must be installed so that all electrical
components are protected from water
• The dimensions of the room or alcove must be able to
accommodate the overall size of the furnace and the
installation clearances listed in Table 1, (page 5)
and Figure 1 (page 4)
• The furnace must be installed upstream from a
refrigeration system.
• MG1 series gas furnaces are certified for use on wood
flooring or supports, but must be installed on top of a
duct connector. This factory supplied accessory must
be installed in the floor cavity and attached to the supply
air duct before the furnace is installed.
Locating & Cutting Duct Openings
Floor cut-outs and fuel line holes must be carefully located
to avoid misalignment of the furnace, and vent piping.
To locate standard ducts see Figure 6 (page 7). For
round ducts, see Figure 7 (page 7).
1. Measure 10” from the rear wall or alcove and mark the
centerline of the cut-out on the floor.
2. Using the centerline as a starting point, draw the rest
of the duct cut-out to the dimensions shown in Figure
6 or Figure 7.
3. Cut out the floor opening 1/16” larger than the actual
cutout drawn. This will allow some clearance when
installing the duct connector.
4. Measure from the top of the floor down to the top of the
supply air duct to obtain the depth of the floor cavity.
NOTE: The depth of the floor cavity shown as “X” in
Figure 5. Typical Supply Duct System
A Single trunk duct
B
Dual trunk duct
w/crossover connector
C
Transition duct
w/branches