Sears 9MPD - Manual (Page 8)

Horizontal Furnace Installation
This furnace can be installed horizontally in an attic, basement,
crawl space, alcove, or suspended from a ceiling in a basement or
utility room . See Figure 4. Do not install furnace on its back or in
the reverse airflow positions as safety control operation will be ad­
versely affected.
If the furnace is to be suspended from the floor joists in a crawl
space or the rafters in an attic, it is necessary to use steel pipe
straps or an angle iron frame to rigidly attach the furnace to pre­
vent movement. These straps should be attached to the furnace
with sheet metal screws and to the rafters orjoists with bolts. The
preferred method is to use an angle iron frame bolted to the rafters
orjoists. (Take caution to allow door panels to be removed for
maintenance)
If the furnace is to be installed in a crawl space, consult local
codes. A suitable concrete pad or blocks are recommended for
crawl space installation on the ground.
NOTE:
6
" bottom clearance required for condensate trap.
Thirty (30) inches between the front of the furnace and adjacent
construction or other appliances MUST be maintained for service
clearance.
Keep all insulating materials clear from louvered door. Insulating
materials may be combustible.
The horizontal furnaces may be installed directly on combustible
wood flooring or supports as long as all required furnace clear­
ances are met. See Figure 4.
This furnace MUST NOT be installed directly on carpeting or tile
or other combustible material other than wood flooring or sup­
ports.
For horizontal installation over a finished living space. A field fab­
ricated auxiliary drain pan with drain pipe is required to prevent
damage by overflow due to blocked condensate drain.
3. Combustion & Ventilation Air
For Single Pipe Installation
A 1 A#ARIUII\IG
CARBON MONOXIDE POISONING HAZARD
Failure to provide adequate combustion and ventilation
air can result in death and/or personal injury.
Use methods described here to provide combustion and
ventilation air.
Furnaces require ventilation openings to provide sufficient air for
proper combustion and ventilation of flue gases. All duct or open­
ings for supplying combustion and ventilation air must comply
with National Fuel Gas Code, NFPA54/ANSI Z223.1, 2001 (or
current edition) and applicable provisions of local building codes.
This furnace can NOT be common vented or connected to any
type B, BW or L vent or vent connector, nor to any portion of a fac­
tory-built or masonry chimney. If this furnace is replacing a pre­
viously common-vented furnace, it may be necessary to resize
the existing vent and chimney to prevent oversizing problems for
the other remaining appliance(s). See
"Ventingand Combustion
Air Check"\n this section. This furnace MUST be vented to the
outside.
Air Openings and Connecting Ducts
1. Total input rating for all non direct vent gas appliances
MUST be considered when determining free area of open­
ings.
2. Connect ducts or openings directly to outside.
3. When screens are used to cover openings, they MUST be
no less than V
4
' mesh.
4. The minimum dimension of rectangular air ducts MUST
NOT be less than 3 ".
5. When sizing grille or louver, use the free area of opening. If
free area is NOT stamped or marked on grill or louver, as­
sume a
2 0
% free area for wood and 60% for metal.
Confined Space Installation
NOTE: A confined space is defined as an area with less than 50
cubic feet per 1,000 BTUH input rating for all gas appliances
installed in the area.
Requirements
1
. Provide confined space with sufficient air for proper com­
bustion and ventilation of fluegases using horizontal or ver­
tical ducts or openings.
2. Figure 5 illustrate how to provide combustion and ventila­
tion air. A minimum of two permanent openings, one inlet
and one outlet, are required.
3. One opening MUST be within 12 " of the floor and the se­
cond opening within
1 2
" of the ceiling.
a
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