5
Mortex Products, Inc. / FT. WORTH, TX 76106
G17 / G18 Installation Instructions
Printed 04/04
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Mortex Products, Inc. / FT. WORTH, TX 76106
G17 / G18 Installation Instructions
Printed 04/04
INSTALLATION INSTRUCTIONS
RETURN AIR
ALCOVE INSTALLATION
The furnace may be installed free standing or in an alcove
with a free flow of air back to the furnace. A minimum of
18” shall be provided at the front for return air and service
access.
CLOSET INSTALLATION - 6 in.
NOTE: If return air is through a side wall, there must be a
minimum of 6-in. clearance from side wall to furnace in
addition to 6-in. minimum clearance from inside of closet
door to front of furnace.
If a louvered door complying with the minimum air require-
ments is used, the front clearance may be reduced to 1”.
CLOSET INSTALLATIONS
Additional Requirements
Concerning under floor or ceiling return air systems, the
following items (1-10) must be adhered to:
1. The return-air opening into the closet, regardless of
location, is to be sized not less than specified on the
appliance rating plate.
2. If the return-air opening is located in the floor of the
closet (versus the vertical front or side wall), the
opening is to be provided with means to prevent its
inadvertent closure by a flat object placed over the
opening.
3. The cross-sectional area of the return duct system
(when located in the floor or ceiling of the
manufactured home) leading into the closet is to be not
less than that of the opening specified on the appli-
ances rating plate.
4. The total free area of openings in the floor or ceiling
registers serving the return-air duct system is to be not
less than 150% of the size opening specified on the
appliance rating plate. At least one such register is to
be located where the likelihood of its being covered by
carpeting, boxes, and other objects is minimized.
5. Materials located in the return duct system have a
flame spread classification of 200 or less.
6. Non-combustible pans having one-inch upturned
flanges are located beneath openings in the floor
return duct system.
7. Wiring materials located in the return duct system
conform to Article 300-22 (B&C) of the National
Electric Code, ANSI / NFPA-70.
8. Gas piping is not run in or through the return duct
system.
9. The negative pressure in the closet, as determined
by test with the air-circulating fan operating at high
heating speed and the closet door closed, is to be not
more negative than minus 0.05-inch water column.
10. For floor return systems, the manufactured home
manufacturer or installer shall affix a prominent
warning where it is easily read when the closet door is
open.
The marking shall read:
HAZARD OF ASPHYXIATION
DO NOT COVER OR RESTRICT FLOOR
OPENING, or equivalent
WARNING
RETURN AIR
ALCOVE
A minimum of 18” front clearance to a facing
wall or partition is needed for service access
and return air.
Provide a removable panel above the furnace
for access to roof jack and pipe connections on
top of the furnace.
CLOSET - 6” CLEARANCE
A minimum of 250 sq. in free open area return
opening is required to the closet. The return
opening may be anywhere on or above the
closet door. If the return is through a side wall,
and the opening is below the top of the furnace,
a minimum of 6-in. clearance from side wall to
furnace must be provided in addition to 6-in
minimum clearance from inside of closet door to
furnace.
If a 5T A/C will be installed, the return shall be
increased to 390-sq. in. open area.
SPECIAL-CLOSET, 1” CLEARANCE
For closet installations with less than 6-in.
clearance from inside of closet door to furnace,
a louvered closet door must be used with a min.
of 250 sq. in open area directly in line with the
furnace top louver panel as shown. A fully
louvered closet door may be used.
If a 5T A/C will be installed, the return shall be
increased to 390 sq. in open area directly in
line with the furnace louver panel.
ALCOVE INSTALLATION
CLOSET INSTALLATION
*SPECIAL - 1”- 6” CLOSET INSTALLATION
