International comfort products R9MSB0801716 Installation Instructions Manual page 22

INSTALLATION INSTRUCTIONS
4. Adjust outside nut to provide desired height, and tighten
inside nut to secure arrangement.
5. Reinstall bottom closure panel if removed.
Downflow Installation
NOTE: The furnace must be forward as shown in Figure 26 for
proper condensate drainage.
Supply Air Connections
NOTE: For downflow applications, this furnace is approved for
use on combustible flooring when any one of the following two
accessories are used:
S
Special Base, NAHA01101SB
S
Cased Coil Assembly − EAM4X, END4X, ENW4X,
EAD4X
1. Determine application being installed from Table 8.
2. Construct hole in floor per Table 8 and Figure 21.
3. Construct plenum to dimensions specified in Table 8 and
Figure 21.
4. Install special base coil assembly or coil box as shown in
Figure 21.
NOTE: It is recommended that the perforated supply−air duct
flanges be completely removed from furnace when installing
the furnace on a factory−supplied cased coil or coil box. To
remove the supply−air duct flange, use wide duct pliers or hand
seamers to bend flange back and forth until it breaks off. Be
careful of sharp edges. (See Figure 22.)
CAUTION
!
CUT HAZARD
Failure to follow this caution may result in personal
injury.
Sheet metal parts may have sharp edges or burrs.
Use care and wear appropriate protective clothing,
safety glasses and gloves when handling parts, and
servicing furnaces.
Connect supply−air duct to supply−air outlet on furnace. Bend
flange inward past 90_ with wide duct pliers (See Figure 22.)
The supply−air duct must be connected to ONLY the furnace
supply outlet or air conditioning coil casing (when used). When
installed on combustible material, supply−air duct must be
connected to ONLY the factory−approved accessory subbase,
or a factory−approved air conditioning coil casing. DO NOT cut
main furnace casing to attach supply side air duct, humidifier, or
other accessories. All supply−side accessories MUST be
connected to duct external to furnace casing.
Return Air Connections
WARNING
!
FIRE HAZARD
A failure to follow this warning could cause personal
injury, death and/or property damage.
Never connect return−air ducts to the back of the
furnace. Follow instructions below.
The return−air duct must be connected to return−air opening
(bottom inlet). DO NOT cut into casing sides (left or right).
Bypass humidifier connections should be made at ductwork or
coil casing sides exterior to furnace. (See Figure 28.)
22
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel installed
in bottom return−air opening. Remove and discard this panel
when bottom return air is used. To remove bottom closure
panel, see Figure 24 and Figure 25.
Horizontal Installation
NOTE:
Figure 26 for proper condensate drainage.
FIRE, EXPLOSION, AND CARBON MONOXIDE
POISONING HAZARD
Failure to follow this warning could result in personal
injury, death, or property damage.
Do not install the furnace on its back or hang
furnace with control compartment facing downward.
Safety control operation will be adversely affected.
Never connect return−air ducts to the back of the
furnace.
MINOR PROPERTY HAZARD
Failure to follow this caution may result in minor
property damage.
Local codes may require a drain pan under entire
furnace and condensate trap when a condensing
furnace is used in an attic application or over a
finished ceiling.
The furnace can be installed horizontally in an attic or
crawlspace on either the left−hand (LH) or right−hand (RH)
side. The furnace can be hung from floor joists, rafters or
trusses or installed on a non−combustible platform, blocks,
bricks or pad.
Platform Furnace Support
Construct working platform at location where all required
furnace clearances are met. (See Table 2 and Figure 30.) For
furnaces with 1−in. (25 mm) clearance requirement on side, set
furnace on non−combustible blocks, bricks or angle iron. For
crawlspace installations, if the furnace is not suspended from
the floor joists, the ground underneath furnace must be level
and the furnace set on blocks or bricks.
Suspended Furnace Support
The furnace must be supported under the entire length of the
furnace with threaded rod and angle iron. (See Figure 31.)
Secure angle iron to bottom of furnace as shown.
Roll−Out Protection
Provide a minimum 12−in. x 22−in. (305 x 559 mm) piece of
sheet metal for flame roll−out protection in front of burner area
for furnaces closer than 12−in. (305 mm) above the
combustible deck or suspended furnaces closer than 12−in.
(305 mm) to joists. The sheet metal MUST extend underneath
the furnace casing by 1−in. (25 mm) with the door removed.
The bottom closure panel on furnaces of widths 17−1/2−in.
(445 mm) and larger may be used for flame roll−out protection
when bottom of furnace is used for return air connection. See
Figure 30 for proper orientation of roll−out shield.
Supply Air Connections
For a furnace not equipped with a cooling coil, the outlet duct
shall be provided with a removable access panel. This opening
shall be accessible when the furnace is installed and shall be of
Specifications subject to change without notice.
Gas Furnace: R9MSB
The furnace must be pitched forward as shown in
WARNING
!
CAUTION
!
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