Combination of Indoor and Outdoor Air
1. Indoor openings shall compy with the Indoor Combustion
Air Method below and,
2. Outdoor openings shall be located as required in the Outdoor
Combustion Air Method mentioned previously and,
3. Outdoor openings shall be sized as follows:
a. Calculate the Ratio of all Indoor Space volume divided by
required volume for Indoor Combustion Air Method
below.
b. Outdoor opening size reduction Factor is 1 minus the
Ratio in a. above.
c. Minimum size of Outdoor openings shall be the size
required in Outdoor Combustion Air Method above
multiplied by reduction Factor in b. above. The minimum
dimension of air openings shall be not less than 3 in. (80
mm).
INSTALLATION
Step 1—Leveling Legs (If Desired)
When furnace is used in upflow position with side inlet(s), leveling
legs may be desired. (See Fig. 20.) Install field-supplied,
corrosion-resistant 5/16-in. machine bolts and nuts.
NOTE:
The maximum length of bolt should not exceed 1-1/2 in.
1. Position furnace on its back. Locate and drill a 5/16-in.
diameter hole in each bottom corner of furnace. (See Fig. 20.)
Holes in bottom closure panel may be used as guide locations.
2. For each hole, install nut on bolt and then install bolt and nut
in hole. (Install flat washer if desired.)
3. Install another nut on other side of furnace base. (Install flat
washer if desired.)
4. Adjust outside nut to provide desired height, and tighten inside
nut to secure arrangement.
NOTE:
Bottom closure must be used when leveling legs are used.
See Bottom Closure Panel section.
Step 2—Installation in Upflow and Downflow
Applications
NOTE:
For downflow applications, this furnace is approved for
use on combustible flooring when special base (available from
manufacturer) Part No. KGASB0201ALL is used. Special base is
not required when this furnace is installed on manufacturer’s Coil
Assembly Part No. CD5 or CK5, or Coil Box Part No. KCAKC is
used.
1. Determine application being installed from Table 3.
2. Construct hole in floor per dimensions specified in Table 3
and Fig. 21.
3. Construct plenum to dimensions specified in Table 3 and Fig.
21.
4. If downflow subbase (KGASB) is used, install as shown in
Fig. 22. If Coil Assembly Part No. CD5 or CK5 or Coil Box
Part No. KCAKC is used, install as shown in Fig. 23.
NOTE:
Remove furnace perforated, supply-air duct flanges when
they interfere with mating flanges on coil or downflow subbase. To
remove perforated, supply-air duct flanges, use wide duct pliers,
duct flange tool, or hand seamers to bend flange back and forth
until it breaks off. Be careful of sharp edges. (See Fig. 24.)
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent unit
operation or performance satisfaction.
Do not bend duct flanges inward as shown in Fig. 21. This
will affect airflow across heat exchangers and may cause limit
cycling or premature heat exchanger failure. Remove duct
flange completely or bend it inward a minimum of 210° as
shown in Fig. 24.
Step 3—Installation in Horizontal Applications
These furnaces can be installed horizontally in either horizontal
left or right discharge position. In a crawlspace, the furnace can
either be hung from floor joist or installed on suitable blocks or
pad. Furnace can be suspended from each corner by hanger bolts
and angle iron supports. (See Fig. 25.) Cut hanger bolts (4 each
3/8-in. all-thread rod) to desired length. Use 1 X 3/8-in. flat
washers, 3/8-in. lock washers, and 3/8-in. nuts on hanger rods as
shown in Fig. 25. Dimples are provided for hole locations. (See
Fig. 2.)
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent unit
operation or performance satisfaction.
The entire length of furnace MUST be supported when
furnace is used in a horizontal position to ensure proper
draining. When suspended, bottom brace supports sides and
center blower shelf. When unit is supported from the ground,
blocks or pad should support sides and center blower shelf
area.
Step 4—Air Ducts
GENERAL REQUIREMENTS
The duct system should be designed and sized according to
accepted national standards such as those published by: Air
Conditioning Contractors Association (ACCA), Sheet Metal and
Air Conditioning Contractors National Association (SMACNA) or
American Society of Heating, Refrigerating and Air Conditioning
Engineers (ASHRAE), or consult The Air Systems Design Guide-
lines reference tables available from your local distributor. The
duct system should be sized to handle the required system design
CFM at the design static pressure.
When a furnace is installed so that the supply ducts carry air
circulated by the furnace to areas outside the space containing the
Fig. 20—Leveling Legs
A89014
1
3
⁄
4
″
1
3
⁄
4
″
1
3
⁄
4
″
1
3
⁄
4
″
5
⁄
16
″
5
⁄
16
″
5
⁄
16
″
5
⁄
16
″
19
