5894307-UIM-B-0920
Johnson Controls Ducted Systems
17
COMBUSTION AIR AND VENT PIPING ASSEMBLY
The final assembly procedure for the combustion air and vent piping is
as follows:
1. Cut piping to the correct length beginning at the furnace.
2. Deburr the piping inside and outside.
3. Chamfer (bevel) the outer edges of the piping.
4. Dry-fit the vent piping assembly from the furnace to the outside ter-
mination, checking for proper fit, support, and slope.
5. Dry-fit the combustion air piping assembly, checking for proper fit,
support, and slope on the following systems:
a. Sealed combustion air systems from the furnace to the outside
termination
b. Ventilated combustion air systems from the furnace to the attic or
crawl space termination
6. Disassemble the combustion air and vent piping and apply cement
primer and the cement per the manufacturer’s instructions. Primer
and cement must conform to ASTM D2564 for PVC or ASTM
D2235 for ABS piping.
7. All joints must provide a permanent airtight and watertight seal.
8. Install the combustion air and vent piping such that it has a 1/4 in./ft
(21 mm/m) grade so that condensate flows back toward the fur-
nace. Piping must be supported with pipe hangers to prevent sag-
ging.
9. Seal around the openings where the combustion air and/or vent
piping pass through the roof or sidewalls.
COMBUSTION AIR/VENTING
IMPORTANT:
Accessory concentric vent/intake termination kits
1CT0302 and 1CT0303, and for Canadian applications 1CT0302-636
and 1CT0303-636 are available and approved for use with these fur-
naces. Horizontal sidewall vent terminations kits 1HT0901 and
1HT0902 are also approved for use with these furnaces.
CAUTION
Solvent cements are flammable and must be used in well-ventilated
areas only. Keep them away from heat, sparks and open flames. Do
not breathe vapors and avoid contact with skin and eyes.
IMPORTANT:
The vent must be installed with the minimum required
clearances, and must comply with local codes and requirements.
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