650.75-N4U
035-14370-000
18
Unitary Products Group
PIPING ASSEMBLY
The final assembly procedure for the vent/combustion air pip-
ing is as follows:
1.
Cut piping to the proper length, beginning at the furnace.
2.
Deburr the piping inside and outside.
3.
Chamfer the outer edges of the piping.
4.
Dry-fit the entire vent/combustion air piping assembly.
5.
Disassemble the piping and apply cement primer and
cement per the cement manufacturer's instructions.
Primer and cement must conform to ASTM D2564 for
PVC, or ASTM D2235 for ABS piping.
6.
All joints must be made to provide a permanent, air-tight,
water-tight seal.
7.
Support the combustion air and vent piping such that it is
angled 1/4” per linear foot so that condensate will flow
back toward the furnace. Piping should be supported
with pipe hangers to prevent sagging. Maximum spacing
between hangers is five (5) feet, except SDR-PVC pip-
ing, where maximum spacing is three (3) feet.
8.
Seal around the openings where the combustion air and
vent piping pass through the roof of side wall.
FIGURE 19 : HORIZONTAL TERMINATION CON-
FIGURATION WITH HORIZONTAL
EXTENSION
FIGURE 20 : VERTICAL TERMINATION
FIGURE 21 : DOUBLE SIDEWALL TERMINATION
VENT
OVERHANG
COMBUSTION AIR
12" SEPARATION BETWEEN
BOTTOM OF COMBUSTION AIR
AND BOTTOM OF VENT
MAINTAIN 12" CLEARANCE ABOVE
HIGHEST ANTICIPATED SNOW LEVEL
OR GRADE, WHICHEVER IS GREATER
12" MINIMUM
90°
18" MAXIMUM
MAINTAIN 12" MINIMUM
CLEARANCE ABOVE HIGHEST
ANTICIPATED SNOW LEVEL.
MAXIMUM OF 24" ABOVE ROOF
COMBUSTION AIR
VENT
12" VERTICAL SEPARATION
BETWEEN COMBUSTION
AIR AND VENT
VENT
COMBUSTION AIR
2"
FIGURE 22 : DOUBLE ROOFTOP TERMINATION
Solvent cements are flammable and must be used
in well-ventilated areas only. Keep them away from
heat, sparks and open flames (including pilots). Do
not breathe vapors and avoid contact with skin and
eyes.
6"
