Form I-RA/D 140/235 (Version A), Mfg No. 110318 Rev 4, Page 15
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Detailed
Requirements
for the Vent
System
(NOTE: Read all
before beginning
installation.)
•
Any portion of the
vent system that
passes through an
unheated space or a
concealed area such
as an “attic” must be
a factory-built vent
that is approved to
Standard UL 641.
See illustration . .
. . .
•
The heater may be
vented into a masonry
chimney that complies
with the BOCA Nation-
al Mechanical Code
for low-heat applianc-
es or other building
code requirements for
low-heat appliances.
• Pipe/Joints/Clearances:
Single-wall pipe must be a minimum
of 24 gauge galvanized steel for 8” or 9” diameter pipe and 22
gauge for 10” or 12” diameter pipe. Each joint must be secured
with three screws or rivets. If installing a factory-built vent, follow
the manufacturer’s instructions.
If the vent system passes through a combustible wall, material or
roof, for single wall pipe, maintain 18” (457mm) clearance or in-
stall a ventilated thimble that is not less than 12” (305mm) larger
than the diameter of the vent pipe. If installing factory-built vent,
follow the manufacturer’s instructions.
• Horizontal Length and Slope:
The horizontal portion of the
vent must comply with the maximum horizontal length shown in
the table below and have not more than two elbows. Horizontal
portions must be sloped upward 1/4” for each foot of pipe. If in-
stallation conditions require horizontal lengths in excess of those
permitted in the table, a draft inducer must be used.
Vent Pipe
Diameter
Model Size and Vertical
Length
Maximum Length of
Horizontal Pipe
8”
140 with 8 feet (2.4M) or
more of vertical pipe
Equal to or less than
the vertical height
8”
235 with 8 feet (2.4M) of
vertical pipe
4 feet (1.2M) or less
8”
235 with 10 feet (3M) or
more of vertical pipe
Equal to or less than
the vertical height
• Vent Size:
The vent system must be at least 8” in diameter.
