ASX7-5-Installation Instructions

VENTING (continued)
4. Use UL 1738 listed single or double wall pipe for the
vent system. For installations in Canada, use corrosion
resistant and gas-tight, listed vent pipe conforming
with local building codes, or in the absence of local
building codes, with current CSA-B149.1, Installation
Codes for Natural Gas Burning Appliances and
Equipment or CSA-B149.2, Installation Codes for
Propane Gas Burning Appliances and Equipment.
For residential installations in the United States, vent
pipe approved for Category III appliances must be
used between the appliance and the combustion air
inlet box.
Never use pipe other than 5 inch
diameter. Never use PVC, ABS or any other non-
metallic pipe for venting! To do so may result in
serious damage to the unit and or severe personal
injury or death!
5. Any run of single or double wall vent pipe passing
through an unheated space must be insulated with
an insulation suitable to 550° F.
6. The vent system must be installed to prevent
collection of condensate. Pitch horizontal pipes
downward 1/4 inch per foot (21mm per meter)
toward the vent cap to facilitate drainage. Vertical
vent pipes should be piped as depicted in Figure 7.
7. The equivalent length of the vent system must not be
less than 5 feet (1.5m) and must not exceed 30 feet
(9m). The equivalent length equals the total length
of straight pipe plus 5 feet (1.5m) for each 90° elbow
and 2.5 feet (0.76m) for each 45° elbow.
8. For horizontal vent systems longer than 5 feet (1.5m),
the system must be supported from overhead building
structures at 4 foot (1.2m) intervals in the U.S. and at
3 foot (0.91m) intervals in Canada.
9. The exhaust vent system must remain at a minimum
distance of 1 inch (25mm) from all combustible
materials. Any part of the vent system that passes
through a combustible material must be properly
insulated.
NOTICE: Increasing the clearance distances may
be necessary if there is a possibility of distortion or
discoloration of adjacent materials.
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