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10) VENTING
A. BASIC FLUE VENTING — Venting must comply
with the latest edition of the National Fuel Gas Code
(ANSI Z223.1-latest edition) or the authority having
jurisdiction. Other venting references are in the
equipment volume of the ASHRAE Handbook.
Model
Heat Exchanger
Length ft
Maximum Vent Length ft.
(4" Diameter)
Maximum Fresh Air
Intake Length ft
(4" Diameter)
Vertical Venting
Sidewall Venting
RSG 25
15
100
75
50
RSG 35
15
100
75
50
RSG 45
15
100
75
50
SINGLE HEATER VENTING
(VERTICAL THROUGH THE ROOF)
Note: For residential applications, the heater must
not be connected to a separate chimney, but must
be installed using the venting system specified
below.
1. When venting the heater to outside of building
through a roof, use single-wall metal pipe. This
is to be constructed of galvanized sheet metal or
other approved noncombustible corrosion-resistant
material as allowed by state or local codes.
2. A vent passing through a combustible roof shall
extend through an approved clearance roof thimble.
Double-wall, Type B vent must be used for the
portion of the vent system which passes through
the combustible roof. An approved vent cap must
be attached to end of the flue.
3. The maximum equivalent length of vent pipe should
be carefully observed. A safety switch in the heater
is designed to shut the heater off before excessive
flue restriction causes bad combustion. Refer to the
Vent Sizing Table for maximum vent lengths and
vent pipe diameter.
• Minimum Equivalent Length = 5 ft. of pipe
• Maximum Equivalent Length = 75 ft. of pipe
Use the following correction factors to obtain the
equivalent length:
• Subtract 15 ft. if the run is horizontal.
• Subtract 10 ft. for an approved vent cap.
• Subtract 10 ft. for each elbow beyond 15 ft.
from the heater.
• Subtract 15 ft. for each elbow within 15 ft.
of the heater.
4. Joints between sections of piping shall be fastened
by sheet metal screws or other approved means
and should be sealed to prevent leakage of flue
gas into building. For Residential Installations:
The seams along the length of the piping and the
joints between sections of piping should be sealed
to prevent a potential leakage of flue gas into
building. Use 100% RTV Silicone Rubber Adhesive
sealant suitable for 500°F. For Commercial and
Industrial Installations: Use aluminum or Teflon
tape suitable for 550°F (3M Company tapes 433 or
363) or RTV silicone sealant.
5. Avoid locating elbows in the first 5' of vent pipe
whenever possible. Limit to (2) 90° elbows.
When vent pipe is in a horizontal run, it must
have 1/4 inch per foot rise.
6. All portions of the vent pipe shall be supported to
prevent from sagging (6' spacing is recommended).
STERLING “RSG” SERIES
INFRARED RADIANT TUBE HEATER
