User Manual

Form 43471010
-24- Dec 2017
14.0) VENTING
This is a category lll appliance.
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.
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 ºF. For
Commercial and Industrial Installations: Use aluminum or Teflon tape suitable for 550ºF (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).
7. When the vent pipe passes through areas where the ambient temperature is likely to induce condensation
of the flue gases, the vent pipe should be insulated and a condensation drain should be provided.
8. Minimum clearance for single-wall flue pipe to combustible material shall be 6 inches. This may be reduced
when the combustible material is protected as specified in the National Fuel Gas Code or the authority
having jurisdiction.
Model
Heat
exchanger
length ft
Maximum vent length ft. (4” diameter)
Maximum Fresh air
intake length ft
(4” diameter)
Vertical Venting
Sidewall Venting
SIR 25
15
100
75
50
SIR 35
15
100
75
50
SIR 45
15
100
75
50