Venting - Space-Ray LTU Series Installation And Operation Instructions Manual

17.0)

VENTING

A. A. A. A. BASIC FLUE VENTING BASIC FLUE VENTING BASIC FLUE VENTING — Venting must comply with the latest edition of the National Fuel Gas Code (ANSI BASIC FLUE VENTING
Z223.1-latest edition) or the authority having jurisdiction. Other venting references are in the equipment
volume of the ASHRAE Handbook.
SINGLE HEATER VENTING SINGLE HEATER VENTING SINGLE HEATER VENTING SINGLE HEATER VENTING
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 vent pipe diameter.
Minimum Equivalent Length = 5 ft. of pipe
•
Maximum Equivalent Length = 100 ft. of 4" pipe for 40-175 Models and 6" pipe for 180-250 Models
•
Use the following correction factors to obtain the equivalent length:
Subtract 15 ft. if the run is horizontal. (maximum horizontal length for 4" pipe is 25 ft.)
•
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. Aluminum or Teflon tape suitable for 550ºF
(3M Company tapes 433 or 363) or silicone sealant is recommended.
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.
9. Single-wall metal pipe shall not originate in any unoccupied attic or concealed space and shall not pass
through any attic, inside wall or concealed space, or through any floor. For the installation of a single-wall
metal pipe through an exterior combustible wall, refer to latest edition of the National Fuel Gas Code or the
authority having jurisdiction.
10. A venting system shall terminate at least 3 ft. above any forced air inlet located within 10 ft.
Form #43155010
Sept 2011
(VERTICAL THROUGH THE ROOF) (VERTICAL THROUGH THE ROOF) (VERTICAL THROUGH THE ROOF) (VERTICAL THROUGH THE ROOF)
-39-
CARBON MONOXIDE HAZARD