Sterling TF - Manual (Page 14)

14
VENTING (continued) - HORIZONTALLY VENTED UNIT HEATERS
(CATEGORY III)
Horizontal venting arrangements are designed to be used
with single wall vent pipe. Horizontal venting arrangements
must terminate external to the building using UL 1738
listed vent. 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. See Figures 7, 8A and 9A for
special installation requirements regarding these venting
conditions.
Do not use Type B (double wall)
vent internally within the building on horizontally
vented power vented units! This can result in
death, serious injury or substantial property
damage.
If double wall venting is used, components which are UL
Listed and approved for Category III positive pressure
venting systems MUST be used.
A Breidert Type L, Fields Starkap, or equivalent vent cap
must be supplied by the customer for each power vented
unit. The vent pipe diameter MUST be as specified in
Table 1. All unit sizes are factory equipped with the
required fl ue size collar; attach in place (if not mounted
to outlet); refer to included vent collar instruction sheet
for additional requirements.
The vent terminal must be at least 12 inches (305mm)
from the exterior of the wall that it passes through to
prevent degradation of the building material by flue
gases.
Through the wall vent for these appliances shall NOT
terminate over public walkways, or over an area where
the condensate or vapor could create a nuisance or
hazard or could be detrimental to the operation of
regulators, relief valves, or other equipment.
The vent pipe equivalent length must not exceed 50 feet
(15.2m). Equivalent length is the total length of straight
sections PLUS 10 feet (3.05m) for each 90 elbow and
4 feet (1.22m) for each 45 elbow.
Maintain clearance between the vent pipe and combus-
tible materials according to vent pipe manufacturer’s
instructions.
The vent air system must be installed to prevent
collection of condensate. Pitch horizontal pipes
downward 1/4 inch per foot (21mm per meter) toward
the outlet for condensate drainage.
Horizontal portions of the venting systems shall be
supported at maximum intervals of 4 feet (1.2m) to
prevent sagging (in Canada, support at 3 feet (1m)
maximum intervals).
Insulate single wall vent pipe exposed to cold air or
running through unheated areas.
Each unit must have an individual vent pipe and vent
terminal! Each unit MUST NOT be connected to other
vent systems or to a chimney.
Vent Systems Termination Clearance Requirements
Structure/Object
Minimum Clearance for Termination Locations
USA CANADA
Door, window, or gravity vent inlet; combustion
air inlet for other appliances 9 inch for 10,000 to 50,000 BTU/Hr input;
12 inch for input exceeding 50,000 BTU/Hr. 9 inch (230mm) for 10,000 to 50,000 BTU/Hr input;
12 inch (305mm) for input exceeding 50,000 BTU/Hr.
Forced air inlet within 10 feet 3 feet above 6 feet (1.8m)
Adjoining Building or parapet 10 feet 10 feet (3.04m)
Adjacent public walkways 7 feet above grade 7 feet (2.1m) above grade
Electric, gas meters & regulators 4 feet horizontal
3 feet (0.9m) horizontally from meter/regulator
asembly. 6 feet (1.8m), any direction, from a gas
service regulator vent outlet
Above grade level* 1 foot 1 foot (0.3m)
*Minimum above maximum snow depth, or per local code, whichever is greater.
Table 5