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A single-wall, metal vent pipe used as a vent connector in
residential or commercial applications, or as a vertical gas
vent in commercial applications, must have all seams and
joints sealed with pressure-sensitive aluminum tape or
silicone rubber sealant. The aluminum tape must have a
temperature rating of at least 400°F (204°C), i.e., 3M 433
or equivalent. Silicone rubber sealant must have a tem-
perature rating of 482°F (250°C), i.e., Dow Corning RTV-
736 or equivalent. All joints must be secured with at least
two corrosion-resistant screws. All joints must be checked
for gas tightness after installation.
VERTICAL VENTS USING METAL VENT PIPE -
COMMERCIAL AND RESIDENTIAL INSTALLATIONS
These compact unit heaters are listed as Category 1
appliances for vertical vent installations.
1 - These unit heaters are to be used with NFPA- or
ANSI-approved chimneys or U.L.-listed type B-1 gas
vents, or listed chimney lining systems for gas venting
where applicable, as well as the modifications and
limitations listed in figure 6. Seal single-wall, metal
pipe according to
General Recommendations and
Requirements
section.
2 - A single-wall metal pipe may be used as a vent
connector between the unit heater and the vertical
gas vent in all applications; however,
single-wall
metal pipe cannot be used for vertical gas vent in
residential applications.
3 - Keep the vent connector runs as short as possible
with a minimum number of elbows. Refer to the
current edition of ANSI Z223.1 or CSA-B149
installation compliance codes for maximum vent and
vent connector lengths.
4 - The entire length of a single-wall metal vent connector
shall be readily accessible for inspection, cleaning
and replacement.
5 - Single-wall, metal pipe used as vertical gas vent in
commercial applications must not pass through any
attic, interior wall, concealed space, or floor.
VENT TERMINATION ON SINGLE-WALL VERTICAL VENT RUNS
SINGLE-WALL VENT PIPE WITH
SINGLE-WALL TERMINATION
SINGLE-WALL VENT PIPE WITH
DOUBLE-WALL (TYPE B-1) TERMINATION
ROOF FLASHING
ROOF PITCHED
FROM 0” TO 45”
2” CLEARANCE
THIMBLE
CLEARANCE TO BE
AS SPECIFIED ON
TYPE “B” VENT PIPE.
12” MAX
ROOF FLASHING
ROOF PITCHED
FROM 0” TO 45”
SEAL JOINT BETWEEN SINGLE-WALL VENT AND “B” VENT TERMINATION
AND THE OPEN SPACE BETWEEN THE SINGLE WALL VENT PIPE AND
THE OUTER PIPE OF THE “B” VENT TERMINATION.
Commercial Application Only
24 INCHES (610mm) MIN.
+ SNOW DEPTH (MAX)
FOR THE AREA
24 INCHES (610mm) MIN.
+ SNOW DEPTH (MAX)
FOR THE AREA
FIGURE 6
