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13 - All horizontal vents which use special vent pipe for
use with Category III appliances must terminate
with a listed termination tee. Termination must
be installed in accordance with manufacturer’s
instructions.
14 -
For horizontal venting, the vent pipe shall be
supported with hangers no more than 3 feet (1m)
apart to prevent movement after installation.
15 - Select a wall termination point that will maintain
either a 1/4” (6mm) per foot (305mm) rise (upward
slope) or a 1/4” (6mm) per foot fall (downward
slope) of horizontal run of vent pipe.
16 - For upward sloped vent, a condensate tee and
drain must be installed within the first 5 feet (1.5m)
from the unit heater to protect the appliance (see
figure 7). If a flexible condensate drain line is used,
the drain line must include a loop filled with water
to prevent combustion products from entering the
structure. If the unit is shut down for an extended
period of time and will be exposed to sub-freezing
temperatures, the condensate may freeze.
17 - For downward sloped vent, condensate drainage
can be collected in a tee pipe section (figure 8) with
drain loop similar to one used for upward slope vent,
or allowed to drip through the vent termination, if
permitted by authorities (figure 9).
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CONDENSATE DRAIN THROUGH TEE PIPE AND DRAIN LOOP
FLUE TRANSITION
(PROVIDED)
12” (30.5CM)
MINIMUM ABOVE
HIGHEST SNOWFALL
16 INCHES MIN.
(41 CM )
GROUND LEVEL
UPWARD SLOPE ON HORIZONTAL VENT -- RESIDENTIAL OR COMMERCIAL APPLICATION
COMMON VENTING NOT ALLOWED WHEN HORIZONTALLY VENTING THE UNIT HEATER.
COMBUSTION
AIR INDUCER
Category III adaptor
must be installed
before optional elbow
(if used).
LISTED WALL
THIMBLE
THROUGH
COMBUSTIBLE
WALL
NOTE - Minimum horizontal vent length is 5 ft.
This does not include termination tee. Refer to
table 4 for maximum length and number of elbows.
VENT
TERMINATION
TEE
DRAIN
TEE
DRAIN LOOP (PROVIDED BY
INSTALLER WITH WATER TRAP
TO CONDENSATE DRAIN
RESIDENTIAL APPLICATIONS --
Venting must be listed special
vent for Category III appliances.
COMMERCIAL APPLICATIONS
-- Venting may be single-wall (26
Ga) galvanized or equivalent
stainless steel vent pipe sealed
per these instructions, OR listed
special vent for Category III
appliances.
SLOPE = 1/4 IN. PER FOOT
RUN MAXIMUM.
FIGURE 7
DRAIN TEE
−
COMMON VENTING
NOT ALLOWED WHEN
HORIZONTALLY
VENTING THE
UNIT HEATER.
LISTED THIMBLE
THROUGH
COMBUSTIBLE
WALL
16 INCHES
MIN. (41 CM)
CONDENSATE DRAIN THROUGH TEE PIPE AND DRAIN LOOP
DOWNWARD SLOPE ON HORIZONTAL VENT − RESIDENTIAL OR COMMERCIAL APPLICATION
VENT
TERMINATION
TEE
Category III
adaptor must
be installed
before
optional
elbow
(if used).
DRAIN LOOP WITH WATER
TRAP TO CONDENSATE
DRAIN
(Provided by installer)
RESIDENTIAL APPLICATIONS −− Venting must be
listed special vent for Category III appliances.
COMMERCIAL APPLICATIONS −− Venting may be
single−wall (26 Ga) galvanized or equivalent
stainless steel vent pipe sealed per these instructions,
OR listed special vent for Category III appliances.
SLOPE = 1/4 IN. PER FOOT RUN MAXIMUM.
NOTE − Minimum
horizontal vent length is
5 ft. This does not
include termination tee.
Refer to table 4 for
maximum length and
number of elbows.
FIGURE 8
