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VENT DRAIN - RUN TO SUITABLE
CONDENSATE COLLECTOR PER
APPROPRIATE CODES.
EXTRACTOR'S
PRESSURE
SET POINT
2X D
F10224
Horizontal Through-the-Wall
Direct Venting (Category IV)
Installation
These installations utilize the heater-mounted blower to
vent the combustion products to the outdoors. Combustion
air is taken from inside the room and the vent is installed
horizontally through the wall to the outdoors. Adequate
combustion and ventilation air must be supplied to the
equipment room in accordance with the NFGC (U.S.) or
B149 (Canada).
The total length of the horizontal through-the-wall flue
system should not exceed 75 equivalent ft (23 m) in
length. If horizontal run exceeds 75 equivalent ft (23 m),
an appropriately sized variable-speed extractor must be
used. Each elbow used is equal to 10 ft (3 m) of straight
pipe. This will allow installation in one of the four following
arrangements:
•
75' (23 m) of straight flue pipe
•
65' (20 m) of straight flue pipe and one elbow
•
55' (17 m) of straight flue pipe and two elbows
•
45' (14 m) of straight pipe and three elbows
28
SLOPE TOWARD
APPLIANCE 1" IN 4' MIN
(21 mm per m)
D
Figure 27. Typical Common Venting
VARIABLE SPEED
EXTRACTOR
COMMON VENT
PIPE (CAT II)
ADJUSTABLE VENT
BAFFLE (IF REQUIRED)
VENT PIPE SAME DIAMETER
AS BOILER VENT (CAT IV)
TEST PORT
BOOT TEE
VENT DRAIN - RUN TO
SUITABLE CONDENSATE
COLLECTOR PER APPROPRIATE
CODES.
The vent cap is not considered in the overall length of the
venting system.
The vent must be installed to prevent flue gas leakage.
Care must be taken during assembly to ensure that all
joints are sealed properly and are airtight. The vent must
be installed to prevent the potential accumulation of
condensate in the vent pipes. It is required that:
1. The vent must be installed with a condensate drain
located in proximity to the heater as directed by the
vent manufacturer.
2. The vent must be installed with a slight upward slope
of not less than 1/4 inch per foot (21 mm per m) of
horizontal run to the vent terminal.
3. The vent must be insulated through the length of the
horizontal run.
ALT. LOCATION
VARIABLE SPEED
EXTRACTOR
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