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VENT EXAMPLES FOR SINGLE FLUE
Figure 3 displays a single flue (one-pipe) installation. Because the
distance from the heater to the first elbow is more than 6 inches,
the first 90° elbow does need to be considered into the total vent
length. The equivalent length of the second 90° elbow also needs
to be added to the total length, but the third elbow does not since
it is the flue terminal. The total horizontal vent length of the flue
system is 7 feet, and the total vertical length is 27 feet. The two 90°
elbows are equivalent to 6 feet, bringing the total to 40 feet.
Figure 4 is an example of how the heater can be vented if the flue
outlet is below the level of the floor.
2’
5’
27’
VENT TERMINAL
90° ELBOW
(NOT COUNTED)
90° ELBOW
3’
FIRST 90° ELBOW
DOES NOT GET COUNTED
WHEN WITHIN 6”
OFF BACK OF HEATER
Figure 3
Single Flue - Horizontal Tall Vent Run
Example Calculation Max Vent Run 40 feet
H =
5’ + 2’ = 7’
V =
27’
(2) - 90° = 6’
Total =
40’
Figure 4
Minimum Exterior Grade Dimension - Single Flue, Horizontal
Venting Below Floor
