27297-5-0511
Page 13
DIRECT VENT AND COLINEAR VENT EXAMPLES
Figure 5 displays a two-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.
The third elbow also needs to be included. The equivalent
length of the PTrap does not need to be added since it is
the termination. The total horizontal vent length of the flue
system is 11 feet, and the total vertical length is 20 feet. The
three 90° elbows are equivalent to 9 feet, bringing the total
to 40 feet.
Note: The exhaust must be a minimum of 3 inches above
the inlet air pipe. The flue must be at least 12 inches from
the roof line, and it is recommended to be at least 12 inches
above the maximum expected snow level as indicated in
Figures 5 through 8.
12” MIN TO GRADE
(RECOMMENDED 12” MIN.
TO MAX EXPECT SNOW LEVEL)
6” MIN.
9” MIN.
3” MIN.
2” MIN.
Figure 6
3” MIN.
12” MIN. TO ROOF
(RECOMMENDED 12”
MIN TO MAX. EXPECTED
SNOW LEVEL)
PTRAP
90° ELBOW
3’
COLINEAR ADAPTER
5’
10’
FIRST 90° ELBOW
DOES NOT GET COUNTED
WHEN WITHIN 6” FROM THE
BACK OF HEATER
H = 5’ + 6’ = 11’
V = 10’ + 10’ = 20’
(3) 90° = 9’
= 40’
TOTAL
6’
90° ELBOW
3’
10’
Figure 5
Calculation example of vent run maximum 40 feet
Note:
Exhaust must be a
minimum of 3 inches above
air intake inlet.
6” MIN.
12” MAX.
SUPPORT
OUTSIDE
WALL
1/2”
ARMAFLEX
INSULATION OR
EQUIVALENT
(IF REQUIRED)
12” ABOVE
MAXIMUM
EXPECTED
SNOW LEVEL
Figure 7
