16
01/21
7082-153K
F. Equivalent Feet of Pipe
The table below can help you calculate the equivalent feet
of pipe which is a method used to determine pellet vent size
(Figure 16.1)
.
Example of 3 Elbow-Rear Vent Termination Calculation
Figure 16.1
2 ft.
2 ft.
3 ft.
2 ft.
NOTE:
This is a generic example and is not intended to represent any specific fuel type.
Figure 16.2
3 in. or 4 in. (76mm or
102mm) Diameter Pipe
3 in. or 4 in. (76mm or
102mm) Diameter Pipe
Equivalent Pipe
Length In Feet
Equivalent Pipe
Length In Feet
ALTITUDE IN THOUSANDS OF FEET
ALTITUDE IN THOUSANDS OF FEET
0
20
30
1 2 3 4 5 6 7 8 9 10
4 in. (102mm) Diameter Pipe Only
4 in. (102mm) Diameter Pipe Only
10
Example 1
Example 1
Example 2
Example 2
Example 1:
If the equivalent length of pipe is 23 feet (7m)
with altitude of 8,000 feet (2438m) you must use 4 inch
(102mm) diameter type “L” or “PL” vent.
Example 2:
If the equivalent length of pipe is 12 feet (3.7m)
with altitude of 6,000 feet (1829m) you may use 3 or 4 inch
(76 to 102mm) diameter type “L” or “PL” vent.
G. Pipe Selection Chart
The chart will help you in determining proper venting size
according to the equivalent feet of pipe calculated previously
and the altitude above sea level of this installation (
Figure
16.2).
1. Locate the calculated equivalent feet of pipe on the
vertical left side of the chart.
2. Move to the right horizontally on the chart until you reach
your altitude above sea level.
3. If you fall below the diagonal line, 3 or 4 inch (76 to
102mm) pipe may be used.
4. If it is anywhere above the diagonal line, a 4 inch (102mm)
diameter pipe is required.
NOTICE:
A 90° elbow is 5 times as restrictive to the
flow of exhaust gases under positive pressure as 1 foot
(305mm) of horizontal pipe. A foot of horizontal pipe is
twice as restrictive as a foot of vertical pipe.
Pellet
Venting
Component
# of
Elbows
Feet of
Pipe Multiplied By
Equivalent
Feet
Components
Equivalent
Feet
90° Elbow
or Tee
3
X
5
15
45° Elbow
X
3
Horizontal
Pipe
7
X
1
7
Vertical
Pipe
2
X
0.5
1
Total Equivalent Feet
23
Table 16.1
Vent surfaces get HOT, can cause burns
if touched. Non-combustible shielding or
guards may be required.
WARNING
Risk of Fire!
•
Only LISTED venting components may
be used.
•
NO OTHER vent components may
be used.
•
Substitute or damaged vent components
may impair safe operation.
WARNING
Risk of Injury or Property Damage.
•
Improper
installation,
adjustment,
alteration, service or maintenance can
cause injury or property damage.
•
Refer to the owner’s information manual
provided with this appliance.
•
For assistance or additional information
consult a qualified installer, service
agency or your dealer.
WARNING
