13
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE
Determining Size Of Pipe To Install
To determine what diameter pipe to use in an installation (3” or 4”), fi rst
fi nd the “equivalent pipe length” using the following guidelines, then plot
this Figure and the altitude on the chart.
Fill out the installation chart, and calculate your total equivalent pipe
length. After you have the total equivalent pipe length, use the Pipe
Selection Chart below to determine if your installation requires 3” or 4”
exhaust pipe.
Installation Chart
4 Inch Diameter Only
3 or 4 Inch
Diameter
Altitude x 1000 Feet
Equivalent Pipe Length (Feet)
30
20
10
0
0
1
2
3
4
5
6
7
8
9
10
Figure 19
- Pipe Selection Chart
A
B
C
D
E
F
G
H
Figure 20
- See Sample Installation Chart
A- 90 Degree Elbow
B- 1’ Horizontal Pipe
C- 45 Degree Elbow
D- Standoff Braces
E- 8’ Vertical Pipe
F- 2’ Horizontal Pipe
G- 90 Degree Tee
H- Wall Thimble
NOTE:
All equivalent pipe styles
shown are standard for all free-
standing models.
Type of Pipe
# of Elbows or
Feet of pipe
Equivalent Feet
Total Equivalent
Feet
90° Elbows /
Tee (A & G)
x
5 Feet
(1.5 meters)
45° Elbows
(C)
x
3 Feet
(1 meters)
Horizontal
(B & F)
x
1 foot
(.3 meters)
Vertical(E)
x
.5 Feet
(.15 meters)
Table 5
Sample Installation Chart
Type of Pipe
# of Elbows or
Feet of pipe
Equivalent Feet
Total Equivalent
Feet
90° Elbows /
Tee (A & G)
2
x
5 Feet
(1.5 meters)
10 Feet
(3 meters)
45° Elbows
(C)
1
x
3 Feet
(1 meter)
3 Feet
(1 meters)
Horizontal
(B & F)
3
x
1 foot
(.3 meters)
3 Feet
(1 meter)
Vertical(E)
8
x
.5 Feet
(.15 meters)
4 Feet
(1.2 meters)
Table 6
- Sample Chart for Figure 16
