Lennox Cascade Installation And Operation Manual page 13

Determining Size Of Pipe To Install
To determine what diameter pipe to use in an installation (3" or 4"), first
find the "equivalent pipe length" using the following guidelines, then plot
the number and the altitude on the installation chart (Figure 12).
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 (Figure 12) to determine if your installation requires 3"
or 4" exhaust pipe.
Installation Chart
Type of Pipe # of Elbows or
Feet of pipe
90° Elbows /
Tee (A & G)
45° Elbows
(C)
Horizontal
(B & F)
Vertical(E)
Table 2
Sample Installation Chart
Type of Pipe # of Elbows or
Feet of pipe
90° Elbows / 
Tee (A & G)
45° Elbows 1
(C)
Horizontal 3
(B & F)
Vertical (E) 8
Table 3
- Sample Chart for Figure 13
Equivalent Feet Total Equivalent
Feet
x 5 Ft. (1.5 m)
x 3 Ft. (1 m)
x 1 Ft. (.3m)
x .5 Ft. (.15m)
Equivalent Feet Total Equivalent
Feet
x 5 Ft. (1.5 m) 10 (3m)
x 3 Ft. (1 m) 3 (1m)
x 1 Ft. (.3m) 3 (1m)
x .5 Ft. (.15m) 4 (1.m)
Total Equivalent Feet = 0
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE
30
0
3 or 4"
Diameter
10
0
0 1  3 4
Altitude x 1000 Feet
Figure 12
- Pipe Selection Chart
NOTE: All equivalent pipe styles
shown are standard for all free-
standing models.
A- 90 Degree Elbow
B- 1' Horizontal Pipe
C- 45 Degree Elbow
D- Standoff Braces
E- 8' Vertical Pipe
F- ' Horizontal Pipe
G- 90 Degree Tee
H- Wall Thimble
Figure 13
- See Sample Installation Chart
4" Diameter Only
5 6 7 8 9 10
A
D
E
F
G
H
B
C
13