Lennox DT3025 Installation Instructions Manual page 14

VERTICAL VENTING WITHOUT ELBOWS
(DT/DTH - Top Vent Units)
Firestop/Spacer must be used any time
vent pipe passes through combustible
floor or ceiling or wall.
V
Install flashing and storm
collar at the point the vent pipe
passes through the roof.
FIGURE 16
V1 + V2 = 40 ft. Maximum.
H1 + H2 = 17 ft. Maximum.
V1 H1 + H2
1 ft. min. 3 ft. max.
2 ft. min. 6 ft. max.
3 ft. min. 9 ft. max.
4 ft. min. 12 ft. max.
5 ft. min. 15 ft. max.
6 ft. min. 17 ft. max.
DT/DTH VERTICAL VENTING FIGURES
V = 40 feet
Maximum
VERTICAL VENTING USING THREE 90
(DT/DTH - Top Vent Units)
V2
H2
FIGURE 18
P a g e 1 4
VERTICAL VENTING USING TWO 90
(DT/DTH - Top Vent Units)
V2
V1 + V2 = 40 ft. Maximum.
H = 17 ft. Maximum.
V1
1 ft. min.
2 ft. min.
3 ft. min.
4 ft. min.
5 ft. min.
6 ft. min.
FIGURE 17
ELBOWS
_
Firestop/Spacer must be used any
time vent pipe passes through
combustible floor or ceiling or wall.
H1
V1
ELBOWS
_
H
Firestop/Spacer must be used any
time vent pipe passes through
combustible floor or ceiling or wall.
V1
H
3 ft. max.
6 ft. max.
9 ft. max.
12 ft. max.
15 ft. max.
17 ft. max.