Figure 30. Possible Vent Configurations
for Top Vent Only. Vertical and Horizontal
Terminations
Initial Installation
QUALIFIED INSTALLERS ONLY
a
LLowabLe
c
o
-a
xiaL
v
ent
c
onfiguRations
:
Figures 30 shows the range of venting options for
top vented configurations only
using either vertical
or horizontal terminations; any layout that remains within the shaded area is acceptable. Having the
fewest number of elbows is ideal as they tend to disrupt air movement. Using 45˚ elbows is preferable to
using 90˚ elbows. Also, a shorter vent system will perform better than a longer one. The total length of
horizontal vent pipe can not exceed 20 feet (6.1m) and the total vent length can not exceed 40ft (12.2m).
Any combination of rise and run can be
used as long as it lays within the shaded
area (a total of three (3) 90
˚
elbows or six
(6) 45
˚
elbows can be used. In addition
to what is shown, if a 90
˚
elbow is used
in the horizontal plane, 3 feet (91.4cm)
must be subtracted from the allowable
horizontal run (for each 45
˚
elbow, 1½
feet must be subtracted).
Page 28
0’
(0m)
5’
(1.52m)
0’
(0m)
5’
(1.52m)
10’
(3.05m)
10’
(3.05m)
15’
(4.57m)
15’
(1.52m)
20’
(6.1m)
20’
(6.1m)
25’
(7.62m)
30’
(9.14m)
35’
(10.7m)
40’
(12.2m)
Vent
Position
10-20FT
Restrictor
20-40FT
Restrictor
Restrictor not required.
High wind guard required for all vertical
vent runs with no horizontal run.
ICC EXCELDirect TM-SVTS
M&G Duravent Pro 46DVA-VWG
**Vertical vent height does not account for elbows
