Demand Duo
™
H
-
Series Installation and Operation Manual
21
All terminations (horizontal and/or vertical)
must terminate 12 in. (0.30 m) above grade or
anticipated snow level.
12 in. (0.30 m)
Between terminals at same level
60 in. (1.52 m)
Between terminals at different levels
Note: 24 in. (0.61 m)
to wall or parapet
Combustion air and exhaust vent directly through
a single concentric connection. Hot exhaust exits
through the interior tube, while combustion air
enters through the outer layer.
Combustion
air
Exhaust
Concentric Pipe Termination Clearances
Direct Vent
(Concentric Pipe)
1
Concentric Pipe Overview
Combustion
air
Inside
Corner
12 in.
(0.30 m)
12 in.
(0.30 m)
60 in. (1.52 m)
vertically
between
terminals
Figure 14
Figure 15
Figure 16
Figure 17
