Rinnai Demand Duo CX Series Installation Instructions Manual page 21

1 Direct Vent
Concentric Pipe Overview
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.
Figure 15
Exhaust
Combustion
air
Concentric Pipe Termination Clearances
Figure 16
12 in.
(0.30 m)
Inside
Corner
All terminations (horizontal and/or vertical)
must terminate 12 in. (0.30 m) above grade or
anticipated snow level.
Demand Duo H-Series with SENSEI CX Installation Instructions
(Concentric Pipe)
Combustion
air
12 in.
(0.30 m)
60 in.(1.52 m)
vertically
between
terminals
Figure 17
60 in. (1.52 m)
Between terminals at different levels
Figure 18
12 in. (0.30 m)
Between terminals at same level
Note: 24 in. (0.61 m)
to wall or parapet
21