Rinnai Sensei CU199i Installation And Operation Manual page 39

1. Direct Vent
Twin Pipe Overview
Combustion air and exhaust vent directly through separate penetrations.
Twin Pipe Termination Clearances
12 in. (0.30 m)
minimum
Exhaust
12 in. (0.30 m)
minimum above
combustion air
opening
Roof
Figure 32: Twin Pipe Vertical
Termination of Multiple Water Heaters
Rinnai Tankless Water Heater Installation and Operation Manual
(Twin Pipe)
12 in. (0.30 m)
minimum
Combustion
12 in. (0.30 m) above
grade or anticipated
snow level
Air
12 in.
min
12 in.
min
Minimum clearance for
Ground/Grade/Snow Level
Indicates area in which intake cannot be installed.
Figure 33: Horizontal Vent and Combustion
Air Piping
Figure 31
Intake
60 in.
min
12 in.
min
12 in.
min
Exhaust
Intake
12 in.
min
39