Installation Guide

Rinnai Tankless Water Heater Installation and Operation Manual 35
1. Direct Vent (Concentric Pipe )
Concentric Pipe Overview
Intake air and exhaust vent directly through a
single concentric connection. Hot exhaust
exits through the interior tube, while fresh air
enters through the outer layer.
Exhaust
Figure 15: Concentric Pipe
Figure 16: Between terminals at different
levels
Figure 14: Concentric Pipe Termination
Clearances
Figure 17: Between terminals at same level
All terminations (horizontal and/or vertical) must terminate 12 in. (0.30 m) above grade or
anticipated snow level.
Intake
air
Intake
air