Installation and Operation Manual

28 Rinnai Tankless Water Heater Installation and Operation Manual
4.5.4 Venting Options

1. Direct Vent (Concentric Pipe and Twin Pipe)
2. Non-Direct Vent (Room Air and External)
3. Common Vent (Indoor Unit Only. Direct Vent and Non/Direct/Room Air Vent)




exhaust exits through the interior





through separate





External (Outdoor)




air header and a separate exhaust header that






Figure 15: Concentric Pipe
Figure 16: Twin Pipe
Figure 17: Room Air
Figure 18: External
Figure 20: Common Vent, Room Air
Figure 19: Common Vent, Direct Vent