Rinnai CU199i - Page 19

Rinnai Tankless Water Heater Installaon and Operaon Manual 19
Three types of venng opons are available:
Concentric Pipe
Combuson air and exhaust vent directly through a
single concentric connecon. Hot exhaust exits
through the interior tube, while combuson air enters
through the outer layer.
Exhaust
Exhaust
Combuson
air
Combuson
air
Combuson
air
Combuson
air
Exhaust
Direct Vent
Non-Direct (Room Air) Vent
Mulple water heaters sharing a combuson air header
and a separate exhaust header that vents directly through
separate penetraons to the outside.
Combuson Air
Exhaust
Exhaust
Room Air
For Combuson
Twin Pipe
Combuson air and exhaust vent directly through
separate penetraons.
Room Air
Room air is used for combuson while exhaust
vents to the outside.
External (Outdoor)
External (outdoor) water heater.
Exhaust
Combuson
air
Mulple water heaters using room air for combuson
while sharing an exhaust header that vents directly to
the outside.
Select a Vent Type
Direct Vent (Concentric Pipe and Twin Pipe)
1
Non-Direct Vent (Room Air and External)
2
Common Vent (Indoor Units Only. Direct Vent and Non-Direct/Room Air Vent)
3