Installation Guide

Rinnai Tankless Water Heater Installation and Operation Manual 37

1. Direct Vent (Twin Pipe )

Twin Pipe Overview

Intake air and exhaust vent directly through separate penetrations.

Intake Air

Exhaust

12 in.

min

12 in.

min

12 in.

min

12 in.

min

60 in.

min

12 in.

min

Minimum clearance for

Ground/Grade/Snow Level

Indicates area in which intake

cannot be installed.

Figure 25: Horizontal Vent and Intake Air Piping

Figure 23

Twin Pipe Termination Clearances

Figure 24: Twin Pipe Vertical Termination of Multiple

Water Heaters

12 in. (0.30 m)

Minimum above

intake air

opening

Exhaust

Roof

Intake

Air

12 in. (0.30 m)

Above grade or

anticipated

snow level

Intake Air