Rinnai HE Series How To Use Manual page 22

Maximum vent length
Maximum Equivalent Vent Length for Duravent:
Determine the number of 90 degree elbows in the vent system. (two 45 degree elbows count as one 90 degree
elbow.) Refer to the guidelines and tables below to find the maximum vent length based on the number of
elbows.

Comply with the exhaust clearances found in the Rinnai Installation and Operation Manual.

Only one appliance can be attached to the vent system.

Install the system in according to the DuraVent installation instructions.

The vent termination and air intake must be in the same pressure zone.

Do not exceed maximum straight vent length with number of elbows as shown in the tables in the following
section.

Refer to vent manufacturer's instructions for further information.
Number of 90° Elbows
0
1
2
3
4
5
6
Each termination will be equivalent to the length of pipe of the termination.
12
Maximum Straight Vent Length
41 ft (12.50 m)
35 ft (10.67 m)
29 ft (8.84 m)
23 ft (7.01m)
17 ft (5.18 m)
11 ft (3.35 m)
5 ft (1.52 m)
KBD Series Manual
SW1 in DIPSW 1
If length is greater than:
21 ft (6.40 m) move SW1 to OFF
15 ft (4.57 m) move SW1 to OFF
9 ft (2.74 m) move SW1 to OFF
3 ft (0.91 m) move SW1 to OFF
move SW1 to OFF
for any length