Rinnai RUCS65i Installation And Operation Manual page 17

Maximum vent length
Maximum Vent Length with Twin Pipe PVC / CPVC
Twin Pipe 3" PVC / CPVC
(90° elbow is equivalent to 5 feet; 45° elbow is equivalent to 2.5 feet.)
Maximum Equivalent Vent Length 41 ft (12.5 m)
# of 90° Elbows
0
1
2
3
4
5
6
Twin Pipe 4" PVC / CPVC
(90° elbow is equivalent to 5 feet; 45° elbow is equivalent to 2.5 feet.)
Maximum Equivalent Vent Length 100 ft (30.5 m)
# of 90° Elbows
0
1
2
3
4
5
6
**SW 1 in DIPSW 1 is "OFF" for lengths greater than
or equal to 21 feet.
(See Twin Pipe PVC/CPVC Vent Installation section for
more information regarding equivalent vent length
calculations.)
Maximum Vent Length in feet
(meters)
41 (12.5)**
36 (11.0) **
31 (9.4) **
26 (7.9) **
21 (6.4) **
16 (4.9) **
11 (3.4) **
Maximum Vent Length in feet
(meters)
100 (30.5)**
95 (29.0) **
90 (27.4) **
85 (25.9) **
80 (24.4) **
75 (22.9) **
70 (21.3) **
KCM Series Manual 17