Maximum Vent Lengths; 4: Ng Units Total Vent Length For Twin Pipe - Rinnai RU80i Manual

OPTION 2: Maximum Equivalent Vent Length Tables:
1. Determine the number of 90 degree elbows in the vent system. (two 45 degree elbows count as one 90
degree elbow.)
2. Refer to Tables 4-7 to find the maximum vent length based on the number of elbows and termination style.
Total Equivalent Vent Length (Intake/outlet) for Twin Pipe 3" PVC/CPVC
Maximum Vent Length
Termination Type
Termination Equivalent Length in feet
(meters) (Already factored into the
straight pipe lengths below)
# of 90° Elbows (each: 5 equivalent feet)
0
1
2
3
4
5
6
Total Equivalent Vent Length (Intake/outlet) for Twin Pipe 4" PVC/CPVC
Maximum Vent Length
Termination Type
Termination Equivalent Length in feet
(meters) (Already factored into the straight
pipe lengths below)
# of 90° Elbows (each: 5 equivalent feet)
0
1
2
3
4
5
6
**Dip switch one (bank of eight - TAN COLORED) off for lenths greater than or equal to 21 feet
Maximum vent lengths are specific to the fuel type of the tankless water heater. It is imperative when performing
equivalent vent length calculations, that the gas type be taken into consideration.
Table 4 - Natural Gas Units
IPEX
Concentric
Vent Kit
20 (6.1)
Max. straight pipe vent length in feet (meters)
45 (13.7) **
40 (12.2) **
35 (10.7) **
30 (9.1) **
25 (7.6) **
20 (6.1) **
15 (4.6) **
Table 5 - Natural Gas Units
IPEX
Concentric
Vent Kit
20 (6.1)
Max. straight pipe vent length in feet (meters)
80 (24.4) **
75 (22.9) **
70 (21.3) **
65 (19.8) **
60 (18.3) **
55 (16.8) **
50 (15.2) **
ATTENTION
10
65 Feet
Snorkel Side Wall Tee
Termination Termination
10 (3.0) 5 (1.5)
55 (16.8) ** 60 (18.3) **
50 (15.2) ** 55 (16.8) **
45 (13.7) ** 50 (15.2) **
40 (12.2) ** 45 (13.7) **
35 (10.7) ** 40 (12.2) **
30 (9.1) ** 35 (10.7) **
25 (7.6) ** 30 (9.1) **
100 Feet
Snorkel Side Wall Tee
Termination Termination
10 (3.0) 5 (1.5)
90 (27.4) ** 95 (29.0) **
85 (25.9) ** 90 (27.4) **
80 (24.4) ** 85 (25.9) **
75 (22.9) ** 80 (24.4) **
70 (21.3) ** 75 (22.9) **
65 (19.8) ** 70 (21.3) **
60 (18.3) ** 65 (19.8) **
Low Profile
Termination
5 (1.5)
60 (18.3) **
55 (16.8) **
50 (15.2) **
45 (13.7) **
40 (12.2) **
35 (10.7) **
30 (9.1) **
Low Profile
Termination
5 (1.5)
95 (29.0) **
90 (27.4) **
85 (25.9) **
80 (24.4) **
75 (22.9) **
70 (21.3) **
65 (19.8) **