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Installing the Water Heater
3.5.3 Measuring Vent Length (Indoor Models Only)
Refer to the table to find the maximum vent length based on the number of elbows. (Two 45 degree elbows
count as one 90 degree elbow.)
Vent Type
Diameter
Number of 90° Elbows
Maximum Vent Length
Concentric
3 in. / 5 in.
(80 mm / 125 mm)
0
20 ft (6 m)
1
15 ft (4.5 m)
2
10 ft (3.0 m)
3
5 ft (1.5 m)
Note
●
The Maximum Vertical and Horizontal (Total) Vent Length does not include any elbows.
●
Each 90° elbow is equivalent to 5 feet of vent length.
●
Two 45° elbows are equivalent to one 90° elbow.
●
The value in the table include the terminating vent length.
NaviVent Vent Components
Equivalent Length
3 ft (91 cm)
5 ft (1.5 m)
5 ft (1.5 m)
