Rheem RTG-3 Series Use And Care Manual page 22

INSTALLATION INSTRUCTIONS
Venting for Direct-Vent Water Heater
Vent Lengths
Before starting the vent installation, careful
planning should be given to the routing and
termination of the vent pipes. The length of the
vent pipes (inlet and outlet) should be kept to
a minimum. Also, see pages 27,28, and 29 for
vent terminal placement. Refer to the maximum
and minimum vent length charts for the pipe
sizes that can be used and the total equivalent
length of pipe that can be used. DO NOT exceed
equivalent length of pipe in maximum vent length
chart.
SINGLE UNIT: MAX. EQUIVALENT VENT
Number of
90° ELbows
0
1
2
3
4
5
6
The vent termination is not included in the equivalency calculations.
NOTICE: A 90 degree standard bend concentric elbow is equivalent to 1 ft, 6 in. A 45 degree standard
bend concentric elbow is equivalent to 9 in.
22
LENGTHS - STRAIGHT PIPE
Max Length 3"/5" Straight Pipe
43 ft. (13.1 m)
41.5 ft. (12.6 m)
38.5 ft. (12.2 m)
34 ft. (11.7 m)
28 ft. (11.3 m)
20.5 ft. (10.8 m)
11.5 ft. (10.4 m)
DO NOT USE Schedule 20, Cell Core, Drain Pipe,
Galvanized, Aluminum or B-Vent.
EQUIVALENT FT. OF ELBOWS
90°
45°
3" / 5"
1.6 ft.
9 in.