Rinnai EX38DT Installation And Operation Manual page 21

Guidelines
1. The maximum vent length is 13 feet (4 m) with 3 bends. The bent pipe attached to the furnace
does not count toward the max limit of 3 bends.
2. Horizontal sections should be sloped 3º to drain condensate. (3º equals 2/3 inch drop per foot of
vent.) The direction should be to the outside (if local codes allow) or toward the furnace.
3. Do not allow any low points in the exhaust line where condensate will collect.
4. Vent extensions installed in unconditioned air space.
5. Clearances:
 Exhaust pipe to combustibles: 1 in. (25.4 mm)
 Exhaust pipe to non-combustibles: 0 in. (0 mm)
1 Ft
Slope horizontal sections 3º (2/3 inch drop per foot of vent.)
Figure 19
Configurations
Correct Configurations
Figure 20
EX38DT Installation and Operation Manual
2/3 in.
3°
NOTE
The EX38DT is capable of two vent length
settings:
 Short Vent: 0 - 7 ft + 1 elbow
 Long Vent: 7 ft + 1 elbow - 13 ft + 3 elbows
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