CYCLONE Xi COMMERCIAL GAS WATER HEATER
BTH 120 thru 500 SERVICE HANDBOOK
A.O. Smith – Technical Training Department
10
Ashland City, Tennessee © 200
9
Servicing should only be performed by a Qualified Service Agent
316586-000
VENTING TABLES BTH 120 – 250
Maximum equivalent feet of intake and vent pipe using 3” PVC is 50 feet (15.2m). Equivalent feet
must include any 90° elbows (two 45° elbows equal one 90° elbow). Three inch diameter 90° elbows
are equivalent to 5' (1.5m) of pipe.
Maximum equivalent feet of intake and vent pipe using 4” PVC is 120 feet (36.6m).
Equivalent feet must include any 90° elbows (two 45° elbows equal one 90° elbow). Four inch
diameter 90° elbows are equivalent to 5' (1.5m) of pipe.
VENTING TABLES BTH 300,400,500
Number of
90°Elbows
4" PVC
Maximum Feet / meters of Pipe
ONE (1)
65' / 19.7 m
TWO (2)
60' / 18.2 m
THREE (3)
55' / 16.7 m
FOUR (4)
50' / 15.2 m
FIVE (5)
45' / 13.6 m
SIX (6)
40' / 12.1 m
Vent Length Table Equivalent Feet (Meters) 300,400,500
Number of 90°
Elbows
3" Minimum
Pipe (Ft./M.)
3" Maximum
Pipe (Ft./M.)
4"Maximum
Pipe (Ft./M.)
ONE (1)
7/2.1
45/13.7
115/35
TWO (2)
7/2.1
40/12.2
110/33.5
THREE (3)
7/2.1
35/10.7
105/32
FOUR (4)
7/2.1
30/9.1
100/30.5
FIVE (5)
7/2.1
---
95/29
SIX (6)
7/2.1
---
90/27.4
Vent Length Table Equivalent Feet (Meters) 120 through 250