GF-5050
Innovation Series & ReCon Water Heater
TAG-0043_0Q
Venting and Combustion Air Guide
Page
38
of
39
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, New York 10913
•
Phone: 800-526-0288
12/01/2016
Example using metric units of measure:
1) An installer is trying to figure out if he can save some money by using a 101.6 mm vent
(exhaust) design versus a 152.4 mm vent when installing a single Innovation 600 water heater.
After laying out the design, he determines he needs the following components:
c) A 4.6 meter length of combustion air pipe with one (1) sharp 90° elbow plus (2) two
termination 90° elbows.
d) A 10.7 meter length of vent pipe and two (2) sharp 90° elbows plus a termination (exit
cone or rain cap).
Intake (must use 152 mm):
From
Table 4
for 152 mm piping we will design the inlet for maximum outside air temperatures
(37.8°C):
Max outside air Temp = 37.8°C
∆
p straight pipe =
0.24 m/m
∆
p 90° elbow = 0.38 m/elbow
∆
p entrance loss = 0.59 m
Intake
∆
p equivalent feet = 4.57 m x
0.24 m/m
+ 3 elbows x 0.38 m/elbow + 0.59 m. = 3.05 m
Vent using 152 mm pipe (Exhaust):
From
Table 8
for 152 mm piping:
∆
p straight pipe =
0.3 m/m
∆
p 90° elbow = 0.52 m /elbow
Velocity cone or Rain cap = 0.91 m
Exhaust
∆
p equivalent feet = 10.7 m x 0.3 m/m + 2 elbows x 0.52 m/elbow + 0.91 m = 5.2 m
Vent using 4” pipe (Exhaust):
From
Table 8
for 102 mm piping:
∆
p straight pipe =
2.2 m/m
∆
p 90° elbow = 3.69 m/elbow
Velocity cone or Rain cap = 6.0 m
Exhaust
∆
p equivalent feet equals:
10.7 m x
2.2 m/m
+ 2 elbows x 3.69 m/elbow + 6.0 m =
36.9 m > 24.4 m --FAIL--
iii)
Total equivalent feet of intake (152 mm) and vent (152 mm) =
3.1 m + 5.2 m = 8.2 m -APPROVED-
iv)
Total equivalent feet of intake (152 mm) and vent (152 mm) =
3.1 m +
36.9 m
= 39.9 m
--FAIL--
Only the 152 mm design is approved. Note that the 102 mm vent pipe design failed even
though the total equivalent feet for the combined intake and vent system was less than 42.7
m. The 102 mm vent design exceeded the equivalent 24.4 m maximum.
