Common Vent Piping - 199 Model Only; Vent Diameter Sizing And Lengths - Westinghouse Premium WGRT 199 Series Installation, Start-Up, Maintenance, Parts, Warranty

I. Common Vent Piping - 199 Model Only!
DO NOT ATTEMPT to common vent 150 model water heaters! Doing
so will result in property damage, severe personal injury, or death.
Common Vented units must be direct vented, with an exhaust vent
and intake air pipe vented to the outdoors. DO NOT power vent
Common Vented units! Doing so will result in property damage,
severe personal injury, or death.
These units can be common vented. Connecting several units together
requires proper sizing of the intake and exhaust pipes. Up to eighteen
(18) units can be common vented together.
Maximum Vent Length (in Ft.) for Direct Vent (2 Pipe)
Number of Units Load
Common Vented (BTU/Hr)
1 199,000
2 398,000
3 597,000
4 796,000
5 995,000
6 1,194,000
7 1,393,000
8 1,592,000
9 1,791,000
10 1,990,000
11 2,189,000
12 2,388,000
13 2,587,000
14 2,786,000
15 2,985,000
16 3,184,000
17 3,383,000
18 3,582,000
Table 20 - Maximum Common Vent Length for Direct Vent (2 Pipe)
NOTE: Reduce the maximum equivalent length above by 5 feet per
o
90 elbow used and by 2 feet per 45
above set limits.

1. Vent Diameter Sizing and Lengths

These units are designed for 3 inch exhaust vent and intake pipes. The
following chart outlines the maximum length of common venting
allowable. A vent system's length is calculated by adding the length
of all straight pieces used (both horizontal and vertical) and then
adding the equivalent lengths of each fitting used in the system. A
vent system's length must not exceed the maximum length outlined
in the chart below.
Pipe Size
3" 4" 6" 8" 10"
100 100
N/A
50 83
58 133 N/A
101
N/A
75
67 117
58 99
89
79 124
71 110
N/A
N/A 65 101
59 92
N/A 86
79
74
N/A
70
65
62
o
elbow used. DO NOT exceed the
12"
N/A
114
107
101
N/A
whl-004 Rev. 000 Rel. 013 Date 5.1.18
35