12.1
Feet Inches
Millimeters
1°
0.03 0.5
12.7
15°
0.45 6.0
152.4
30°
0.9
11.0
279.4
45°
1.35 16.0
406.4
90°* 2.7
32.0
812.8
* The fi rst 90° offset has a zero value and is shown in the formula as - 90°
* The fi rst 45° and° offset have a zero value and is shown in the formula as -45° and -90°
respectively or -135° when combined (for 45° exit only).
3.4 ELBOW VENT LENGTH VALUES
3.3 DEFINITIONS
11.1
For the following symbols used in the venting calculations and
examples are:
> - greater than
> - equal to or greater than
< - less than
< - equal to or less than
H
T
- total of both horizontal vent lengths (Hr) and offsets (Ho) in feet
H
R
- combined horizontal vent lengths in feet
H
O
- offset factor: .03 (total degrees of offset - 90°*) in feet
H
O
- offset factor: .03 (total degrees of offset - 135°*) in feet
V
T
- combined vertical vent lengths in feet
W415-2207 / A / 08.28.17
12
EN
