12
3.4
DEFINITIONS
For the following symbols used in the venting calculations and examples are:
> - greater than
EN
> - equal to or greater than
< - less than
< - equal to or less than
H
- total of both horizontal vent lengths (Hr) and offsets (Ho) in feet
T
H
- combined horizontal vent lengths in feet
R
H
- offset factor: .03 (total degrees of offset - 135°*) in feet
O
V
- combined vertical vent lengths in feet
T
3.5
ELBOW VENT LENGTH VALUES
FEET
1°
0.03
15°
0.45
30°
0.9
45°*
1.35
90°*
2.7
* The fi rst 45° and 90°offset has a zero value and is shown in the formula as -45° and - 90° respectively or
-135° when combined.
W415-1332 / A / 11.21.14
INCHES
MILLIMETERS
0.5
12.7
6.0
152.4
11.0
279.4
16.0
406.4
32.0
812.8
14.2
15.2A