12
VERTICAL TERMINATION
when (HT) < (VT) | Example 3: |
Simple venting configurations |
|
FIGURE 9 | FIGURE10 |
|
V2
45°
See graph to determine the required vertical rise VT for the required horizontal run HT.
90° H2
V1
45°
H1 90°
90°
REQUIRED VERTICAL RISE IN FEET (VT)
V1 | =5 ft | |
V2 | =10 ft | |
VT | = V1 + V2 = 5 + 10 = 15 ft | |
H1 | =3 ft | |
H2 | =2.5 ft | |
HR | = H1 + H2 = 3 + 2.5 = 5.5 ft | |
HO | = .03(one 45º elbow + three 90º elbows - 135º) | |
| ||
HT | =HR + HO = 5.5 + 5.4 = 10.9 ft | |
HT + VT = 10.9 + 15 = 25.9 ft | ||
Formula 1: | HT < VT | |
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| 10.9 < 15 |
Formula 2: | HT + VT < 40 feet | |
25.9 < 40
Since both formulas are met, this vent configuration is ac- ceptable.
HORIZONTAL VENT RUN
PLUS OFFSETS IN FEET (HT)
The shaded area within the lines represents acceptable values for HT and VT.
For vent configurations requiring more than one 45º and one 90° elbow , the following formulas apply:
Formula 1: HT < VT
Formula 2: HT + VT < 40 feet