12
VERTICAL TERMINATION
when (HT) < (VT)
Simple venting configurations
FIGURE9
Example 3:
FIGURE10
V2
90° H2
45°
45° H1
90°
V1
See graph to determine the required vertical rise VT for the required horizontal run HT.
REQUIRED VERTICAL RISE IN
FEET (VT)
HORIZONTAL VENT RUN
PLUS OFFSETS IN FEET (HT)
90°
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 10.9 < 15
Formula 2: HT + VT < 40 feet
25.9 < 40
Since both formulas are met, this vent configuration is ac- ceptable.
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
