12
VERTICAL TERMINATION
When (HT) < (VT)
Simple venting confi gurations
FIGURE 9
45°
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)
Example 3:
V2
FIGURE 10
90°
H2 90°
45° V1
H1 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 acceptable.
The shaded area within the lines represents acceptable values for HT and VT.
For vent confi gurations requiring more than one 45º and one 90° elbow , the following formulas apply:
Formula 1: HT < VT
Formula 2: HT + VT < 40 feet