12
VERTICAL TERMINATION
when (HT) < (VT) | Example 3: |
Simple venting confi gurations
FIGURE 10
FIGURE 11
90°
H2
45°V1
45°
H1 90°
See graph to determine the required vertical rise VT for the required horizontal run HT.
V2
90°
REQUIRED VERTICAL RISE
IN FEET (VT)
HORIZONTAL VENT RUN PLUS
OFFSETS IN FEET (HT)
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
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 confi guration is ac- ceptable.
