Equivalent Vent Length (Evl) - Drolet Edison Installation And Operation Manual

Edison Installation and Operation Manual

4.3 Equivalent Vent Length (EVL)

Recommended venting system inner pipe diameter is 3". Use a 4" pipe if you have more
than 15 feet of Equivalent Vent Length (EVL).
To calculate the EVL of your installation, use the following conversions:
NOTE: Horizontal runs shall not exceed 9 feet.
NOTE: Never exceed 30 feet of EVL.
Here is an example to help you calculate Equivalent Vent Length. On the following figure
the EVL can be calculated like this:
• 2 horizontal run of 1' = (2 X 1') X 1' = 2' of EVL
• 1 elbow 90° or "Tee" = 5' of EVL
• 3 vertical length of 4' = (3 X 4') X 0.5' = 6' of EVL
• Total EVL = (2' + 5' + 6') = 13'.
NOTE: Do not include the exterior wall termination in the EVL calculation (45° elbow
and termination).
18
Qty Type of pipe
1 90° elbow or "T"
1 45° elbow
1 ft Horizontal pipe run
1 ft Vertical pipe run
EVL equivalent(ft)
5
3
1
0.5