Owner`s manual

Equivalent Vent Length (EVL)

The longer the run of pipe in your installation, the greather the restriction there is in the system. Therefore, larger diameter pipe should be

used.

• Use 4” pipe if you have more than 15 feet of Equivalent Vent Length (EVL).

• Horizontal runs shall not exceed 10 feet of EVL.

• To calculate EVL, use the following conversions table:

Qty Type of pipe EVL equivalent(ft)

1 90° elbow or “T” 5

1 45° elbow 3

1 ft Horizontal pipe run 1

1 ft Vertical pipe run 0.5

NOTE: At altitudes above 3,000 feet, we suggest the use of 4” diameter vent at an EVL of 7 feet or more.

Here is an exemple on how to calculate the EVL of your installation. (See Figure 8)

(3 x 4’ of vertical length = 12’ x 0.5 = 6 EVL) + (1 x elbow or "T" = 5 EVL) + (2 x 1’ of horizontal length = 2 EVL)

Total EVL = (6 + 5 +2) = 13. So 3” diameter vent is acceptable

Note: Do not count the outside termination (goose neck) in the EVL calculation.

INSTALLATION CONFIGURATIONS

Termination Location

Termination should not be located so that hot exhaust gases can be a hazard. They can reach temperatures of 500 ºF and cause serious

burns.

CAUTION:

TERMINATION COLLAR (SPARK ARRESTER) IS MANDATORY.

Refer to NFPA 211 (USA) or CSA B365 (Canada) for rules for the distance of exit terminal from windows and openings. The exit terminal of

a mechanical draft system, other than a direct vent appliance shall be located in accordance with the following.

Permitted Termination Location

TALLATI