Horizontal And Vertical Vent Chart - PSG CADDY ALTERNA II Installation And Operating Instructions Manual

NOTE: Do not include the exterior wall termination in the EVL
calculation (45° elbow and termination).

5.7.5 HORIZONTAL AND VERTICAL VENT CHART

For example, let's imagine an installation consisting of a horizontal vent
coming out at the back of the furnace on a total distance of 8 feet. This
horizontal run is followed by a tee and a 6-foot vertical rise. This type of
installation is not acceptable. As you can see, the vent termination is clearly
outside the allowed configuration zone on the chart because the venting
system proposed does not have at least one foot of vertical rise for each
foot of horizontal run.
Instead, if the installation consisted of a horizontal vent coming out at the
back of the furnace on a total distance of 4 feet, followed by a tee and a 6-
foot vertical rise, it would be acceptable. The termination location should be
within the allowable configuration zone on the chart since it would have at
least one foot of vertical rise for each foot of horizontal run. Furthermore, the
total vertical rise would be at least 3-foot high.
WARNING: To reduce the risk of smoke spillage there should always be
at least one foot of vertical rise for each foot of horizontal run. In all
cases, at least 3 feet of vertical rise is needed.
24
Vertical lengths =
(2' + 3' + 2') X 0.5' =
3.5' EVL
90° elbow or "TE" =
(2 x 5') = 10' EVL
Horizontal lengths =
(4' + 2') = 6' EVL
Total EVL =
(3.5' + 10' + 6') =
19.5'
.
EVL
O.K.