Vent Application Fl Ow Chart; Defi Nitions; Elbow Vent Length Values - Napoleon Ascent BL42NTE Installation Manual

3.3 vent application fl ow chart
Horizontal Termination
Vertical rise is equal
to or greater than the
horizontal run
Horizontal run +
vertical rise to
maximum of
40 feet (12.2m)
3.4 defi nitions
For the following symbols used in the venting calculations and
examples are:
> - greater than
> - equal to or greater than
< - less than
< - equal to or less than
H - total of both horizontal vent lengths (Hr) and offsets (Ho) in feet
T
H - combined horizontal vent lengths in feet
R
H - offset factor: .03 (total degrees of offset - 90°*) in feet
O
H - offset factor: .03 (total degrees of offset - 135°*) in feet
O
V - combined vertical vent lengths in feet
T
3.5

elbow vent length values

Feet Inches
1° 0.03 0.5
15° 0.45 6.0
30° 0.9 11.0
45° 1.35 16.0
90°* 2.7 32.0
* The fi rst 90° offset has a zero value and is shown in the formula as - 90°
Top Exit
Vertical rise is less
than horizontal run
Horizontal run +
vertical rise to
maximum of
24.75 feet (7.5m)
4.2 times the vertical
rise equal to or
greater than the
horizontal run
Millimeters
12.7
152.4
279.4
406.4
812.8
venting requirements
Vertical Termination
Vertical rise is equal
to or greater than the
horizontal run
Horizontal run +
vertical rise to
maximum of
40 feet (12.2m)
EN
Vertical rise is less
than horizontal run
Horizontal run +
vertical rise to
maximum of
19 (5.8m)
3 times the vertical
rise equal to or
greater than the
horizontal run
17
W415-3035 / 05.04.21