Heatilator • Novus NDV Series • 4055-187 Rev F • 06/0824
To replace the fi rst starter elbow with two 45° elbows, refer
to Figure 7.4. All other 90° elbows can be replaced with
two 45° elbows.
General Rules:
• SUBTRACT 3 ft. from the total H measurement for each
90° elbow installed horizontally.
• SUBTRACT 1-1/2 ft. from the total H measurement for
each 45° elbow installed horizontally.
• A maximum of three 90° elbows (or six 45° elbows) may
be used in any vent confi guration. Some elbows may be
installed horizontally.
• Elbows may be placed back to back anywhere in the
system as long as the fi rst 90° elbow is a starter elbow
except as shown in Figure 7.3.
• When penetrating a combustible wall, a wall shield
fi restop must be installed.
• When penetrating a combustible ceiling, a ceiling fi restop
must be installed.
• Horizontal runs of vent do not require vertical rise;
horizontal runs may be level.
E. Vent Diagrams
Two 45° Elbows
Installation requirements to replace the fi rst 90° elbow
with two 45° elbows:
4 ft min.
(1.22 m)
25 ft max.
(7.62 m)
Figure 7.3 Minimum Installation Requirements for Two 45°
Elbows-Top Vent-Horizontal Termination
1. Top Vent - Horizontal Termination
Note: The NDV series appliances can adapt to SLP series
vent pipe when venting off the top of the appliance. You
must use a DVP-SLP24 adapter which can only be attached
to the appliance starting collar.
When looking at horizontal termination diagrams, the
adapter is not counted as part of the minimum vertical
(V
1
min.) requirements.
Whether horizontal or vertical termination, the adapter is
counted as part of the maximum vertical limitations.
All venting rules for the vent run must still be followed.
H
1
= 11 ft.
max.
V
1
= 1 ft.
DVP-SLP24
H
1
= 11 ft.
max
V
1
= 1 ft.
DVP
HORIZONTAL EXAMPLE
SLP
12 ft (3.66 m) min.
60 ft (18.29 m) max.
12 ft (3.66 m) min.
60 ft (18.29 m) max.
DVP
VERTICAL EXAMPLE
SLP
DVP-SLP24
Adapter
Î