Hearth and Home Technologies GDST3831I - Manual (Page 26)

Heatilator • GDST3831I • 2127-900 Rev. F • 10/08 26
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. See Figure 7.6.
• Elbows may be placed back to back anywhere in the
system as long as the fi rst 90° elbow is a starter elbow.
• 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.
F. Vent Diagrams
H
1
V
1
Figure 7.4
One Elbow
1. Top Vent - Horizontal Termination
V
1
Minimum** H
1
Maximum
90 Elbow** 2 ft. 610 mm
1/2 ft.** 152 mm 2 ft. 610 mm
1-1/2 ft.** 457 mm 3 ft. 914 mm
2-1/2 ft.** 762 mm 5 ft. 1.5 m
3-1/2 ft. 1.1 m 7 ft. 2.1 m
4-1/2 ft. 1.4 m 14 ft. 4.3 m
H
1
Max. =14 ft. (4.3 m)
V + H Max. = 40 ft. (12.2 m)
See Warning**
WARNING**
Note: There MUST be a 25%
reduction in total H when using
fl ex vent except when using the
simple up and out installation
(see Figure 7.3).
Fire Risk.
• When using SLP-HRC-SS and SLP-HRC-ZC-SS
termination caps on top vented fi replaces, a one
foot minimum vertical vent section is required before
installing fi rst elbow .
• When using DVP-TB1 termination cap on top vented
fi replaces, a three foot minimum vertical vent section
is required before installing fi rst elbow.
• When using any other cap, a section of vertical pipe (12 inches
minimum) MUST be installed prior to attaching a 90° elbow.