Heatilator • GDST4336I, GDFL4136I, GDCR4136I, GDCL4136I • 2129-900 Rev. F • 11/08 27
To replace the fi rst starter elbow with two 45° elbows,
refer to Figure 7.3. 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. 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
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
Top Vent—Horizontal Termination—Two 45° Elbows
Installation requirements to replace the fi rst 90° elbow with two 45° elbows:
4 ft min.
(1.22 m)
16 ft max.
(4.87 m)
Figure 7.3 Minimum Installation Requirements for Two 45° Elbows-Top Vent-Horizontal Termination
Note: The Multi-Sided series fi replaces can adapt to SLP series vent pipe, if desired.
When venting off the top of the unit, attach a DVP-2SL adapter to
the appliance starting collar, immediately followed by a minimum
48 inch vertical section of SLP series vent pipe.
After the 48 inch vertical section, the venting table rules
must be followed. The fi rst 48 inch vertical section is NOT
counted as part of the vertical components in the table. It is
still counted as part of the overall maximum run. All venting
table rules for the vent run must still be followed.
Example:
DVP pipe 3 ft. min. vertical = 11 ft. max. horizontal
SLP pipe 7 ft. min. vertical = 11 ft. max. horizontal
Note: Reference Figure 7.14 for
special instructions for use of 45º
elbow on rear vent appliances.