13
EN
W415-1541 / C / 11.23.17
3.3 special vent installations
3.3.1 periscope termination
Use the periscope kit to locate the air termination above grade. The periscope must be installed so that
when fi nal grading is completed, the bottom air slot is located a minimum 12” (30.5cm) above grade.
The maximum allowable vent length is 10’ (3.1m).
9.4B
30”
MINIMUM
12”
MINIMUM
TOP EXIT INSTALLATION
REAR EXIT INSTALLATION
30”
MINIMUM
12”
MINIMUM
MAXIMUM 10FT VENT LENGTH
6” (152mm)
RISE MINIMUM
20” (50.8cm)
MAXIMUM
20” (50.8cm)
MAXIMUM
30”
MINIMUM
12”
MINIMUM
TOP EXIT INSTALLATION
REAR EXIT INSTALLATION
30”
MINIMUM
12”
MINIMUM
MAXIMUM 10FT VENT LENGTH
6” (152mm)
RISE MINIMUM
20” (50.8cm)
MAXIMUM
20” (50.8cm)
MAXIMUM
3.3.2 corner termination
12" (30.5cm)
minimum
to grade
12" (30.5cm)
minimum
to grade
30" (76.2cm)
minimum
30" (76.2cm)
minimum
34 5/8"
(87.9cm)
The maximum vent length for a corner installation is 20" (508mm) of horizontal run, in addition to the 45°
offset. Using rigid venting, zero rise is acceptable. Using flexible venting, it is required to maintain a 6"(152mm)
rise. See illustrations below.
Flex Venting
Rigid Venting
