Installation Instructions

5
For Best Performance:
n Use 26-gauge minimum galvanized or 25-gauge minimum
aluminum metal vent. Poor quality pipe ttings can reduce
airow. Flexible metal vent is not recommended.
NOTE: Local codes may require a heavier gauge material.
n Metal duct may be reduced to 30-gauge galvanized steel
or 26-gauge aluminized steel if allowed by local codes.
This reduction is based on information in the International
Residential Codes Section M1601.1 (2006 edition).
n Do not install 2 elbows together.
n Use no more than three 90° elbows.
n If an elbow is used, install it as far away as possible from
thevent motor exhaust opening.
n Make sure there is a minimum of 18" (45.7 cm) of straight
vent between the elbows if more than one elbow is used.
n Elbows too close together can cause excess turbulence that
reduces airow.
n Do not use a 5" (12.7 cm) elbow in a 6" (15.2 cm) or 3
1
/
4
" x 10"
(8.3 cm x 25.4 cm) system.
n Do not reduce to a 5" (12.7 cm) system after using
6" (15.2 cm) or 3
1
/
4
" x 10" (8.3 cm x 25.4 cm) ttings.
n Avoid forming handmade crimps. Handmade crimps may
restrict airow.
n Use a vent cap for proper performance. If an alternate wall
or roof cap is used, be certain the cap size is not reduced
and that it has a backdraft damper.
n Use vent clamps to seal all joints in the vent system.
n Use caulking to seal exterior wall or roof opening around
the cap.
The length of vent system and number of elbows should be kept
to a minimum to provide efcient performance.
The maximum equivalent length of the vent system is 60 ft
(18.3 m). For altitudes above 4,500 ft (1372 m), reduce
recommended vent run by 20% for best performance.
Cold Weather Installations
An additional backdraft damper should be installed to minimize
backward cold air ow.
Makeup Air
Local building codes may require the use of makeup air systems
when using ventilation systems greater than specied CFM of
air movement. The specied CFM varies from locale to locale.
Consult your HVAC professional for specic requirements in
your area.
Venting Methods
Common venting methods are shown for a counter-mounted
downdraft cooktop. The cooktop may be vented through the
wall or oor.
Option 1 - Roof Venting Option 2 - Wall Venting
A
B
A
B
A. 6" (15.2 cm) round roof venting
B. Roof cap
A. 6" (15.2 cm) round wall venting
B. Wall cap
Option 3 - Venting
Between Floor Joist
Option 4 - Venting Behind
Cabinet Kick Plate
A
B
A B
3¼" x 10"
(8.3 cm x 25.4 cm)
A. Wall cap
B. 6" (15.2 cm) round wall venting
A. Wall cap
B. 6" (15.2 cm) round wall venting