Venting Methods - Jenn-Air CVEX4100B Instructions Manual

Use only a 6" (15.2 cm) round metal vent or a 3 " x 10"
(8.3 x 25.4 cm) rectangular metal vent except for as follows:
For electric models, 5" (12.7 cm) diameter round metal
vent may be used for venting straight out the back of the
cooktop and directly through the wall for a duct length of
10 ft (3.0 m) feet or less.
For gas models, 5" (12.7 cm) diameter round metal vent
must be used if the duct length is 10 ft (3.0 m) feet or less.
Do not use 5" (12.7 cm) elbows except in a 5" (12.7 cm)
system. Instead, use a 5" (12.7 cm) to 6" (15.2 cm) elbow or a
5" (12.7 cm) to 3 " x 10" (8.3 x 25.4 cm) elbow transition.
Use vent clamps to seal all joints in the vent system.
Use caulking to seal exterior wall or roof opening around the
cap.
Determine which venting method is best for your application.
For Best Performance:
Use 26-gauge minimum galvanized or 25-gauge minimum
aluminum metal vent. Poor quality pipe fittings can reduce
airflow. Flexible metal vent is not recommended.
NOTE: Local codes may require a heavier gauge material.
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).
Do not install 2 elbows together.
Use no more than three 90° elbows.
If an elbow is used, install it as far away as possible from the
hood's vent motor exhaust opening.
Make sure there is a minimum of 18" (45.7 cm) of straight
vent between the elbows if more than one elbow is used.
Elbows too close together can cause excess turbulence that
reduces airflow.
Do not use a 5" (12.7 cm) elbow in a 6" (15.2 cm) or 3 " x 10"
(8.3 x 25.4 cm) system.
Do not reduce to a 5" (12.7 cm) system after using
6" (15.2 cm) or 3 " x 10" (8.3 x 25.4 cm) fittings.
Avoid forming handmade crimps. Handmade crimps may
restrict airflow.
Use a Jenn-Air ® 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 back draft damper.
The length of vent system and number of elbows should be kept
to a minimum to provide efficient performance.
The maximum equivalent length of the vent system is 60 ft
(18.3 m). For altitudes above 4,500 ft (1272 m), reduce
recommended vent run by 20% for best performance.
Cold Weather Installations
An additional back draft damper should be installed to minimize
backward cold air flow and a thermal break installed to minimize
conduction of outside temperatures as part of the vent system.
The damper should be on the cold air side of the thermal break.
Makeup Air
Local building codes may require the use of makeup air systems
when using ventilation systems greater than specified CFM of air
movement. The specified CFM varies from locale to locale.
Consult your HVAC professional for specific 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 floor.
Option 1 - Roof Venting
B
A
A. 6" (15.2 cm) round roof
venting
B. Roof cap
Option 3 - Venting Between
Floor Joist
B
A
A. Wall cap
B. 6" (15.2 cm) round wall
venting
Option 2 - Wall Venting
B
A
A. 6" (15.2 cm) round wall
venting
B. Wall cap
Option 4 - Venting behind
Cabinet Kick Plate
B
A
A. Wall cap
B. 6" (15.2 cm) round wall
venting
5