7
Venting Requirements
IMPORTANT:
This range must be exhausted outdoors unless
you are using ductless venting. See the “Venting Methods”
section.
■
Do not terminate the vent system in an attic or other
enclosed area.
■
Use an approved 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.
■
Vent system must terminate to the outside unless you are
using a ductless vent kit.
■
Use a 5" (12.7 cm) or 6" (15.2 cm) round metal vent
or a 3¼" x 10" (8.3 cm x 25.4 cm) rectangular vent.
■
Rigid metal vent is recommended. For best performance,
do not use plastic or metal foil vent.
■
If a joist or stud must be cut, then a supporting frame must
be constructed.
■
The size of the vent should be uniform.
■
The vent system must have a damper.
■
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. For external venting, flexible metal vent is not
recommended.
NOTES:
■
For external venting, flexible metal vent is not
recommended. Flexible vent creates back pressure
and air turbulence that greatly reduce performance.
■
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).
■
Avoid installing 2 elbows together.
■
Use no more than three 90° elbows.
■
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 3¼" x 10" (8.3 x 25.4 cm) system.
■
Do not reduce to a 5" (12.7 cm) system after using
a 6" (15.2 cm) or 3¼" x 10" (8.3 x 25.4 cm) fittings.
■
Avoid forming handmade crimps. Handmade crimps
may restrict airflow.
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 backdraft 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.
Order Part Number 708786A for a 5" (12.7 cm) thermal break.
Order Part Number 715557A for a 6" (15.2 cm) thermal break.
To order, see the “Assistance or Service” section of the Use
and Care Guide.
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 downdraft range.
The downdraft range may be vented through the wall or floor.
Wall Venting
Floor Venting
Venting Between Floor Joists
A. Wall cap
B. Venting
A
B
A
B
A. Wall cap
B. Venting
