1-4
VENTING REQUIREMENTS
WARNING
Fire Hazard
The venting system must terminate outdoors.
Do not end the ductwork in an attic, wall,
ceiling, or other enclosed space.
Do not use 4
"
laundry-type wall caps.
Do not use plastic duct.
Do not block the flow of ventilation air.
Failure to follow these instructions could
result in a fire.
For the quietest and most efficient operation:
•
Use 26-gauge minimum galvanized, or 25-
gauge minimum, aluminum metal duct.
Poor-quality pipe fittings can reduce air
flow. (Note: Local codes may require a
heavier-gauge material.) Flexible metal
duct is not recommended.
•
Do not exhaust more than one downdraft
cooktop into a single duct system.
•
Keep the length of duct and number of
elbows to a minimum.
•
Keep the size of the duct uniform.
•
Use no more than three 90˚ elbows.
•
Do not install two elbows together.
•
If more than one elbow is used, make sure
that there is a minimum of 18
"
(45.7 cm) of
straight duct between them. If elbows are
too close together, they can reduce air-
flow.
•
Do not use a 5
"
elbow in a 6
"
, or a 3-
1
/
4
"
x10
"
system. Use a 5
"
to 6
"
transition fol-
lowed by a 6
"
elbow, or a 5
"
to 3-
1
/
4
"
x10
"
elbow transition.
•
Do not reduce the duct work back to a 5
"
system after using 6
",
or 3-
1
/
4
"
x10
"
fit-
tings.
•
Do not form handmade crimps. They can
restrict airflow.
•
Use recommended duct caps. If an alter-
nate wall, or roof cap is used, be certain
that the cap size is not reduced, and that it
has a backdraft damper.
•
Use duct tape to seal all joints in the duct
system.
•
Use weatherproof caulking to seal the ex-
terior wall or roof opening around the cap.
Before making any cutouts, make sure that
there is proper clearance within the wall or
floor for the exhaust duct. Do not cut a joist
or stud unless it is absolutely necessary. If
a joist or stud must be cut, a supporting
frame must be constructed.
This downdraft cooktop is rated for 60-feet of
straight duct. If duct length is 10 feet (3 m) or
less, 5
"
diameter round ductwork may be used.
If duct length is more than 10 feet (3 m), use 6
"
diameter round or 3-
1
/
4
"
x 10
"
rectangular duct.
Thermal Breaks:
In areas of extreme cold
weather, it may be necessary to provide a
short length of nonmetallic duct as close to the
wall as possible to prevent thermal conduction
along the metal duct.
High Altitudes:
For altitudes above 4,500 ft
(1,350 m), reduce the recommended duct run
by 20%.
