Installation instructions

• The hood exhaust connects to an 8-inch round duct.

You can increase the duct size over the duct run if

desired.

• To prevent a backdraft, never decrease the duct size

over the run. If existing ductwork is smaller than 8

inches in diameter, remove it and replace it with 8-inch

ductwork.

• Do not rely on tape alone to seal duct joints. Fasten

all connections with sheet metal screws, and tape all

joints with certified duct tape or foil tape.

• Use sheet metal screws as needed to support the

weight of the ducting.

• To prevent backdrafts, a damper at the duct outlet may

also be required.

Preparation and Setup

Ductwork Tips

Wherever possible, reduce the number of transitions, turns,

and sharp angles. Two staggered 45° angles are better

than one sharp 90° angle.

Keep turns as far away from the hood exhaust as possible,

and keep as much space between any bends as possible.

For best performance: use round duct instead of rectangu-

lar, especially when elbows are required.

If multiple elbows are used, try to keep at least 24 inches of

straight duct between each elbow.

Avoid using “S” or back-to-back adjacent elbows.

In extremely cold weather regions, use thermal breaks, i.e.,

short sections of non-metallic duct, to avoid indoor heat

loss. Locate the break as close as possible to the outside

pass-through point.

Do not use flexible metal duct. Do not use ductwork that is

smaller than what is advised in the tables.