installation instructions

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Ducting Do’s and Don’ts

YES

Smooth Duct

Smooth Gradual Turn

Flexible Duct

Sharp Angled Turns

General Requirements

• Observe local codes regarding special duct requirements and placement of duct against combustibles.

• UsingVent-A-Hoodtransitions(backpage)willensurepropere󰀩ciency.

• UsingVent-A-Hoodroofjacksorwalllouvers(backpage)willensurepropere󰀩ciency.

• Where possible, seal joints with duct tape.

• The hood must be ducted to the outdoors without restrictions.

Blower Requirements

• The K250 blower unit requires 7” round duct or equivalent (32.5 square inches).

Blower Duct Dize Sq. Inch Area Vent-A-Hood Transition

K250 3 1/4" x 10" or equivalent 32.5 sq. in. VP521 (Optional)

Ducting Requirements

• NEVER reduce the duct size.

• Donotuseexibleorcorrugatedduct.Thistypeofductwillrestrictairowandreduceperformance.

• Onlyusesmooth,galvanized,metalduct.

• Make the duct run as short and as straight as possible with as few turns as possible.

• Avoid sharp-angled turns. Instead, use smooth, gradual turns such as adjustable elbows or 45 degree

angled turns.

• Forductrunsover20feet,increasetheductdiameterbyoneinchforeverytenfeetofduct.

• A 90 degree elbow is equal to 5 feet of duct.

Termination Requirements

• Airowmustnotberestrictedattheendoftheductrun.

• A wall louver or roof jack is required for each duct run.

• Everywalllouverorroofjackmustincludeagravitydampertopreventbackdrafts.

• Do not use screen wire or spring-loaded doors on wall louvers or roof jacks.

• Donotterminateventingintoanatticorchimney.