Dacor PHW Electrical Power Supply, Plan the Duct Work Installation, Duct Piece Subtract

Preparing for Installation

Electrical Power Supply

WARNING

•Observe all governing codes and ordinances during planning and installation. Contact your local building department for further information.

Electrical Specifications

It is the owner’s responsibility to ensure that the electrical connection of this appliance is performed by a qualified electrician. The electrical installation, including minimum supply wire size and grounding, must be in accordance with the National Electric code ANSI/NFPA* (or latest revision) and local codes and ordinances.

*A copy of the standard may be obtained from:

National Fire Protection Association 1 Batterymarch Park

Quincy, Massachusetts 02269-9101

This hood requires a dedicated 120 Vac, 60Hz, 15 A circuit.

Plan the Duct Work Installation

WARNING

•To reduce the risk of fire and to properly exhaust air, be sure to duct air outside the house or building. Do not vent exhaust air into spaces within walls or ceilings or into attics, crawl spaces or garages.

•Tape all duct joints securely to prevent combustion by-products, smoke or odors from entering the home. Doing so will also improve system efficiency.

•Do not exhaust more than one vent into a single duct run.

•Use only duct work constructed of materials deemed acceptable by state, municipal and local codes.

•Range hoods may interrupt the proper flow of smoke and combustion gases from furnaces, gas water heaters and fireplaces. To avoid drawing lethal gases into the home, follow the manufactures recommendation for these devices and consult NFPA and ASHRAE recommendations.

•All duct work materials (including screws and duct tape) must be purchased separately by the customer.

•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 back draft, never decrease the duct size over the run.

•Do not rely on duct tape alone to seal duct joints. Fasten all connections with sheet metal screws and tape all joints with certified silver tape or duct tape. Use sheet metal screws as require to support the duct weight.

•To prevent back-drafts, a

damper at the duct outlet may also be required.

•When planning new duct

work, always look for the shortest, most direct route to the outside. Venting can be done through the roof or directly through the back wall to the outside.

•Make sure duct work

does not interfere with floor joists or wall studs.

Calculating the Maximum Duct Run Length

The maximum straight duct length for the hood is 100 feet. For each elbow and transition added to the duct work, a certain number of feet must be subtracted from the maximum straight length to compensate for wind resistance. To determine the length the duct work cannot exceed, subtract all of the equivalent lengths of the elbows and transitions listed below from 100 feet.

Duct Work Equivalent Lengths

DUCT PIECE	SUBTRACT
90° elbow	15 feet
45° elbow	9 feet
3 1/4” x 10” to 8” round	1 foot
Wall cap with damper	30 feet
Roof cap	30 feet

Duct Work Design Tips

•Wherever possible, reduce the number of transitions and turns to as few sharp angles as possible. Two staggered 45° angles are better than one 90°. Keep turns as far away from the hood exhaust as possible, with as much space between each bend as possible.

•For best performance, use round duct instead of rectangular, especially when elbows are required.

•If multiple elbows are used, try to keep a minimum of 24” of straight duct between them. Avoid “S” or “back to back” configurations of adjacent elbows.

•In regions where the weather gets extremely cold, thermal breaks, such as a short section of non-metallic duct, should be used to avoid indoor heat loss. The break should be located as close to the pass through point to the outside as possible.

•Do not use flexible metal duct.

•Do not use duct work that is smaller in cross-sectional area than the recommended size duct (8” round).