Reference Guides PDF

PLANNING
GUIDE
Web: http://www.Dacor.com
Corporate Phone: [phone]
Specifications are subject to change without notice.
See installation instructions for additional details.
6.1
Duct Planning
DUCT PLANNING
WARNINGS:
1. To reduce the risk of fire and to properly exhaust
air, ducted fans must be vented to outside. Do not
vent exhaust air into spaces within walls, ceilings,
attics, crawl spaces or garages.
2. Improper installation, adjustment, alteration,
service or maintenance can cause personal injury
or property damage
3. To reduce the risk of fire, use only ductwork
materials deemed acceptable by state, municipal
and local codes.
NOTES:
1. Best performance is achieved by using round duct
instead of rectangular, especially when elbows are
required.
2. If multiple elbows are needed, ensure that there is
a minimum of 24”of straight duct between any two
elbows.
3. Avoid “S” or “back to back” configurations caused
by adjacent elbows.
4. Thermal breaks, such as a short section of non-
metallic duct, should be used in areas of extreme
cold.
5. A back-draft damper at the duct outlet may also be
required.
6. Do not use flexible metal duct.
7. Do not use ductwork that is smaller in cross-
sectional area than the recommended size duct.
8. Do not rely on duct tape alone to seal duct joints.
Use sheet metal screws as required to support the
duct weight.
9. The vent hood and cooking appliance(s) must be
removable if service is required.
10. Be certain that the ductwork does not interfere with
floor joists or wall studs.
11. It is important to keep as few turns in the duct run,
and to keep the run as short as possible.
12. Do not restrict the air flow by reducing the duct
cross-sectional areas when making hard joints or
squeezing through a tight area.
Higher volumes of air exhausted by the vent system result in better
overall removal of smoke and fumes from the kitchen. Longer duct runs
and greater numbers of duct transitions reduce air volume, therefore it
is extremely important to keep duct runs as short and straight as
possible.
To ensure that your installation meets this requirement, add the actual
straight length of duct to the equivalent straight length of all duct fittings to
determine the total equivalent straight length of duct. (Refer to the table
below. Consider the duct size that corresponds to the majority of the duct
used in the installation.
After determining that your proposed ductwork meets the maximum duct
length requirement, proceed with the location planning.
Equivalent Straight Feet
90° Elbow, 3 1/4” x 10” 15 ft.
90° Elbow, 8” Round 7 ft.
90° Elbow, 10” Round 5 ft.
45° Elbow, 3 1/4” x 10” 7 ft.
45° Elbow, 8” Round 3 ft.
45° Elbow, 10” Round 2 ft.
Straight Transition, 3 1/4” x 10” to 8” Round 4 ft.
Straight Transition, 3 1/4” x 10” to 10” Round 4 ft.
90° Transition, 3 1/4” x 10” to 8” Round 25 ft.
90° Transition, 3 1/4” x 10” to 10” Round 25 ft.
1/1
PLANNING
GUIDE
Revised
02/04/08
13. With concrete slab construction, "box-in" the
ductwork to prevent it from collapsing when
the wet concrete is poured. Also allow room for
electrical conduit.
14. Cross-drafts or air currents caused by adjacent
open windows or doors, HVAC outlets, ceiling fans
and recessed ceiling lights reduce vent efficiency.