HOOD EXHAUST DUCT
Outside ventilation requires HOOD EXHAUST DUCT. Read the following carefully.
EXHAUST CONNECTION: The hood exhaust has been designed to mate with a standard
3-x” x 10” rectangular duct.
If round duct is required, a rectangular-to-round transition adaptor must be used. DO not use
less than a 6” diameter duct.
REAR EXHAUST: If rear or horizontal exhaust is to be used, care should be taken to align ex-
haust with space between studs, or wall should be prepared at the time it is constructed by leav-
ing enough space between wall studs to accommodate exhaust.
MAXIMUM DUCT LENGTH: For satisfactory air movement, the total duct length.of 3-x” x 10”
rectangular or 6” diameter round duct should not exceed 140 feet.
ELBOWS, TRANSITIONS, WALL and ROOF CAPS, etc. present additional resistance to air flow and are
equivalent to a section of straight duct which is longer than their actual physical size. When calculating
the total duct length add the equivalent lengths of all transitions and adaptors plus the lengths of all
straight duct sections. The diagram below shows the approximate feet of equivalent length of some
typical ducts.
EXHAUST DUCT
@a
90° ELBOW
10 FT.
10” WIDE ELBOW
10 FT.
WALL CAP
40 FT.
45O ELBOW
TRANSITION ADAPTOR
5 FT. 5 FT.
90’ ELBOW
I
4.5O ELBOW
I
25 FT.
5 FT.
1
I
ROOF CAP
24 FT.
6