5
General information
NOTE:Ifyouneedtoinstallducts,notethatthetotalduct
length of 3¼” x 10” rectangular or 6” diameter round duct
should not exceed 140 equivalent feet.
OutsideventilationrequiresaHOODEXHAUSTDUCT.
Readthefollowingcarefully.
NOTE: It is important that venting be installed using the
most direct route and with as few elbows as possible.
This ensures clear venting of exhaust and helps prevent
blockages. Also, make sure dampers swing freely and
nothing is blocking the ducts.
Exhaust connection:
The hood exhaust has been designed to mate with a
standard 3¼” x 10” rectangular duct.
Ifaroundductisrequired,arectangular-to-round
transition adaptor must be used. Do not use less than a
6” diameter duct.
Maximum duct length:
Forsatisfactoryairmovement,thetotalductlengthof3¼”
x 10” rectangular or 6” diameter round duct should not
exceed 140 equivalent feet.
Elbows, transitions, wall and roof caps, etc.,
present additional resistance to airflow and are equivalent
to a section of straight duct which is longer than their
actualphysicalsize.Whencalculatingthetotalduct
length,addtheequivalentlengthsofalltransitionsand
adaptors plus the length of all straight duct sections. The
chartbelowshowsyouhowtocalculatetotalequivalent
ductwork length using the approximate feet of equivalent
lengthofsometypicalducts.
DUCT PIECES
EQUIVALENT
LENGTH
x NUMBER USED =
EQUIVALENT
LENGTH
Rectangular-to-Round
Transition Adaptor*
5 ft. x () = ft.
WallCap 40 ft. x () = ft.
90° Elbow 10 ft. x () = ft.
45° Elbow 5 ft. x () = ft.
90° Elbow 25 ft. x () = ft.
45° Elbow 5 ft. x () = ft.
Roof Cap 24 ft. x () = ft.
Straight Duct 6” Round or
3¼” x 10” Rectangular
1 ft. x () = ft.
Total Ductwork = ft.
* IMPORTANT: If a rectangular-to-round transition
adaptorisused,thebottomcornersofthedamper
willhavetobecuttot,usingthetinsnips,in
order to allow free movement of the damper.
Equivalent lengths of duct pieces
are based on actual tests and reflect
requirements for good venting performance
withanyventhood.