GE CVM2072 Installation Instructions Manual page 5

Installation Instructions
NOTE: If wm need to install ducts, note that the total
duct lengti_ of 3¼" x ] O" rectangular or 6" diameter
round duct should not exceed 140 equivalent feet.
Outside ventilation requires a HOOD EXHAUST DUCT.
Read the following careflfllv.
NOTE: It is important that venting be installed using
the most direct route and with as few elbows as possible.
This ensm'es clear venting of exhaust and helps prevent
blockages. Also, make sure dmnpers swing freely and
nothing is blocking the ducts.
Exhaust connection:
The hood exhaust has been designed to mate with
a standard 3Vt" x 10" rectangular duct.
If a round duct is required, a rectangula_to-rotmd
transition adaptor inust be used. Do not use less than
a 6" diameter duct.
Maximum duct length:
For satisfiwtorv air movement, the total duct length of
3¼" x ] 0" 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
equiwdent to a section of straight duct which is longer
than their actual physical size. When calculating the total
duct length, add the equiwdent lengths of all transitions
and adaptors plus the length of all straight duct sections.
The chart below shows w)u how to calculate total
equivalent ductwork length using the approximate feet
of equiwdent length of some typical ducts.
EQUIVALENT NUMBER EQUIVALENT
DUCT PIECES LENGTH x USED = LENGTH
Rectangular-to-Round 5 Ft. x ( ) = Ft.
TransitionAdaptor*
..,,..,,.-%
Wall Cap 40 Ft. x ( ) = Ft.
()_ 90 ° Elbow 10 Ft. x ( ) = Ft.
45° Elbow 5 Ft. x ( ) = Ft.
90 ° Elbow 25 Ft. x ( ) = Ft.
J 45° Elbow 5Ft. x ( ) = Ft.
RoofCap 24 Ft. x ( ) = Ft.
StraightDuct6" Roundor 1 Ft. x ( ) = Ft.
3W' x 10" Rectangular
Total Ductwork
=
Ft.
* IMPORTANT: If a r_( tangulal_to-round transilion Equival< nl 1_ngths o[ du_t pie_<s are bas<d on aclual lests
adaptor is used, the bottom comers of th( dampel and ret]ect requiremenls tk)r good venling performanc( with
xdll hax< to b< Clll to fit, using Ih(t lill snips, in ordel any vent hood.
to allm_ free lllOVelllelll of Ihe
(]alllpel.
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