GE SCB1000 Installation Instructions Manual page 5

Installation Instructions
NOTE: If wm need to install ducts, note that the total duct
length of 3¼" x ] 0" rectangular or 6" dianmter round duct
should not exceed 140 equivalent feet.
Outside ventilation requires a HOOD EXHAUST DUCT.
Read the following careflflly.
NOTE: It is important that venting be installed using
the most direct route and with as tew elbows as possible.
This ensures clear venting of exhaust and helps prevent
blockages. Also, lllaJ_e sure dmnpers 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,
If a r(mnd duct is required, a rectangula>to-rom_d
transition adaptor must be used. Do not use less thml
a 6" diameter duct.
Maximum duct length:
For satisfi_ctory air movement, the total duct length of
3/(' 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 equi\_flent
to a section ol straight duct which is longer than their actual
ph):sical size. When calculating the total duct length, add
the equivalent lengths of all transitions and adapt(n_ plus
the length ot all straight duct sections. The chart below
sho_vs you how to calculate total equi\;flent ductwork length
using the approximate teet ol equivalent length ol some
Q'pical ducts.
EQUIVALENT NUMBER EQUIVALENT
DUCT PIECES LENGTH x USED = LENGTH
Rectangular-to-Round 5 Ft. x ( ) = Ft.
TransitionAdaptor*
Wall Cap 40 Ft. x ( ) = Ft.
G)_ 90° Elbow 10 Ft. x ( ) = Ft.
(_ 45° Elbow 5 Ft. x ( ) = Ft.
90° Elbow 25 Ft. x ( ) = Ft.
45° Elbow 5 Ft. x ( ) = Ft.
RoofCap 24 Ft. x ( ) = Ft.
Straight Duct6" Roundor 1 Ft. x ( ) = Ft.
3W' x 10" Rectangular
Total Ductwork = Ft.
* IMPORTANT: If' a rectangular-to-round transition adaI)mr
is used, the bottom comers of the dami)er will ha_e to be
cut to fit, using Ihe tin snips, in order to allow fi-ee moxenlent
of the damper.
Equivalent lengths of duct pi< c<s at< based on actual t<sts
and r( flect re(luir( merits for good venting l)( rlormance
with
_]I]V V(}llt hoo([.
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