Installation guide
DUCT
PLANNING
GUIDE
Document
#
PGO6
-
001
cdacor.
The
Life
of
the
Kitchen?
7N
WARNING
Duct
Planning
Guide
All
blowers,
hoods
and
raised
vents
must
be
installed
in
accordance
with
the
accompanying
installation
instructions.
Observe
ail
governing
codes
and
ordinances
dunng
planning
and
installation.
Use
only
duct
work
deemed
acceptable
by
state,
municipal
and
local
codes
and
by
the
installation
instructions.
Contact
your
local
building
department
for
further
information.
To
prevent
combustion
by-products,
smoke
or
odors
from
entering
the
home
and
to
improve
efficiency,
tape
all
duct
joints
securely.
Hoods
and
vents
may
interrupt
the
proper
flow
of
smoke
and
combustion
gases
from
furnaces,
gas
water
heaters
and
fireplaces.
To
avoid
drawing
lethal
gases
into
the
home,
follow
the
manufacturer’s
recommendation
for
these
devices
and
consult
NFPA
and
ASHRAE
recommendations.
Improper
installation
may
result
in
a
back
draft
and/or
the
insufficient
venting
of
smoke
and
fumes.
For
hoods
or
raised
vents
equipped
with
integral
blowers,
DO
NOT
install
an
additional
in-line
or
external
blower
to
increase
the
length
of
the
duct
run.
For
hoods
or
raised
vents
not
equipped
with
integral
blowers,
DO
NOT
install
more
than
one
in-line
or
external
blower.
Even
small
differences
between
blower
air
flow
rates
can
greatly
reduce
the
air
draw.
To
reduce
the
risk
of
fire
and
to
properly
exhaust
air,
be
sure
to
duct
air
outside
the
house
or
building.
Do
not
vent
exhaust
air
into
spaces
within
wails
or
ceilings
or
into
attics,
crawl
spaces
or
garages.
General
Design
Requirements
All
duct
work
materials
(including
screws
and
duct
tape)
must
be
purchased
separately
by
the
customer
When
planning
new
duct
work,
always
look
for
the
shortest,
most
direct
route
to
the
outside
Some
models
can
accommodate
venting
(and/or
wiring)
through
the
back
To
prevent
a
back
draft,
never
decrease
the
duct
size
over
the run
If
existing
duct
work
is
smaller
than
8
inches
in
diameter,
remove
it
and
replace
it
with
8"
round,
10"
inch
round
or
3
1/4"
x
10"
duct
work
Do
not
use
duct
work
that
is
smaller
in
cross-sectional
area than
these
recommended
types
Do
not
use
flexible
metal
duct
Do
not
rely
on
tape
alone
to
seal
duct
joints
Fasten
all
connections
with
sheet
metal
screws
and
tape
all
joints
with
certified
silver
tape
or
duct tape
Use
sheet
metal
screws
as
required
to
support
the
duct
weight
Revised
10/21/09
Page
1/1
PLANNING
GUIDE
To
prevent
back-drafts,
a
damper
at
the
duct
outlet
may
also
be
required
Make
sure
duct
work
does
not
interfere
with
floor
joists
or
wall
studs
On
dual
exhaust
models,
the
two
8"
exhausts
may
be
merged
into
one
10"
duct
using
a
Dacor
transition
kit
See
the
installation
instructions
for
details
With
concrete
slab
construction,
"box-in"
the
duct
work
to
prevent
it
from
collapsing
when
the
wet
concrete
is
poured
Also
allow
room
for
electrical
conduit
Calculating
the
Maximum
Duct
Run
Length
The
maximum
straight
duct
length
is
determined
by the
type
of
hood
or
raised
vent
installed
and
type
of
duct
used
See
the
hood
or
raised
vent
specifications
for
the
maximum
duct
run
for
the
desired
configuration
To
determine
the
actual
length
the
duct
work cannot exceed,
subtract
all
of
the
equivalent
lengths
of
the
elbows
and
transitions
listed
below
from
the
maximum
straight
duct
run
from
the
hood/raised
vent
specifications
After
determining
that
your
proposed
duct
work
meets
the
maximum
duct
length
requirement,
proceed
with
the
location
planning
Equivalent
Lengths
Piece
Subtract
Piece
Subtract
8"
90°
elbow
7
feet
10"
90°
elbow
5
feet
8"
45°
elbow
3
feet
10"
45°
elbow
2
feet
3%"
X
10"
3%"
X
10"
to
to
round
25
feet
8"/10"
round
4
feet
90°
transition transition
3
t4"
X
10"
3
44"
X
10"
45°
elbow
‘feet
90°
elbow
19
feet
3
44"
X
10"
90°
flat
elbow
20
feet
Roof
cap
*
Wall
cap
with
*
damper
“The
equivalent
lengths
of
roof
and
wail
caps
vary
with
model
and
configuration
For
equivalent
length,
contact
the
manufacturer
or
a
qualified
HVAC
specialist
Duct
Work
Design
Tips
Wherever
possible,
reduce
the
number
of
transitions
and
turns
to
as
few
sharp
angles
as
possible
Two
staggered
45°
angles
are
better
than
one
90°
If
multiple
elbows
are
used,
try
to
keep
a
minimum
of
24"
straight
duct
between
them
Avoid
"S"
or
“back
to
back"
use
of
adjacent
elbows
Keep
turns
as
far
away
from
the
hood
or
raised
vent
exhaust
as
possible,
and
as
much
space
between
bends
as
possible
For
best
performance,
use
round
duct
instead
of
rectangular,
especially
when
elbows
are
required
Cross-drafts
or
air
currents
caused
by
adjacent
open
windows
or
doors,
HVAC
outlets,
ceiling
fans
and
recessed
ceiling
lights
reduce
vent
efficiency
www.Dacorcom
Phone:
(800)
793-0093
Specifications
are
subject
to
change
without
notice.
See
installation
instructions
for
additional
details.
6.1