Whirlpool RH8930XLS Manuale di istruzioni per l'installazione - Pagina 4
Sfoglia online o scarica il pdf Manuale di istruzioni per l'installazione per Cappa di ventilazione Whirlpool RH8930XLS. Whirlpool RH8930XLS 8. Vented kitchen range hood for 120 v. operation
Stampa la pagina
Guidellne
to Proper
Duct Sizing
for Ventllattng
An Indoor
Electric
Grill
These
Guidelines
are to insure
adequate
ventilation
for an
indoor
Electric
Grrll. Indoor
electric
grtlls produce
more smoke
than normal
cooking
and requrres
at least 410 CFM to provtde
adequate
ventrlation.
Less strmgent
ventilating
requirements
can devrate
from these recommendattons.
HORtZONTAL
VENTtNG
Figure
two on
page two shows
a direct
aischarge
to the
outside
through
a wall rain cap. Due to the lower CFM rating In
thus venting
posrtron,
duct must be limrted
la a maximum
of 2
feet of 3% x 10 inch duct capped
with a wall rain cap with a free
discharge
area of at least 66 inches square.
There should
be no
bends
in the connecting
duct between
the hood and the wall
rain cap.
Figure
9shows
an installation
requiring
more duct length. A
transrtion
to round
is used as close to the hood as possible
to
eliminate
the restriction
caused
by the 3% x 10 duct. 4S0 bends
should
be used instead
of 90° bends wherever
possrble.
VERTICAL
VENTING:
Figure one on page two shows an installation
using 3 feet of
3% x 10 inch duct termrnating
In a roof rain cap. In table one we
see that 3 feet of 3% x 10 inch duct is the maximum
length of 3% x
10 inch duct recommended.
For example,
if the straight
lengths
of duct In Fig 9 total 9 ft.
the elbow
is 45O and the roof rain cap has 113 In2 free area,
choose
the
duct
size
required.
The
45O elbow
can
be
approximated
by dtvtding
the equivalent
duct lengths
In Table 2
by two.
Since we already
have 9 ft. of straight
duct, Tdble 1 tells us that
7" dia. is too small. So we try 8" dia.
9 ft. Straight
Duct
6 ft. Equivalent
straight
length
of 4S0 elbow
(8" Dia.)
15 ft.
Fifteen
feet is over the maximum
of 13 ft. for 8" dia. duct, so 8"
duck is too small.
Move to 9" dia. duct and run through
the calculatrons
again.
9 ft. Straight
Duct,
7 ft. Equivalent
strarght
length
of 9" dia. duct for 45O elbow.
16 ft.
Sixteen
feet is under the maximum
of 25 ft. for 9" dia. duct, so 9"
duct is a good choice.
TABLE
I
Vertical
Venttnq
Table
I shows
the maxrmum
length
of duct to be
used In conjuncttan
with a roof ram cap having
a
free area of 113 inz.
TABLE
2
900
Elbow
Duct
Equivalent
length
of
Size
strarght
duct of same dia.
7" dia.
l*l ft.
0" dia.
12 ft.
9" dia.
14 ft.
10" dia.
16 ft.
CFM vs. DUCT
LENGTH
.25
355
26
61
104
.275
330
34
73
145
.30
250
65
136
.35
180
140
NOTE:
The above
table
is
based
on vertical
discharge.
The values
rn this table are for duct length only
and do not account
for static
pressure
loss through
roof mounted
ram caps.
Page
4