Table 1. ventilator performance calculation – Thermador HMWB36 User Manual
Page 7

e
c
e
i
P
t
c
u
D
10" round
to 8" roun d
5 ft.
Round ,
1 ft.
straight
(per foot
length)
3-1/4" x 10"
1 ft.
3-1/4" x 12 "
(p er f oot
straight
length)
8" Di a. 17 ft.
90
° elbow
10" Dia. 24 ft .
8" Di a. 10 ft.
45
° elbow
10" Dia. 14 ft .
3 -1⁄4" x 12"
15 ft.
3-1/4" x 10"
14 ft.
90
° elbow
3-1/4" x 10 "
8 ft.
3-1/4" x 12 "
9 ft.
45
° elbow
3-1/4" x 10"
33 ft.
3-1/4" x 12"
36 ft.
90
° flat elbow
10" round transition
to 3-1/4" x 10" or
3-1/ 4" x 12"
9 ft.
3-1/4" x 10" or
3-1/4" x 12" to
10" round transiti on
6 ft.
10" round to 3-1/4" x 10"
16 ft.
3-1/4" x 12" transiti on
13 ft.
90
° elbow
3-1/4" x 10 "
9 ft.
3-1/4" x 12" t o 10" round
8 ft.
transiti on 90
° elbow
Roun d
8" Dia. 32 ft.
wall c ap
10" Dia. 41 ft.
with damper
3-1/4" x 10"
24 ft.
3-1/4" x 12" wall cap
26 ft.
with damper
Round
8" Dia. 44 ft.
roof c ap
10" Di a. 56 ft .
Us e this chart to compute maximum
permissable lengths for duct runs to
outdoors .
Note: Do not exceed maximum permissable
equivalent lengths!
Maximum recommended duct
length for these hoods: 150 feet
Fl exible ducting:
If flexible metal duct ing is used, all
the equivalent feet values in the table
should be doubled. The flexible
metal duct should be straight and
smooth and extended as much as
possible.
Do NOT use flexible plastic ducting.
Total Duct Run
Note:
Any home ventilation system, such as a
gas furnaces, gas water heaters and other naturally
vented systems. To minimize the chance of interruption
of such naturally vented systems, follow the heating
equipment manufacturer’s guidelines and safety
standards such as those published by NFPA and ASHRAE.
*Hoods are supplied with a 10"
round transition. A locally
supplied transition is required
for other sizes.
Note: Outlet on top of hood is
8-1/8" x 8".
Table 1. Ventilator performance calculation
7