Table of Contents
Advertisement
Available languages
Available languages
Calculate Total Equivalent Ductwork Length
Equivalent
Duct Pieces
Length* x
5" round
straight
2.7 ft.
6" round
straight
1 ft.
" x 10"
3
⁄
1
4
straight
1 ft.
5", 90°
elbow
37 ft.
6", 90°
elbow
12 ft.
5", 45°
elbow
18 ft.
6", 45°
elbow
7 ft.
Flexible
metal offset
See Calculations in
adapter
Step 5A.
" x 10"
3
⁄
1
4
90° elbow
14 ft.
" x 10"
3
1
⁄
4
45° elbow
8 ft.
" x 10"
3
1
⁄
4
90° flat elbow 33 ft.
5" round
" x 10"
to 3
1
⁄
4
transition
3 ft.
6" round
" x 10"
to 3
1
⁄
4
transition
2 ft.
Subtotal Column 1 =
*Equivalent lengths of duct pieces are based on
actual tests and reflect requirements for good
venting performance with any downdraft cooktop.
†Measure and list feet of straight duct used. Count
and list the quantity of all other duct pieces for
the "Number Used" of each type.
IMPORTANT:
For maximum efficiency, use the shortest and
straightest duct run possible, with as few fittings
as possible. For satisfactory performance, the duct
run should not exceed 100 feet equivalent length.
Venting performance is improved by using larger
diameter duct.
Installation Instructions
DUCTWORK CALCULATIONS
Number
Equivalent
Used =
Length
x
( ft.)
†
=
ft.
x
( ft.)
†
=
ft.
x
(
ft.)
†
=
ft.
x
(
) =
ft.
x
(
) =
ft.
x
(
) =
ft.
x
(
) =
ft.
ft.
x
(
) =
ft.
x
(
) =
ft.
x
(
) =
ft.
x
(
) =
ft.
x
(
) =
ft.
ft.
Duct Pieces
5" round
" x 10"
to 3
1
⁄
4
transition
90° elbow
6" round
" x 10"
to 3
⁄
1
4
transition
90° elbow
" x 10"
3
1
⁄
4
to 6" round
transition
" x 10"
3
⁄
1
4
to 6" round
transition
90° elbow
Tapered 5"
round to
6" round
transition
5" round collar
to 6" round
transition
5" round
wall cap
with damper
6" round
wall cap
with damper
" x 10"
3
1
⁄
4
wall cap
with damper
6" round
roof cap
If flexible metal ducting 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.
Vent installation should not exceed 100 feet
equivalent length.
Blower is rated at 400 CFM at 0.1 inch of
water back pressure.
18
Equivalent
Number
Equivalent
Length* x
Used =
Length
37 ft.
x
(
) =
4 ft.
x
(
) =
2 ft.
x
(
) =
4 ft.
x
(
) =
6 ft.
x
(
) =
13 ft.
x
(
) =
84 ft.
x
(
) =
24 ft.
x
(
) =
24 ft.
x
(
) =
33 ft.
x
(
) =
Subtotal Column 2 =
Subtotal Column 1 =
TOTAL DUCTWORK =
Should not exceed 100 feet.
ft.
ft.
ft.
ft.
ft.
ft.
ft.
ft.
ft.
ft.
ft.
ft.
ft.
Advertisement
Chapters
Table of Contents
