en-us_main.book.book Page 11 Thursday, March 21, 2024 12:57 PM
Ducting Calculation Sheet
Maximum duct length: For satisfactory air movement, the total duct length should not exceed 100
equivalent feet.
Duct pieces
3 1/4" x 10"
rect., straight
6" round,
straight
7"-10" round,
straight
3 1/4" x 10"
rect. 90°
elbow
3 1/4" x 10"
rect. 45°
elbow
3 1/4" x 10"
rect. 90° flat
elbow
3 1/4" x 10"
rect. wall cap
with damper
3 1/4" x 10"
rect. to 6"
round
transition
3 1/4" x 10"
rect. to 6"
round
transition 90°
elbow
6" round, 90°
elbow
6" Round,45°
elbow
Equivalent
length x
Total
number
used =
1 Ft. x ( ) =
Ft.
1 Ft. x ( ) =
Ft.
1 Ft. x ( ) =
Ft.
15 Ft. x ( ) =
Ft.
9 Ft. x ( ) =
Ft.
24 Ft. x ( ) =
Ft.
30 Ft. x ( ) =
Ft.
5 Ft. x ( ) =
Ft.
20 Ft. x ( ) =
Ft.
15 Ft. x ( ) =
Ft.
9 Ft. x ( ) =
Ft.
Subtotal
Ft.
column 1 =
INSTALLATION
Equivalent
length x
Duct pieces
number
used =
6" round wall
cap with
30 Ft. x ( ) =
damper
6" round, roof
30 Ft. x ( ) =
cap
6" round to 3
1/4" x 10" rect.
1 Ft. x ( ) =
transition
6" round to 3
1/4" x 10" rect.
16 Ft. x ( ) =
transition 90°
elbow
7"-10" round,
15 Ft. x ( ) =
90° elbow
7"-10" round,
9 Ft. x ( ) =
45° elbow
7"-10" round
wallcap with
30 Ft. x ( ) =
damper
7"-10" round,
30 Ft. x ( ) =
roof cap
7" round to 3
1/4" x 10" rect.
8 Ft. x ( ) =
transition
7" round to 3
1/4" x 10" rect.
23 Ft. x ( ) =
transition 90°
elbow
Subtotal
column 2 =
Subtotal
column 1 =
Total
ductwork =
11
Total
Ft.
Ft.
Ft.
Ft.
Ft.
Ft.
Ft.
Ft.
Ft.
Ft.
Ft.
Ft.
Ft.