Filter
Top Products
5
Duct pieces
To t a l
Equivalent number
length x used =
3- 1/ 4” x 10”
Rect.,
straight
1 Ft. x ( ) =
Ft.
8” Round,
straight
1 Ft. x ( ) =
Ft.
3- 1/ 4” x 10”
Rect. 90
0
elbow
15 Ft. x ( ) =
Ft.
3- 1/ 4” x 10”
Rect. 45
0
elbow
9 Ft. x ( ) =
Ft.
3- 1/ 4” x 10”
Rect. 90
0
flat elbow
24 Ft. x ( ) =
Ft.
3- 1/ 4” x 10”
Rect.
wall cap
with damper
30 Ft. x ( ) =
Ft.
3- 1/ 4” x 10”
Rect. to
6” round
transition
5 Ft. x ( ) =
Ft.
3- 1/ 4” x 10”
Rect. to
6” round
transition
90
0
elbow
20 Ft. x ( ) =
Ft.
6” Round,
90
0
elbow
15 Ft. x ( ) =
Ft.
6” Round,
45
0
elbow
9 Ft. x ( ) =
Ft.
Ft.
7” Round,
straight
1 Ft. x ( ) =
Ft.
Subtotal column 1 =
Duct pieces
To t a l
Equivalent number
length x used =
6”- 8” Round
wall cap
with damper
30 Ft. x ( ) =
Ft.
Round
wall cap
with damper
30 Ft. x ( ) =
Ft.
7” or 8”
Round,
90
0
elbow
15 Ft. x ( ) =
Ft.
7” or 8”
7” or 8”
Round,
45
0
elbow
9 Ft. x ( ) =
Ft.
Ft.
Ft.
Ft.
6”- 8” Round,
roof cap
30 Ft. x ( ) =
Ft.
7” or 8”
Round,
roof cap
30 Ft. x ( ) =
Ft.
Subtotal column 2 =
Subtotal column 1 =
Total ductwork =
Maximum Duct Length: For satisfactory air movement,
the total duct length of a 3 1/ 4” x 10” rectangular 6” or 7”
diameter round duct should not exceed 100 equivalent feet.
6” round to
3- 1/ 4” x 10”
rect.
transition
1 Ft. x ( ) =
Ft.
6” round to
3- 1/ 4” x 10”
rect.
transition
90
0
elbow
16 Ft. x ( ) =
Ft.
7” round to
3 1/ 4” x 10”
rect.
transition
8 Ft. x ( ) =
Ft.
7” round to
3- 1/ 4” x 10”
rect.
transition
90
0
elbow
23 Ft. x ( ) =
Ft.
Installation – Ducting Calculation Sheet