www.zephyronline.com
Installation - Ductwork Calculation Sheet
Duct pieces | Equivalent number | Total | |||
| length x used |
| = | ||
3 1/4” x 10” | 1 Ft. | x ( | ) | = | Ft. |
Rect., |
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straight |
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7” Round, | 1 Ft. | x ( | ) | = | Ft. |
straight |
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7” Round, | 1 Ft. | x ( | ) | = | Ft. |
straight |
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3 1/4” x 10” | 15 Ft. | x ( | ) | = | Ft. |
Rect. 900 |
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elbow |
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3 1/4” x 10” | 9 Ft. | x ( | ) | = | Ft. |
Rect. 450 |
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elbow |
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3 1/4” x 10” | 24 Ft. | x ( | ) | = | Ft. |
Rect. 900 |
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flat elbow |
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3 1/4” x 10” | 30 Ft. | x ( | ) | = | Ft. |
Rect. |
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wall cap |
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with damper |
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3 1/4” x 10” | 5 Ft. | x ( | ) | = | Ft. |
Rect. to |
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6” round |
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transition |
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3 1/4” x 10” | 15 Ft. | x ( | ) | = | Ft. |
Rect. to |
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6” round |
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transition |
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900 elbow |
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6” Round, | 15 Ft. | x ( | ) | = | Ft. |
900 elbow |
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6” Round, | 9 Ft. | x ( | ) | = | Ft. |
450 elbow |
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| Subtotal column 1 = | Ft. | |||
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.
Duct pieces | Equivalent number | Total | |||
| length x used |
| = | ||
6” Round | 30 Ft. | x ( | ) | = | Ft. |
wall cap |
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with damper |
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6” Round, | 30 Ft. | x ( | ) | = | Ft. |
roof cap |
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6” round to | 1 Ft. | x ( | ) | = | Ft. |
3 1/4” x 10” |
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rect. |
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transition |
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6” round to | 16 Ft. | x ( | ) | = | Ft. |
3 1/4” x 10” |
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rect. |
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transition |
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900 elbow |
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7” Round, | 15 Ft. | x ( | ) | = | Ft. |
900 elbow |
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7” Round, | 9 Ft. | x ( | ) | = | Ft. |
450 elbow |
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7” Round | 30 Ft. | x ( | ) | = | Ft. |
wall cap |
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with damper |
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7” Round, | 30 Ft. | x ( | ) | = | Ft. |
roof cap |
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7” round to | 8 Ft. | x ( | ) | = | Ft. |
3 1/4” x 10” |
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rect. |
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transition |
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7” round to | 15 Ft. | x ( | ) | = | Ft. |
3 1/4” x 10” |
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rect. |
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transition |
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900 elbow |
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| Subtotal column 2 = | Ft. | |||
| Subtotal column 1 = | Ft. | |||
| Total ductwork |
| = | Ft. | |
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