New answers tagged ducts
Use an Anemometer to measure the air velocity, then multiply that by the cross sectional area of the duct. Circular Duct Air Velocity x (πr²) = Air Volume 4583.67 feet/minute x 3.14159265359 x ((4 inches / 12)/2)^2 = cubic feet/minute 4583.67 x 3.14159265359 x 0.02777777777777777778 = CFM 4583.67 x 0.08726646259972222222222222222222 = CFM ...
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I just did this this weekend. I imagine the answer really depends on the particulars of your duct work. Does it have a lot of bends? What's it made of? How long is it? Etc. In our case, we had smooth vent pipe, but they used 2' pieces to span about 14'. So we had all these tiny pieces with joints which, on top of that, they 'sealed' with duct tape. ...
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