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Discussion Starter · #1 ·
Been comparing dust collectors and air filters. I've noticed that to get 1000 cfm in a dust collector whose filter captures 1 micron or better, you need between 1.5 and 2.0 hp.

Air filters with 1000 cfm also claiming 1 micron or bigger capture are rated around 1/5 of a hp.

Can someone explain why the big difference between the power requirements of each unit?? same flow rate, same filter rate ???

thanks
 

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That's an easy one a dust collector is collecting at the machine but the filter is cleaning the air. They do 2 different jobs.

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Sawdust Creator
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Dust collectors are also pulling much larger pieces...think saw dust and chips....where as air cleaners are scrubbing the air of fine dust ( think sanding dust)
 

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The DC is sucking through a straw (ductwork) to move that much air, and overcoming some significant resistance to do so. To do that, it's not spinning a lightweight squirrel cage fan, but an impeller that may be made of steel and has some weight to it. It's unlikely that a 1.5 to 2 HP DC will actually move 1000CFM, especially once it's hooked to a system. If you're looking at factory DC specs, they are normally done under a no load condition. Put any resistance (static pressure) on it and those numbers may well drop by 1/2 or more.
 

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you 're not comparing micron size filtration, as much as your comment compares cfm vs horsepower requirement. realize that cfm is a volume flow rate. and with any fluid power transmission, there is flow, and pressure (the element you are leaving out) although flow rates can be equal, the pressures at which they can accomplish the same flow are different.

obviously it will require more horsepower to provide the same cfm at higher pressures (positive or negative), than it will lower pressures. fan ratings are a certain amount of flow (cfm) x some amount of pressure (psi, in Hg, kPA)
 
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