Power Lost on Restriction in Ductwork

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gm10
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Hello,

I need a formula to calculate how much power is wasted on different types of air filters. A typical application is a residential central air ductwork. A typical pressure drop is 0.1-0.2 inch wg. Typical volume passing through filters is 700-2000 cfm. A typical filter size is 2-3 sq. ft.

Your help is much appreciated in advance.

gm

This is not a homework. :smile:
 
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Welcome to PF. The equation is:

CFM*dP/6356/eff=hp

That's flow in CFM, dP in inches w.g. and efficiency of the fan. A typical good HVAC fan is about 65% efficient, so for example, 2000 CFM at 0.2" is 2000*.2/6356/.65=0.097hp
 
russ,

Awesome. Thanks a lot.