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Hey Ed, What Is a Good Pressure Drop on a Filter?


In This Edition of “Hey Ed,” Ed Discusses What Is a Good Pressure Drop on a Filter

Hey Ed, what is a good pressure drop on a filter? Filters: lower is better and always will be. The idea that our industry has been asleep at the wheel for the last 20 years or more when it comes to pressure drops across filters is a reality. If you don't know specifically what the pressure drop is across the filter that you're installing, I am pleading with you to drill a hole above and below where that filter goes and measure the pressure drop. I think you'll be floored when you see how high it is. Filters, pleated filters, there's nothing wrong with pleated filters, but perpetually, we're installing ones that are too small. If we use more surface area, if we use two filters, and when I'm talking about two filters, not two filters, two filters, we double the surface area. If we double the surface area, that pressure drop based on the fan laws should drop by a factor of four. And that's the way I see it.

Ed Janowiak

Ed Janowiak is the Manager of HVAC Design Education at ACCA.


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