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Hey Ed, How Often Are Filters Sized Properly?

In This Edition of “Hey Ed,” Ed Discusses How Often Are Filers Sized Properly

Hey Ed, how often are filters sized properly? Very rarely. Then, I can take that a step further. If you've got a one-ton or a ton and a half, maybe a two-ton piece of equipment, and the installer is using the filter rack that came as an accessory or maybe came with the furnace, it might have enough surface area. But when we start getting into larger airflow requirements, two and a half, three, four tons of air, if you're using the filter rack or one side of the furnace to install a filter rack, unless we're getting in the four-inch pleated filters, the likelihood of having an acceptable velocity in that application is slim to none. So, accessory filters that are four inches or bigger are the way to go. Multiple filters, and when I'm talking multiple filters, I'm not talking about filters in series, I'm talking about filters in parallel, that's the way to go. The final thought is if you're not using some sort of math to determine if you have enough surface area to keep a reasonable face velocity with your filter selection, then you're doing it wrong - you can do it better. And that's the way I see it.

In This Edition of “Hey Ed,” Ed Discusses How Often Are Filters Sized Properly

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

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