Can I Use a HEPA Furnace Filter?
A HEPA filter uses a dense filtration material and must remove at least 99.7% of airborne particles that are 0.3 microns or larger. This level of filtration is much better than a standard pleated or fiberglass filter.
Unfortunately, HEPA filters restrict too much air to be used as a traditional furnace filter. A HEPA filter is extremely efficient, but a significant amount of air pressure is needed to force air through a HEPA filter. A typical HVAC system will not be equipped to provide enough air pressure to use a HEPA filter (which means that no air would blow out of your registers).
In order to use a HEPA filter for whole house filtration, you need to install a separate HEPA filtration system. A system like this will pull some of the air out of the regular air flow through your furnace, and then boost the air and pass it through a HEPA filter. The extremely filtered air is then returned back into the normal air flow.
Save Your Furnace Tip #3:
Did you know that the nominal size of your air filter is probably not the same as the actual size? Just like measurements on lumber, the actual size of an air filter is usually slightly smaller than the nominal size.