Some homeowners find the idea of washable air filters appealing. For one thing, they free you from the cycle of buying, changing and discarding air filters. Not only do you save money, but those disposable air filters you didn’t buy don’t end up in the landfill. Washable filters — also known as electrostatic or permanent filters — cost more, but can also pay for themselves over time and bear looking into.
Disposable air filters, be they inexpensive, fiberglass types or high quality, dense, pleated filters, work in basically the same way — by trapping particles in the fibers as the return air is drawn into the HVAC.
Washable air filters, which are made of several layers of vented metal, catch particles by static attraction as the air passes through the HVAC. Over time, the particles will collect on the filter and need washing away, or the filter will cease to become effective.
Electrostatic air filters do a pretty good job collecting dust particles but are not necessarily effective at stopping such particles as mold spores and pet dander. However, many homeowners find the advantages of not always having to change the air filter of sufficient appeal that they’re willing to make the switch to electrostatic.
If you decide to switch to these filters, bear in mind they need to be washed every 1-3 months. With some models, it’s necessary to take them apart and scrub the layers — an action that, with time, can wear out the filters so that they are no longer effective. Also, they must be dried thoroughly before they are put back together and re-installed into the HVAC unit.
As mentioned above, electrostatic filters also relieve the homeowner of the chore of always replacing and discarding air filters. And although they won’t last forever, they should last a long time: from three to five years on average.