Perhaps the most used furnace filter in the United States, the pleated filter is cheap and readily available. It comes in all necessary sizes and is very cost effective. The panel simply needs replacing once it is noticeably clogged with dust.
The reason for the pleating is to increase the surface area of filtration. If the filter were smoothed flat, the decreased surface area would cause the filter to clog more rapidly, requiring frequent changes. With the pleats, the dust is distributed over more material, taking longer for it to load up with dust.
The increased air flow offered by pleating the filter comes from the fact that as it takes longer to clog, the air can pass more smoothly through it, for a longer period of time, than if it were flat. Increased air flow translates to improved efficiency from the furnace, as it does not have to work so hard to pass air through it.
While electrostatic air filters are all the rage, pleated air filters pale in comparison. At a usual rate of only 20-30% efficiency, pleated filters are fast becoming unpopular with homeowners.
On the other hand, some manufacturers have gotten wise to this situation and have combined the best of both worlds. Nordic Pure is a manufacturer that produces electrostatic furnace filters which are also pleated, bringing them to an efficiency rating of more than 97%.
What’s more is that the electrostatic pleated filters are also treated with antimicrobial properties, helping it combat fungi, mold, dust mites, viruses, and other tiny living organisms. But if you cannot afford the electrostatic pleated filter, the pleated filter still beats out the disposable fiberglass panel filters. Basically useless, these lead to reduced equipment function and poor air quality. So, pleating really does make a difference.
