From a reusable filter to a highly rated electrostatically charged option, homeowners have five options to choose from in the 20x20x1" size category.

The MERV 13 pleated filter comes in a package of six and captures airborne allergens smaller than 1 micron. It's effective at reducing allergens like bacteria, mold spores, fine dust and pet dander. This filter is more than 30 times more efficient at capturing micro particles than ordinary fiberglass furnace filters.

Another option is the MERV 11 pleated filter, which is continuously bonded to a 30 gauge galvanized metal support grid. This filter is pleated to maximize its surface area and dust holding capabilities.

The MERV 8 pleated designer is excellent for high-velocity equipment and provides strong performance at an affordable price. It's listed and rated by Underwriters Laboratories as U.L. Class 2.

The MERV 4 fiberglass panel filter works well for light- and medium-duty air filtration applications. It's often used as a pre-filter for extending the lifespan of high efficiency filters.

An alternative to disposable filters is the permanent washable filter that's rated at MERV 5. It's easy to install and is interchangeable with one-inch disposable filters. This filter is also easy to clean; just backwash it every month with cold water.