Five filters are available in this size. One of them is fiberglass, three are pleated and the final one is washable. All of these quality discount filters will provide good performance in any HVAC system. They will fit in any HVAC system that takes a filter of this size; simply slide out the old filter and slide in the new one.

The fiberglass filters are designed for light applications. They have a MERV 4 rating, which means they will remove pollen, dust and lint. Each filter will only last for a month, but they come 12 to a box.

Pleated filters are up to 30 times more efficient than the fiberglass versions. They also have a lower pressure drop, which keeps the furnace operating more efficiently. No chemicals are added to the filters and bacteria, mold and mildew cannot grow on them. Each filter will last up to three months. Three different ratings are available: MERV 8, MERV 11 and MERV 13. Higher rated discount filters have better performance and remove more pollutants.

The final option is a permanent, washable filter that will last a lifetime. These quality filters can be interchanged with the disposable filters and are easy to wash. These filters use stage loading instead of face loading and do not use the foam that is commonly found in other permanent filters, so they will last longer and have better performance.