Washable air filters are a great option for people looking to save money, but they are not very effective at capturing microscopic particles that can lower indoor air quality. With a maximum MERV rating of 4, washable filters cannot remove pet dander, smoke, bacteria, viruses, or other small particles from the air. If your family has allergies or asthma, a disposable filter is the better choice. Electrostatic filters, also known as washable oven filters, are another type of filter that can be used in HVAC systems.
As air enters the vents and return ducts, it passes through the filter to remove dust and dirt before the HVAC system conditions the air. Washable filters can last up to 10 years if they are well-maintained and gently cared for when washed. Disposable filters with MERV ratings between 9 and 12 have moderately high filtration and can remove the smallest contaminants from the air in your home. They should be replaced every month to ensure optimal performance.
If you forget to replace a fiberglass filter, a disposable pleated filter may be a better option. Particles that remain lodged in the filter can slow down the HVAC system's airflow over time, leading to costly problems. Mechanical filters are available in both washable and disposable versions and should be changed according to the manufacturer's instructions.