When it comes to air filters, the 20x25x4 size is a popular choice for many homeowners. But how long do these filters last? Fortunately, most 20x25x4 air filters last between six and eight months. On average, you won't need more than two of these filters in a year. However, if you opt for pleated air filters, they can last up to 90 days depending on usage.
It's important to understand why you should change your air filter regularly. Not only does it help keep your indoor air clean by trapping mold, pollen and other contaminants, but it also ensures that your HVAC system works efficiently. The general consensus is that you should replace the filter every 3 months or 90 days. However, this can vary depending on the type of filter you use and the climate in your area.
Pleated air filters are more expensive at first, but they are also more efficient at trapping particles. If you live in a temperate climate and only use your air conditioner or oven for a few hours a day, a filter could last the entire season or even a whole year. On the other hand, if you use your HVAC system almost constantly, the filter will need to be changed every few weeks (especially if you use fiberglass filters). The Minimum Efficiency Report Value (MERV) of an air filter ranges from 1 to 16, with ratings of 6 to 12 being best for residential furnaces.
If you suffer from asthma or allergies at home, it's advisable to change the filter every 6 weeks to ensure the best indoor air quality. Stronger filters are reusable and usually have metal frames that can be cleaned according to the manufacturer's instructions. The only way to be sure how often your air filter should be changed is to do a visual inspection of the filter every month. Smaller rooms will not require a lot of pumped air, which entails a lower frequency of filter replacement. The only type of filters that trap allergens and spores are HEPA filters or high-energy particulate air filters.