In general, most air filter manufacturers and HVAC companies recommend changing the air filter every 90 days or 3 months. This can vary depending on the location of your home, if you have pets, and the age of your system and equipment. If you have pets at home, it is recommended to change the filter every 60 days or 2 months. For those with allergies or respiratory conditions, it is best to change the filter every 20 to 45 days.
Vacation homes or empty houses that are not used often should wait to change the filters every 9 to 12 months. The more you use your home, the more often you should replace the air filter. A general rule for pleated air filters is to replace them every 90 days. As the filter traps more dirt, dust, and allergens from the air, its efficiency decreases.
To determine if you should replace the filter more often, consider the type of filter you have. Fiberglass air filters are more affordable but less efficient at capturing dust and particles from the air. They usually need to be changed every 30 days or less. For basic air filters (1 to 3), brands generally recommend changing them every 30 to 90 days.
If someone in your family has mild to moderate allergies, you can put a better air filter on them or change them more often. In general, you should check your air filter once a month to see how dirty it is. If you or a family member has a history of allergies or asthma, plan to change your filter once a month following recommendations from medical associations such as the American Academy of Allergy, Asthma, and Immunology. If the air outside is of poor quality or you have pets inside, you'll need to change the air filter more often. Outdoor air quality can have a big impact on how often the air filter gets dirty and needs to be changed.
When you remove the air filter from the air conditioner, if you bring it closer to a light source, you can see if the filter is dirty or clogged. If you can't see the light through the filter, it's time to change it. After several smoke-filled days and poor outdoor air quality, inspect the air filter to see if it needs to be changed. Yes, changing the filter has several effects on the ability of the air conditioning system to cool the house and on overall air quality. Your home air filters need to be changed regularly to keep the system running smoothly and to maintain optimal air quality.
The Minimum Efficiency Value (MERV) rating of an air filter measures how effectively it prevents dust and other contaminants from passing through and entering into the air stream. The only type of filters that trap allergens and spores are HEPA, or high-energy particulate air filters. For starters, a dirty air filter can't capture airborne particles such as pollen or dust mite allergens which means they recirculate more particles for you to inhale. To keep your home clean and your air quality under control, replace your filter at least 2 to 3 months apart. There is no strict guideline but if you bring your filter closer to a light source and can still see light through it then it means that it is in good working order.
However, if it is impossible to replace the air filter for an extended period of time spending more than 90 days will not cause irreparable damage.
