If you don't suffer from allergies, it is recommended to replace your air filter every 90 days. However, air conditioning professionals usually suggest changing them every 45 days for maximum efficiency. Make sure to purchase the correct size and type of air filter. If your air conditioner is working properly, you can remove the filter and buy one that is identical.
Generally, most air filter manufacturers and HVAC companies suggest changing the air filter every 90 days or 3 months. This may vary depending on the location of your home (e.g. dusty and dry climates), 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 households with multiple pets or people with allergies or respiratory conditions, it is suggested to change the filter every 20 to 45 days. Vacation homes or empty houses that are not used often can wait to change filters every 9 to 12 months. The general consensus is that the more you use your home, the more often you will need to change your air filter. The only way to be sure how often the air filter needs to be changed is to perform a visual inspection of the filter each month. After a few months, you will get an idea of how quickly it gets dirty.
You should re-evaluate if you are going to have a new pet or if the outside air quality has been poor. The ideal situation is to change your air filter every three months; however, there are certain factors to consider when determining when to replace an old filter. How often you should change your air filters depends on how often you use your home. For an underused vacation home, you can get away with changing the filters once a year. However, in the case of a typical suburban home, it is suggested to change the filters at least every 90 days. This time frame may vary depending on additional circumstances such as location, pets, age of system and equipment, etc.
If you live in a big city, pollutants such as smoke, dust and other debris will seep inside and clog your air filter at a much faster rate. A single person without pets will have to change their air filters much less frequently than a family with children and several pets. These air filters act as barriers to prevent contaminants from entering the HVAC system or circulating through the air. While these factors affect the frequency of air filter replacement, it is important to visually inspect the filter each month for excess particulate buildup. If the dirty air filter is completely covered with dust and dirt, it is best to replace it even if it hasn't reached the end of its recommended lifespan.
