You should replace your air conditioner filter approximately every 90 days, if you don't have allergies. However, AC professionals generally recommend changing it every 45 days for maximum efficiency. Be sure to replace it with 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 to it.
In general, most air filter manufacturers and HVAC companies suggest changing your air filter every 90 days or 3 months. This may vary depending on the location of your home (e.g. dry and dusty climates), if you have pets, and the age of your system and equipment. If you have pets in the house, you should consider changing the filter every 60 days or 2 months, and for households with multiple pets or people with allergies or respiratory conditions, we recommend changing the filter every 20-45 days.
Vacation homes or vacant homes that don't have much use can expect to change filters every 9-12 months. The only way to ensure how often you need to change your air filter is to perform a visual inspection of the filter every month. After a few months, you'll get an idea of how quickly it gets dirty. You will need to re-evaluate if you have a new pet or if the outdoor air quality has been poor. A general rule of thumb for pleated air filters (such as those manufactured by FilterBuy) is to replace the filter every 90 days. As the filter traps more dirt, dust and allergens from the air, its efficiency decreases.
You should consider replacing the filter more often if certain factors are present in your home. For a little-used vacation home, you could get away with changing filters once a year. However, for a typical suburban home, you'll probably want to change filters at least every 90 days. But that time frame changes depending on additional circumstances such as location, pets, age of system and equipment, outdoor air quality, etc. Cats and dogs typically lose the most when winter turns to spring and summer to fall, which are key times to replace the filter. Children are more sensitive than adults to indoor air pollutants such as mold, dust mite debris, dander and pollen, so make your home an oasis by using quality air filters and replacing them before they become too clogged and dirty. If you purchase an older system, plan to replace the filter more often to maintain filter quality.
Selecting the right size for your system is critical, as using the wrong size can cause many of the same problems as not replacing the filter at all. Families with children need to be more diligent in replacing their HVAC filter to preserve the cleanliness of their home and prevent diseases. For every dog that loses hair, expect to replace the filter a month earlier than you would with a pet-free home. As a general rule, it's a good idea to replace the air filter in your HVAC system every month. During times when you use your system frequently, you can even benefit from replacing filters every few weeks instead of every month. If the dirty air filter is completely covered with dust and dirt, it is a good idea to change the filter even if it has not reached the end of its recommended life. Regularly replacing your HVAC filter is one of the simplest home maintenance tasks you can perform but many people don't keep up with this, significantly shortening the life of your HVAC system and increasing the cost of your monthly utility bills.
