It's important to keep your home air filter in good condition to ensure the health and safety of your family. But when should you replace it? The answer depends on a few factors, such as the location of your home, if you have pets, and how old the system and equipment are. In general, most air filter manufacturers and HVAC companies suggest changing the air filter every 90 days or 3 months. If you have pets at home, you should consider changing the filter every 60 days or every 2 months, and for homes with multiple pets or people with allergies or respiratory conditions, we recommend that you change the filter every 20 to 45 days.
Vacation homes or vacant homes that don't get much use usually wait to change filters every 9 to 12 months. A sure sign that your air filter needs to be changed is if it's causing your HVAC system to overheat. If the back of the unit starts to get too hot or starts to blow out hot air, it's time to replace the air filter. Another indication that you need to switch out your filter is if someone in your household has allergies or asthma. The longer you wait to change your air filter, the more allergens will remain in your home, potentially making it more polluted than the outdoor air. The only way to know for sure if you need to change your air filter is to check it once a month.
If you or a family member has a history of allergies or asthma, plan to change the filter once a month, following recommendations from medical associations, including the American Academy of Allergy, Asthma and Immunology. Visible dust around the vents may indicate that the air filter is breaking down and releasing particles into the air conditioning system. This can be confirmed by taking out the filter and taking a look at it. If it's covered in dust or starts to disintegrate, it's time to replace this important component. If you routinely change the air filter in your air conditioning system, you'll keep it running smoothly and efficiently.
However, if your air filter is located on a high ceiling or near stairs, you may be more comfortable having a professional take care of it. It's important to note that there are high-efficiency filters that are designed to filter out small particles of bacteria, mold and mildew, but standard MERV 8-11 filters only block larger particles of dust, dirt and hair. The Department of Energy recommends replacing air filters regularly as the most important maintenance task your HVAC system must perform. Dirty or damaged air conditioning system filters can reduce airflow and cause problems with the performance of the air conditioning and heating system. In addition to reducing energy efficiency and causing indoor air quality problems, a clogged filter can restrict airflow. Air filters usually have a MERV (minimum efficiency value) that determines the type and size of the contaminants against which the filter acts.
If not replaced quickly, these filters can cause a system-wide breakdown and require emergency repair services for heating or air conditioning. Using an air filter with a MERV rating higher than that recommended by the boiler or air conditioner manufacturer can, in fact, affect its performance. Filters with higher MERV indexes trap small particles more effectively than filters with lower MERV indexes. You can also set up a reminder on your smartphone, writing down the date you last changed the air filter so you don't forget to check it again.