In general, most air filter manufacturers and HVAC companies recommend changing the air filter every 90 days or 3 months. This may vary depending on the location of your home, if you have pets, and the age of your system and equipment. If you have pets in the house, 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 best to change the filter every 20 to 45 days.
Vacation homes or vacant homes that don't have much use can usually wait to change filters every 9-12 months. The more you use your home, the more often you need to change the air filter. 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. Pleated air filters (such as those manufactured by FilterBuy) should be replaced every 90 days. As the filter traps more dirt, dust and allergens from the air, its efficiency decreases. In smaller homes, the HVAC system has to move less air, which can mean less frequent air filter replacements.
For most people, the difficult part of changing the air filter is determining what type of replacement you should get. When you begin to notice an increase in air particles or contaminants, the filter should be changed more frequently. A family of four will need to change their air filters more often than a single person's home. To keep air quality under control and your home clean, you'll want to replace the filter with a minimum interval of 2 to 3 months.
If you live in a big city, pollutants such as smoke, dust and other debris will seep inside and clog the air filter at a much faster rate. Studies have shown that the air in your home can be two to five times more polluted than outdoor air. The air filter helps your heating and cooling system do its job, keeps it running efficiently, and protecting it to last longer. If you live alone, without pets, and with good surrounding outdoor air quality, the manufacturer's filter change recommendations will probably work well for you.
During allergy season, air filters can work overtime to remove allergens, dust, and other debris circulating through the heating and cooling system. Since a clogged air filter restricts airflow, you'll often notice that the system works “as it normally does. The air cleaner and boiler filter replacement cycle is also affected by air outside and inside your home. Your air filter, once new, white and clean, will turn dusty and gray as you begin to spend months on return.