The air filters in my central heating and a/c need to be changed soon. I know this because I change the air filters once each month no matter what. I have found that when you change the air filters in your central heating and a/c components once a month you will have a better experience with both the indoor air quality plus the airflow in your central heating and a/c. Also on top of that I use the finest possible air filters out there which are the HEPA rated air filters for your central heating and a/c unit. I started buying HEPA rated air filters for my central heating and a/c a few years ago. This was after I heard about how good HEPA rated air filters for your central heating and a/c component were. Ever since I experienced HEPA rated air filters I am never going back to the generic air filters that I used to use for my central heating and a/c. HEPA rated air filters are where it is at and this is what I will keep. And changing the air filter every single month of the year to the central heating and a/c is the best thing I can do to keep my central heating and a/c components running nice and smooth throughout the year. I suggest you do the same as me if you don’t already!