How often do you check your A/C filters?
I think most replacement filters suggest every 60 days, but I think a more appropriate answer is when they are dirty. The rest of the answer is how many contaminates are involved with your home? Do you have pets, do you live in an area where they have smog days and how many people live in your home? What about allergies, do you or someone living in your home have allergies? If you answered yes, then you should consider special filters that collect more contaminates. Dust mites, German Cockroaches and other pests can increase asthma conditions and should be prevented.