 Don't feel guilty that you don't remember to change your furnace filters on a regular basis. I mean, come on, there are a lot of other things competing for your attention and energy. Look, here's a tip from the Air Filter Superstore. Set an alarm. That's right, set an alarm on your phone for when you should change your furnace filters. That way you will keep your indoor air quality in better shape and will maximize your heating and air conditioning efficiency, all while avoiding expensive repairs due to dirty and clogged filters.