I have heard horror stories from people who forgot to change the air filters in their a/c units, with them complaining that whenever they turned their a/c units on, they instantly begin to feel sick.
They won’t realize what it is at first, but eventually, they will begin to suspect that their heating, ventilation plus A/C unit has something to do with it. In this case, when they think to check their a/c unit, they remember that they haven’t changed their air filter in awhile. When they pull the air filter out of their a/c unit, it is covered in mildew and dirt… However, this was not our experience, because I change our air filter pretty often; but, this was the first time that I had forgotten. The a/c unit didn’t make myself and my wife sick or anything, but there were subtle signs that something wasn’t right in there. Our a/c unit was set to the coldest temperature, but it wasn’t blowing as strongly as it had in the past. When we listened to it closely, it would make slight whistling sounds that made myself and my wife think that our a/c unit was being obstructed from blowing as hard as possible. I checked the air filter in our a/c unit, and sure enough, it was a little dirty. I had a new one on hand, so I abruptly upgraded it and turned our a/c unit back on. So in this case, no harm, no foul. When you inspect and wash your a/c units as much as we do, you realize that you prevent major heating, ventilation plus A/C complications that lots of people experience. The next time your a/c unit stops properly working, check the air filter immediately.