It rained a lot last night. There was a big thunderstorm with lots of lightning too. I kept feeling very hot and uncomfortable all night but I was too lazy to get up and check the air conditioner. When I finally got up this morning I noticed that it is 79 degrees inside the house even though the air conditioner was running nonstop. It seemed a lot quieter than normal too. When I went outside to check on my HVAC unit I didn’t see anything abnormal until I removed the filter. The filter was frozen and had chunks of ice on it. I use one of those tightly knit HEPA filters that is supposed to filter out everything. Unfortunately, this seems to have resulted in moisture from the air accumulating in the filter and freezing. With the filter removed, my air conditioner worked perfectly again. I left it running and went to the store and bought a cheap filter that was practically see through. When I got home, my house was at 75 degrees and still dropping. I installed the cheap filter and the air conditioner is still working well. I don’t imagine this freezing of a strong filter is normal though and I am starting to wonder if there might be something bigger wrong with my air conditioner. I should probably call an HVAC company to come and run some diagnostics just to make sure it is ok. I would hate to have to pay for an expensive repair but it is better to have it done now than to wait and go without air conditioning for days or weeks and have to pay for even more parts.