 That's normal. Your unit is sized that when it's this hot, it should run just about all the time. Okay. Changing the filter. Here's what I normally do, and you tell me if I'm right or if I'm wrong. I usually do it every other month, and I remember when I have to pay a certain bill, water bill, heating bill, whatever it is, that's when I'll change the filter. I go out and buy them a couple of times. Should I do it every month, or should it just be once a month, maybe twice a month?