I spend 6 months in S Florida and also have the whisper quiet 15K. I always run the air on high only. I was getting a lot of dripping when I ran the air on low when it was humid outside. I went up on the roof several times and pulled the cover and saw the unit was freezing up. Haven't had any further problems as long as it stays on high with the dripping. But yeah, 1 air didn't cut for me either, as it never shut off (But, I have the 375BHFS so that makes sense).