Sorry, which brand are you using? Remember, mine is 16000 BTU, Gree CITH series. 18000 BTU will consume more power. Of all brands, I have found out Acson > Gree >> all others. Haier is simple crap. I worked lots of graphs on that. It was simply the most pathetic. So brand does matter. I found that Haier's programming was awful. Just a waste of a job.