I really like this machine I believe it works as should. Haven’t seen a increase in my electric bill as of now. I’ve had it for a little while. The only reason I give four stars instead of five is because I can’t tell that I have put essential oils in it. Usually you can smell them but with this I can not. Other than that it’s a great machine. I really like that I can adjust the fan speed too so when I’m not needing it as much I can set it to one. Even on three the noise isn’t bad. Not enough to complain about.