My dear sweet husband found this and did the research before showing it to me. I‚Äôm in the thick of menopause and the hot flashes are horrible. I just ordered a second one of these for next to me in the living room. The other is upstairs next to the bed. One tankful lasts me all night in low and it keeps me cool. So helpful and it keeps me from turning the a/c on 68 degrees 24/7 so I believe it will save money. So happy with this little gem.