My living room is approximately 350 sq ft with very high ceilings and this humidifier was able to change the room humidity from 29 to 34 according to my nest thermostat in about three hours. I also used the diffuser and it also works perfectly. I read other reviewers say that the scent given off only lasts for a little while. Well I still have the scent spilling out of the humidifier three hours later. I really think it has to do with the quality of the oils not this humidifier. It's well worth the money.