I have a relative in a hospital bed in our drafty living room. The room is small enough (over 100 square feet, but close enough that this did the trick) that I decided to try this heater and it worked like a charm. It was a cold night and I turned down the thermostat below 70 and came back an hour later and the room temp was 73 and eventually got up to 76. I turned it off and moved it to my small bedroom and didn't leave it on as long, because I didn't want to be too hot. I got a second one for a relative who has health problems and is always cold and I am thinking of getting the next size up, because I think I could heat the whole house at one time and never use my heating oil or other space heaters again.