I am in my room. I turn off all the heat but the furnace would kick it at 55 degrees which is 13 c . My room is heated my 10 tea light candle and it not bad. They do produce a lot of heat. And at 4 cent a candle I heating my room at 10 cent an hour. That messes up. I'm not cheap I just want to used all these candle up but it is working. The heat I mean.