I can usually get my cold natured living room to 73 degrees in about 1.5 hours no matter what the outside temp, 75 after a little while longer. I'm finding 75 is all I can take - I'm already down to shorts and t-shirt. I keep a window cracked, and have a floor fan blowing cold air into the room, and the room will sit at 75. Sometimes it will climb to 78 and I have to go open the window and blow the fan even more. Whew! Not complaining - just curious. It does almost feel too warm at times - light sweat starts popping out. Better than cold thats for darn sure.