I bought it because it said it heats 700 - 1000 Sq feet and I thought I could use it to heat my whole house but after reading the paper that comes with it, it says it only heats 700 - 1000 Sq ft if you have another heating source. It says if you're using it as a main source of heat it only heats 150 sq ft. If it's above 50 degrees it keeps it warm in here but once it gets down in the 40s it's still a little chilly but not too bad. But I'm also running 2 other space heaters at that time also and have hardly any instalation.