Excellent little heater. When I first opened the box I thought that this little heater was going to have a difficult time heating my garage. Boy was I wrong. This little heater packs quite a punch. My garage is 24' X 24' X 9' high (576 square feet - 5184 cubic feet) in size. Granted, my garage is well insulated, however, I was extremely pleased that this little heater was able to heat my garage so quickly. I am extremely please with this product. I would highly recommend.