250 sq. ft to 450 sq 12,000 BTU is equal to 550 sq. ft to 800 sq. 15,000 watt is 750 sq. ft to1100 sq. 18,000 BTU is about 850 sq. ft to sq. This is the size of the building.
Let's Get It Fixed!
HomeX virtual experts will assess your issue (for free!) and can resolve simple problems.