600 square feet.
1500 sq ft.
around 400 SF, not ft
One ton of air conditioning can cool approximately 600 square feet of area, if the climate is not too hot and humid. Using that formula, a four-ton air conditioner can cool about 1600 square feet of area.
900
An 800 square foot area need a 15,000 BTU air conditioner to properly cool. Properly sizes the AC unit ensures that the unit will not be overworked.
It depends on the climate, insulation, and layout of the room. In general, a 1 ton air conditioner is suitable for a room between 400-800 square feet, so it may struggle to adequately cool a room of 1800 square feet. It is recommended to use a larger capacity air conditioner for a room of that size.
About 365 square feet.
4000btu
An 800 square foot area need a 15,000 BTU air conditioner to properly cool. Properly sizes the AC unit ensures that the unit will not be overworked.
According to the Energy Star chart, 12,000 BTUs will cool a room of 450 up to 550 square feet. I'd stay on the low end of that.
Roughly 320-350 square feet.