Cooling capacity ought to be your first thought before purchasing a window AC. Cooling force is measured in British Thermal Units, or BTUs, per hour–the fundamental measure of warm energy. For the best productivity and adequacy, stay with a unit that has a BTU level intended to fit your space. A window AC with too little BTU force will run persistently to attempt to cool a vast space and, all the while, will gobble up your energy spending plan. A window AC that is too extensive for your space won't cool and dehumidify your space uniformly, leaving your room air helpless to uncomfortable hot and frosty pockets. To locate your optimal cooling capacity, ascertain the measure of the space you need cooled in square feet. At that point utilize the diagram underneath to locate the appropriate measure of BTUs. Area To Be Cooled (Sq. Ft.) Capacity Needed (BTUs Per Hour) 100 to 150 sq. ft. 5,000 BTUs 150 to 250 sq. ft. 6,000 BTUs 250 to 300 sq. ft. 7,000 BTUs 300 to ...