When shopping for a window-mounted air conditioner, getting the proper size is essential. Window units are not designed to cool an entire home. They are instead used in individual rooms and offices that do not exceed a maximum of 400-500 square feet per installed unit.

The proper size to purchase begins with the room size. The room size is calculated by the length times width of the room in which the air conditioner will be installed. For example, a 10′ X 12′ bedroom would equal 120 square feet.

As a rule of thumb in Hawaii, most contractors use 50 BTU’s per square foot for calculating cooling load for un-insulated and single wall construction homes. This means that a 120 square-foot room would require approximately 6,000 BTU’s of cooling. Room size: 120 sq. ft. X 50 BTU = 6,000.

The air conditioner’s cooling load will vary due to insulation, amount of windows and the number of people in the room.

All room air conditioners produce condensation, which is moisture from the air. This condensation should be drained form your unit to the outside of your home.

All room air conditioners require an amount of electrical current called AMPS to run the compressor and fan. It is important that air conditioners be installed on a dedicated outlet that is of proper size, usually 20 AMPS. Never use extension cords on air conditioners. Clean your filters weekly for maximum cooling efficiently.