A 1,000 BTU air conditioner has very little cooling power. The minimum rated room air conditioner by Energy Star is 5,000 BTU, which provides enough cooling for 100 to 150 square feet of space under normal operating circumstances. After that point, it recommends increasing the cooling capacity of the unit by 1,000 BTU for each additional 50 square feet.
When choosing a room air conditioner, it is essential to choose an appropriately sized unit. If the unit is too small, the compressor runs continuously, but the room rarely reaches the set temperature. Choosing an oversized unit allows the room to reach the set temperature quickly; however, the unit does not have time to reduce the humidity of the area leaving it feeling cold and damp. Units with adjustable louvers and multiple fan speeds help to ensure proper distribution of the air throughout the room.
The Energy Star recommendations are for operating the unit under normal circumstances. Environmental factors, including the sunlight exposure of the room, affect the amount of cooling required for the space. The number of people in the room also increases the cooling needs due to body heat. In a small kitchen, the heat produced by appliances almost doubles the cooling requirement.