If a new air conditioning unit is top priority to make your life bearable this summer, it is important to choose wisely.
The most important factor is to match the size of your room to the size of the appliance. An air conditioner that is too small will not be able to cool a room, while one that is too big costs more to operate and cools the area so quickly it won't have time to remove enough moisture, leaving a cold, clammy room.
To determine the proper size, measure the square footage of the area you want to cool. Increase the capacity for a kitchen or a room usually occupied by more than two or three people.
Cooling capacity is measured in BTU/hour (British Thermal Units per hour). The higher the number, the more powerful the unit.
A room of 150 sq ft may only need a 5,000 BTU/hour unit, whereas a room of 1,000 sq ft may need a 18,000 BTU/hour unit.
Room size is not the only factor that contributes to the capacity. There are other factors including the number and size of windows, direction the room faces, available shade, how well the room is insulated, how many people use the room and the number of appliances present.