An air conditioner with 5,000 BTU is supposed to be able to decrease the temperature of 5,000 cubic feet of air by one degree in one hour. The air conditioning calculator shows that the air conditioner could be used in a room with between 200 to 300 square feet.The amount and quality of room insulation is also as important and a play vital role in the type of air conditioner you need. The kitchen also can increase the room temperature of the whole house and that should be taken in consideration as well.

In order to determine the correct and proper size of air conditioner, you should always ask the manufacturer to calculate the BTU required for your home or download an online calculator and do it yourself.You should also give some room for consideration. For example, if your air conditioning calculator advises to buy a 10,000 BTU unit, then you should buy a home air conditioner around 10,000 to 12,000.This also won't push it too hard and would also produce cool air and keep the proper room temperature. Since it will not work much harder and for longer periods of time, it can lower your electricity bills.

Source: Industrial Air Conditioner, Air Source Heat Pump