How to Size Air Conditioners for Buildings

Sizing air conditioners for buildings will require some research. You want a unit that will properly cool the entire building without wasting money or energy. You’ll need to measure the building to determine the necessary BTUs required. Some buildings may require more than a single unit depending on the layout.

When getting an air conditioner for a building it is important to know how to properly size it. One that is too small will not properly keep the building cool while one that is too big can be a problem for your electric bill.

• Go into the building with a measuring tape and start to measure the height and length of the walls and ceilings. Only do this in the rooms that you plan on being air conditioned. If there is a room that has a doorway or opening, then it needs to be treated as a single room.


• Know whether or not the walls in the building are insulated. A room that is not insulated will need a BTU range that is higher because the cool air can get out. Figure in the windows that are in each of the rooms that will be air conditioned. Multiply the height and width of the windows and increase your BTU range 200 BTU for each 10 square feet of space.


• Consider how many people will be in the air conditioned rooms. Remember that each person will create their own amount of about 380 BTU.


• Think about each kitchen that will be in this building. A kitchen can add about 1,200 BTU of heat. Consider the heat from the kitchen in the total BTU you choose.


• Count the amount of appliances that will be giving off heat. A lot of lights can make a room get hot faster. A single kilowatt hour of energy is the same as about 3,413 BTU per hour.