How To Calculate Size of Air Conditioner

Air conditioners come in a wide range of different powers and efficiencies.

The basic calculation for the power of one of these units is the British Thermal Unit.

The BTU, which is a gauge of the cooling force of an air conditioner, gives you a metric to use in comparing units, the more BTUs, the bigger the unit, both in physical size and capacity.

That doesn't tell you much in terms of what an air conditioner can do, though.

To calculate the size room that a unit will cool, you can use a figure recommended by the Department of Energy.

How to Calculate Size of Air Conditioner

Find out what BTU output is

Find out what the BTU output is. The air conditioner should have it printed on the unit itself. If not, refer to the technical specs online or in the manual.

Divide BTUs by 20 to ascertain area that a unit will be adequate for

Divide the BTUs by 20 to ascertain the area that a unit will be adequate for. Energy Saver says you should figure, for each square foot, about 20 BTUs. Therefore, an air conditioner that is 7,500 BTUs is the right size for a space of 375 square feet.

Change your figure to square meters if you need to or if you are on metric system

Change your figure to square meters if you need to or if you are on the metric system.

One square meter is 10.76 square feet.

In this instance, you need about 215 BTUs per square meter.

A unit of 9,000 BTUs is the proper size for a room of about 42 square meters.