The Right Size of an Air Conditioner for a Bedroom With a Small Window

Measure the Room

• Measure the room, length times width, to determine what Btu requirements you need to adequately keep it cool. There are standardized cooling requirements that conform to room size. For example, a 10-by-15-foot, or a 150-square-foot room, only needs an air conditioner with 5000 Btu of cooling power, while an 18-by-25-foot room needs a 10,000 Btu air conditioner to keep the room cool. These are the minimum requirements for adequate room cooling.

Measure the Window Size

• Measure the window size to determine if a window air conditioner will fit. Most window units fit double-hung windows. They have adjustable side accordion pull-out panels that bridge the gap from side to side. However, mini compact air conditioners are made that fit into virtually any smaller-size window. They cost more than a standard size unit, but they cool just as effectively.

Environmental Factors

• Environmental factors include a room located on a sunny side or shaded side of the house. How many people use the room on a regular basis must be taken into account. For example, if the room receives full sun during the day, add another 500 to 1000 Btu of cooling power. A shaded room allows you to decrease the Btu requirements by 10 percent. Add an extra 600 Btu of cooling power for each person who occupies the room on a regular basis.

Portable Air Conditioners

• A portable air conditioner connects to a window through a hose. The units are mounted on wheels and easily travel from room to room where needed. Even the smallest window accommodates a portable air conditioner hose. If your window is too small, not high enough, or if you are not able to open it more than a few inches, a portable unit allows cooling power and vent through a 6- or 8-inch window opening.