Figure 1 - Window or wall air conditioner
Selection of window air conditioners
While most window air conditioners have flanges and expanding flexible screens to seal the unit to the sides of window frames very few, if any actually have a tight seal. It is generally necessary to plug gaps and holes to prevent insects and inclement weather from coming into your home or office.
Window air conditioners come in a variety of sizes. Although most window air conditioners do not require special electrical outlets, it is important to ensure that the electrical circuit that you are planning on plugging the unit into is capable of handling the current (amp) requirement.
If you have to use an extension cord to operate the unit make sure that the wire gauge is correct. You can purchase extension cords that are specifically designed for appliances such as air conditioners. Using an underrated extension cord can damage the air conditioner and worse, cause a fire.
Most air conditioners have their capacity rated in British Thermal Units (BTU). Generally speaking, a BTU is the amount of heat required to raise the temperature of one pound (0.45 kg) of water 1 degree Fahrenheit (0.56 degrees Celsius). Specifically, 1 BTU equals 1,055 joules. In heating and cooling terms, 1 ton
equals 12,000 BTU.
Air Conditioning Sizing Chart:
The Energy Efficiency Rating (EER) of an air conditioner is its BTU rating over its wattage. For example, if a 10,000-BTU air conditioner consumes 1,200 watts, its EER is 8.3 (10,000 BTU/1,200 watts).
Figure 2 - Wall mount air conditioner sleeve
Wall air conditioners:
Some manufacturers make units specifically designed to mount through a wall or sleeve, that they manufacture to suit their wall mount air conditioners, as shown in Figure 3. The internal functions are the same as window units, but they do not have any method of conveniently closing in the sides, or top. Hence, they must be mounted in a cut-out that is the correct size for the box that the air conditioner is housed in.
As well, most window air conditioners are designed to exhaust air through the sides and the top, whereas a wall mount air conditioner only exhausts air through the back.
Wall air conditioners do not come in the smaller BTU ratings of window air conditioners.