Air Conditioner Size, Strength, and Features

Armed with knowledge of type, technology, price and rating, it is time to head to the store. Final considerations should include overall air conditioner size, strength, and extra features.

Air Conditioner Size

Understanding what measurements to take depends on the type of conditioner required. For through-wall and split air conditioners, be sure to know the exact location of installation and take measurements of that area before making the purchase.

For window air conditioners, consider the inside dimensions of the window before purchasing. Considering the weight of the unit and the window's ability to support that weight is vital to selecting the correct window unit. (This is also important for installation-- the homeowner should be able to lift and remove the unit with minimal strain.) Optimal storage is another important size consideration.

Air Conditioner Strength

If the BTU rating is too low for the given space, the unit will run continuously without effectively cooling the room. This causes extra noise, energy consumption, and overall consumer irritation. An air conditioner with a BTU rating that is too high for the given space will also waste energy. While the space will cool rapidly, the conditioner will also cycle on and of continuously and rapidly, weakening the conditioner's ability to effectively dehumidify, as air circulation is limited. Use the rules described above to choose the perfect BTU rating for the given space.

Air Conditioner Size


It is a good idea to supplement any large purchase with a warranty that will cover repairs or replacements for defective units. Some stores offer an extended warranty for an additional price.

Temperature Range and Settings

Digital displays allow for greater control over cooling, and can prevent the nighttime chill that the generic low/high dial models can produce. Consider the temperature increments; the smaller the increments and larger the range, the easier it will be to precisely cool the given space.


Fan settings affects air circulation and noise. It is important to choose a unit with enough fan settings (in smaller increments) so that it may adapt to changing conditions, such as the outside temperature and time of day (for noise.)

Energy Savers

Many units offer sleep or energy saver settings. These are useful for saving energy (and money!) without turning the unit on and off constantly. The room remains at a temperature that is manageable, allowing it to cool to a comfortable level more quickly when it returns to normal power.


Air conditioners contain filters that remove dust and other particles from air that is being sent back into the room. Filters should be cleaned or replaced often, so units with a slide-out filter are ideal. Another option is a washable filter, which can save the buyer money.

Additional Functions

Some models include additional conditioner functions like purifiers, or a "dehumidify only" option. A more expensive model might even include heating options. Consider all other characteristics of the room or rooms to be cooled before deciding if these extra features are appropriate or necessary.

Bottom Line

Air conditioners are not one-size-fits-all. Ensure that you aren't the only one without during the next heat wave by doing your research and shopping ahead of time. An air conditioner of the correct size will provide years of quality and comfortable cooling to your home.

Also in this article:
Air Conditioner Guide
The Different Types of Air Conditioners