Room Air Conditioners, Some Pros and Cons

A room air conditioner is just an ac unit designed to cool a single room. There are basically 3 types commonly used in residential applications, including portable, window, and through-wall air conditioners. What follows is a discussion of issues one might consider when deciding which is best for a given application.

Portable air conditioners have the advantage of portability and are easy to install without altering the building, but are somewhat limited in terms of power (most brands have a 14,000btu max for home style units). They have a 'footprint', meaning they take up a little floor space, and require a sliding window in the room or some additional work to vent through the ceiling or wall. They are excellent for offices or smaller rooms up to about 400 square feet, especially when supplementing central air.

Window and through-wall units are generally more efficient because they don't have to contend with moving air through ducts (which creates resistance) like portable ac's do. Many manufacturers offer models with more power, up to about 25,000btu, so they can be used for larger rooms than portable models. These factors often make them a better option when functioning as the sole source of cool air, i.e., when they are not supplementing a central air system. But be sure about the proper power supply, because many larger models require a 220 volt supply. They do not have a footprint but are more visible from outside, so some apartment complexes and homeowners associations restrict their use. They are less mobile than portable air conditioners but can be moved if necessary. Window units obviously require a window large enough to accept the unit. Through-wall units require a hole in the wall, and therefore a more permanent installation. This makes them a less attractive option for a building the buyer doesn't own. But once installed, through-wall units typically look a bit more 'finished' than window units. Portable air conditioners and window units are therefore easier to move than through-wall units, should you leave the original office or home. Any of the styles can be found with a heat function, a nice option for year-round comfort.