Air Conditioners

When choosing an air conditioner to buy, it's best to first evaluate your options on the basis of needed capacity and best fit. Before you shop, find out the square footage of the room the needs to be cooled.  If you are getting a portable or window unit, measure the window opening.

While there ere are many notable distinctions between brands, unless you are loyal to one in particular, most offer the same basic products, so you should go into your search staying open to the many possibilities. Price is mainly a function of the style and BTU power, although efficiency is rapidly becoming an important distinguishing feature as well.

Air Conditioner Types

There are essentially 4 types of residential or light commercial air conditioners: portable standalone units, thru-wall and in-window room units, ductless mini and multi split systems and packaged central air conditioner.

Each of these types can be further subdivided along the lines of BTU output and operational features, but, with the exception of some central air systems, all are powered by either 120- or 240-volt electricity.

Portable Units

Portable air conditioners are standalone units that usually feature durable casters for easy mobility. Their power output ranges from 5,000 to about 12,000 BTUs per hour and they plug right into a standard wall outlet.

Different models from the various makers come with a whole range of features, from remote control and digital display to 4-in-1, cooling/fan-only/dehumidification/heating capability.

Portable air conditioners are space saving and energy efficient. Programmable timers and energy saving modes combine compressor use with fan-only settings to maintain cool temperatures while conserving power. This type of air conditioner is ideal for small to medium-size spaces or to supplement a central system.

These are unvented air conditioners, so look for the models that use evaporative technology and have no water bucket to empty.

Wall/Window Units

Thru-wall and in-window air conditioners install, as their names suggest, either into an opening in a wall or in a traditional window. In both cases they require a sleeve or chassis for installation. Window units tend to be a bit more portable, especially when equipped with slide-out chassis. This enables them to be installed and removed easily.

Both types vent to the outdoors and provide a range of cooling and heating options, from 5,000 BTU to 36,000 BTU output. Like their portable counterparts, numerous operational features are available with wall and window units including remote control, multiple cooling and fan settings, dehumidification mode and built-in heat pump for use during the cold season.

Certain models are Energy Star rated, and many units come with a high energy efficiency ratio (EER). Room wall and window units are capable of cooling spaces as small as 150 square feet all the way up to large rooms or whole floors, depending on the BTU output. Many models require 120-volt power, but some heftier units that draw more amps need 240-volt hardwired power.

Other features commonly found on these units are auto restart, removable and washable filter and anti-corrosion outer grilles and fins.

Mini and Multi Split Systems

Perhaps the most energy efficient of all air conditioners, mini and multi split systems combine elements of central air with room units to provide wide-reaching cooling while giving you complete thermostatic control of individual cooling zones. These systems are ductless, meaning they do not need the circulate cool air through a home's existing network of the heating ducts like central systems do.

Split systems consist of 3 main components: an outdoor condenser/compressor unit that is fixed to a stable surface, an indoor wall-mounted unit that contains the air handler and a one-touch remote control. The outdoor unit ensures that the air conditioner functions almost silently indoors. Because air is not channeled to the whole house from a central location, you can control where it comes out.

Mini systems feature a single wall-mounted unit generating 9,000 BTUs or higher, while a multi system features up to 4 units that generate a total of up to 42,000 BTUs divided between them. With multiple units each independently controlled, you never have to waste energy in zones not currently in use. For this reason, split systems give you the most flexibility in terms of cooling, while still providing a considerable amount of output. They are also much easier to install than a central air system.

Central Air Systems

Most commonly packaged one outdoor container, central air systems pipe refrigerant-cooled air to your home's existing network of heating ducts and distribute it throughout. New central air conditioners are designed to be energy efficient and must have a minimum SEER rating of 13, although more efficient units are widely available.

Central units are ideal for large homes in warm climates that require frequent and consistent cooling. They can be expensive to purchase and require a somewhat major installation, but they will last for a generation if well maintained.

Air Conditioner Brands

air conditioner manufacturers range from household names to less well-known brands that nonetheless make high-quality products. Some of the bigger brand names that produce one or more types of air conditioners include General Electric, Mitsubishi, Sanyo, Frigidaire, Kenmore, Whirlpool, Carrier, Amana and Maytag. Among the less well-known air conditioner brands you find Fedders, Goodman, Haier, Soleus, Sunpentown, Friedrich, LG, Pace Air, Napoleon, Amcor, Danby, OceanAire and Whynter.