A room air conditioner is a small, self-contained unit designed to cool just one room of a building. While most models of room air conditioners are placed in windows, there are some models that are installed to go through an exterior wall opening. These small air conditioning units must be placed in a window or in a wall opening, in order to allow for the air exchange that is needed for the unit to function properly.

Room air conditioners are often a good choice for renters, since they can be removed fairly easily and can be reinstalled in a new location. The drawback is that these small air conditioning units tend to be quite a bit less energy efficient than a central air conditioning system would be.

To encourage residential customers to make choices that will save on electricity usage during the summer months, there are many utility districts that have launched a "Be Cool" campaign. The purpose of this effort is to promote the benefits of buying room air conditioner models that are as energy efficient as possible.

In some areas, the local power companies are even encouraging the residents to trade in their old air conditioners and replace these less efficient units with Energy Star qualified room air conditioners. The "BE COOL" challenge winner will be the participating community that gets the highest percentage of area residents to take part in the campaign.

Recently, another advantage to using energy efficient air conditioning systems is a federal tax credit. Individuals who choose to install any type of air conditioning units, which are Energy Star rated, will be eligible for a federal tax credit of as much as $300.

The air conditioning units that qualify for this tax credit are obviously costlier to purchase than the ordinary air conditioners that consume more energy to operate. However, calculating the tax incentive, along with the savings in the cost to run the unit, clearly shows that it is well worth it to install new units that qualify.

Even with a savings of just $10 a month on the electricity bill adds up to $120 for a year. Add that minimum savings to that the tax credit of $300, and the net saving is $420 for the first year.

In most instances, this amount will more than offset the initial, higher cost of energy efficient, air conditioning units. On top of that, the energy efficient air conditioning unit will also continue to save money each year and make it more affordable to run.

When choosing a room air conditioning unit, experts advise that it is best to purchase the best model that is affordable, but not necessarily the biggest unit. The unit should fit into the amount of space available, while taking into consideration the room size.

Buying a room air conditioner model that is bigger than what is needed actually means that it will be using more energy and will not be efficient at all. This wasted energy is because of the cycling of the motor that works to keep the room at the right temperature. On top of an ineffective use of energy, this also means there is more wear on the moving parts as well.