Central Air Conditioning Units
At one time, having a house with central air conditioning was the hallmark of luxury living. It soon became common in areas with long, hot summers because it adds not only comfort, but value to a home. Even as energy prices rise, central air remains a standard in American homes. According to government reports, between 1980 and 2001, the number of homes with central air conditioning overtook and surpassed those with window units and are now double.