Apollo sells and installs only SEER 13 air conditioning systems as required by the U.S. Department of Energy starting in January 2006. Every air conditioning unit is assigned an efficiency rating known as its “Seasonal Energy Efficiency Ratio” (SEER). The SEER of a unit represents its efficient use of energy. According to the Department of Energy, the new SEER 13 standard will have an energy net savings of approximately $1 billion to the consumer by 2020.