As recently as December 2013, President Obama said that the U.S. federal government must double its reliance on renewable energy by 2020, meaning that 20 percent of its energy supplies will need to come from renewable sources. The reliance on green energy has several benefits, including the ability to decrease the “environmental footprint” on the plant, according to the U.S. EPA as well as to alleviate energy security issues while spurring economic growth within the U.S. Of course, this growing trend has resulted in many changes in HVAC technologies. Companies in the U.S. and worldwide are involved in research to create more energy-efficient traditional systems as well as new types of systems that run off alternative energies, such as geothermal or solar. Our list of 7 Green Technologies That Are Changing HVAC takes a look at changes in simple components as while as entire systems in HVAC. Still, even more improved technologies can be expected in the future as companies work toward changing this country’s reliance on fossil fuels, which in the U.S. stands at 82 percent. Only about 9 percent of the country’s energy supplies currently make use of renewable sources, which leaves plenty of room for change in HVAC systems.