Buildings are the single largest energy-consuming sector in the U.S. They use 39% of the nation’s total energy and 74% of its electricity. On average, air conditioners and electric fans account for approximately 20% of a building’s total energy consumption. But with climate change, that is set to increase. Cooling is the fastest-growing use of energy in buildings, with some estimates suggesting that energy demand for space cooling will more than triple worldwide by 2050.