Temperature control is a central part of the American way of life, from homes and vehicles to refrigerators and public spaces. Heating accounts for approximately 30% of residential home energy expenditure in the United States, and cooling accounts for an additional 12%.¹

However, despite its prevalence, the technology we use for heating and especially cooling is not particularly efficient—for example, standard vapor-compression refrigeration has an efficiency of just ~40%.² This technology—virtually unchanged in the past 70 years³—uses chemicals that release greenhouse gases into the atmosphere (the most efficient systems use Freon gases or cholorofluorocarbons and hydrochlorofluorocarbons).