It’s not exactly a looker, but a five-foot tall, A-shaped engineering rig at the University of Maryland’s College Park campus could potentially evolve into a partial solution for a warming planet. At the heart of this refrigeration prototype is a material that gets cold just by being squeezed and released. It’s one of many so-called caloric materials that could provide for the world’s rapidly expanding cooling needs without exacerbating climate change. These materials cool in response to pressure, electric fields, or magnetic fields. Completely absent from this solid-state cooling concept are the volatile liquid refrigerants that are the lifeblood for just about all current cooling technologies and that are important contributors to global warming.
As the world’s billions of air conditioners, refrigerators, chillers, and dehumidifiers age and become throwaways, their refrigerants mostly leak into the atmosphere, where they trap solar radiation far more powerfully than carbon dioxide. And every day, the increasingly sweaty citizens of the planet install about 260,000 new air-conditioning (AC) units. At that rate, the number of ACs will likely balloon from the current 1.2 billion or so to 4.5 billion by 2050 [1]. The vapor-compression systems inside cooling appliances already consume about 20% of global electricity, the generation of which is a top source of humanity’s carbon dioxide emissions. Without a planet-wide redo of cooling technology, the explosive growth expected in cooling demand and supply is destined to make global warming worse. And that, in turn, will increase demand for more cooling.
