New MIT Passive Cooling System Works Without Electricity.
As climate change drives up summertime temperatures, the demand for air conditioning is placing an unsustainable strain on power grids while generating greenhouse gas emissions. To address this growing energy challenge, a team at MIT has developed an innovative passive cooling device for buildings that requires no electricity whatsoever.
The novel device resembles a solar panel in its basic layered structure. The front layer serves as a broadband solar reflector to minimize heat absorption from sunlight. Behind this reflector is an evaporative cooling component that uses evaporated water to cool hot incoming air before it enters a building. Any remaining heat not absorbed by the evaporator gets emitted skyward from the back insulation layer through a process called radiative cooling.
Unlike conventional air conditioners, which use electricity-hungry compressors and refrigerants, this system provides a completely passive, renewable means of cooling by combining nature-inspired evaporative and radiative cooling principles. It simply leverages water, sunlight, and outer space to provide cooling flows, significantly reducing daytime air conditioning demands during hot, dry weather.
Early real-world testing on a prototype device displayed exceptional results – providing nearly 11°F of cooling during testing in Arizona when it was over 100°F outside. While refinements are still needed for varying humidity conditions, the researchers believe this technology could significantly curb air conditioning energy usage in arid climates, providing more than 40% energy savings in some building applications.
“We now have the first holistic design of a climate-responsive building component that consumes no traditional energy and can achieve significant temperature reductions through passive means,” stated MIT professor Evelyn Wang. As rising temperatures increase cooling demands globally, passive cooling innovations like this will grow ever more critical in the years ahead.
