A cooling technology, if scaled up, could decrease temperatures by as much as 37 °C — potentially boosting the capabilities of refrigeration equipment.

Shanhui Fan at Stanford University in California and his team built a device that includes a thermal emitter that gives off heat in the mid-infrared range. Such wavelengths correspond to the 'transparency window' of Earth's atmosphere, allowing the heat radiation emitted by the apparatus to be released into space. Previous systems have reduced their temperatures by up to only 20 °C in low-altitude areas with moderate humidity levels. But the team broke this record with the addition of several features, including a vacuum chamber around the emitter. This ensured that heat was emitted only into space, and not into the surrounding air, increasing the amount of heat removed.

With further development, the technology could be used for applications including energy-efficient air conditioning.

Nature Commun. 7, 13729 (2016)