Chinese and US scientists develop unique device to capture heat and cold – Xinhua

WASHINGTON, Nov. 8 (Xinhua) – American and Chinese scientists have developed a single device that can simultaneously capture the heat of the sun and the cold of space.

The study published Thursday in the magazine Joule described the solar and space energy recovery device that did not dispute land space but helped each other more effectively.

"It is widely recognized that the sun is a perfect heat source that nature offers to human beings on Earth," said the study's first author, Chen Zhen, a professor at Southeast University of China. "It is less commonly accepted that nature also offers human beings additional space as a perfect heat sink."

The objects give off heat in the form of infrared radiation and most of this radiation is sent back to the Earth, but a part of it escapes into space. It allows surfaces that emit enough radiation in the infrared range to drop below room temperature, thus providing an alternative to air conditioning that does not emit greenhouse gases.

If you have a single roof, installing a solar panel or radiative cooler has become an issue. Now Chen and his colleagues at Stanford University have developed a device that combines radiative cooling and solar absorption technology.

The device consists of a germanium solar absorber surmounting a radiative cooler with layers of silicon nitride, silicon and aluminum enclosed in vacuum to minimize unwanted heat loss, according to the study.

According to the study, the solar absorber and the atmosphere are transparent in the average infrared range of 8 to 13 microns, thus providing a channel for infrared radiation emitted by the radiative cooler.

They demonstrated that the combined device could simultaneously provide 24 ° C in solar heating and 29 ° C in radiative cooling, the solar absorber improving the performance of the radiative cooler by blocking the heat of the sun.

"On a roof, we imagine that a photovoltaic cell can provide electricity while the radiative cooler can cool the house during hot summer days," Chen said.

The team is working to reduce the costs associated with the infrared window to commercialize the technology in the coming years.