Nanowerk March 8, 2022 In thermoelectric materials the hot side can be easily obtained by excess heat. Since thermoelectric voltage is proportional to the temperature difference between the hot and cold sides, efficient passive cooling to increase the temperature gradient is of critical importance. Researchers in Japan have designed a magnetic hybrid system where radiative cooling occurs at the top, as heat is lost from a material in the form of infrared radiation, while solar radiation is absorbed at the bottom. They demonstrated this concept by using the spin Seebeck effect. The device shows the highest thermoelectric voltage when both […]
Tag Archives: Radiative cooling
System provides cooling with no electricity
MIT News October 30, 2019 An international team of researchers (USA – MIT, Chile) has developed polyethylene aerogel (PEA)—a solar-reflecting (92.2% solar weighted reflectance at 6 mm thick), infrared-transparent (79.9% transmittance between 8 and 13 μm at 6 mm thick), and low-thermal-conductivity (kPEA = 28 mW/mK) material that can be integrated with existing emitters to address these challenges. Using an experimental setup that includes the custom-fabricated PEA, they demonstrated a daytime ambient temperature cooling power of 96 W/m2 and passive cooling up to 13°C below ambient temperature around solar noon. This work could greatly improve the performance of existing passive […]
Clever materials make it easier to pull clean water from the air
MIT Technology Review September 27, 2019 Providing the global population with clean drinking water is one of the great engineering challenges of the 21st century. As significant amount of water vapor is stored in the atmosphere, dew harvesting holds potential for freshwater harvesting. An international team of researchers (China, USA) has developed a theoretical framework to analyze due harvesting. They provided a numerical design of a selective emitter, consisting of six layers optimized for dew-harvesting purposes. According to the researchers at an ambient temperature of 20 °C (68 °F) with a relative humidity of 40%, the selective emitter could harvest […]