A team of University of Colorado Boulder engineers has developed a scalable manufactured metamaterial — an engineered material with extraordinary properties not found in nature — to act as a kind of air conditioning system for structures. It has the ability to cool objects even under direct sunlight with zero energy and water consumption.
When applied to a surface, the metamaterial film cools the object underneath by efficiently reflecting incoming solar energy back into space while simultaneously allowing the surface to shed its own heat in the form of infrared thermal radiation.
The new material, which is described today in the journal Science, could provide an eco-friendly means of supplementary cooling for thermoelectric power plants, which currently require large amounts of water and electricity to maintain the operating temperatures of their machinery.
The researchers’ glass-polymer hybrid material measures just 50 micrometers thick — slightly thicker than the aluminum foil found in a kitchen — and can be manufactured economically on rolls, making it a potentially viable large-scale technology for both residential and commercial applications.
“We feel that this low-cost manufacturing process will be transformative for real-world applications of this radiative cooling technology,” said Xiaobo Yin, co-director of the research and an assistant professor who holds dual appointments in CU Boulder’s Department of Mechanical Engineering and the Materials Science and Engineering Program. Yin received DARPA’s Young Faculty Award in 2015.
The material takes advantage of passive radiative cooling, the process by which objects naturally shed heat in the form of infrared radiation, without consuming energy. Thermal radiation provides some natural nighttime cooling and is used for residential cooling in some areas, but daytime cooling has historically been more of a challenge. For a structure exposed to sunlight, even a small amount of directly-absorbed solar energy is enough to negate passive radiation.
The challenge for the CU Boulder researchers, then, was to create a material that could provide a one-two punch: reflect any incoming solar rays back into the atmosphere while still providing a means of escape for infrared radiation. To solve this, the researchers embedded visibly-scattering but infrared-radiant glass microspheres into a polymer film. They then added a thin silver coating underneath in order to achieve maximum spectral reflectance.
“Both the glass-polymer metamaterial formation and the silver coating are manufactured at scale on roll-to-roll processes,” added Ronggui Yang, also a professor of mechanical engineering and a Fellow of the American Society of Mechanical Engineers.
“Just 10 to 20 square meters of this material on the rooftop could nicely cool down a single-family house in summer,” said Gang Tan, an associate professor in the University of Wyoming’s Department of Civil and Architectural Engineering and a co-author of the paper.
In addition to being useful for cooling of buildings and power plants, the material could also help improve the efficiency and lifetime of solar panels. In direct sunlight, panels can overheat to temperatures that hamper their ability to convert solar rays into electricity.
“Just by applying this material to the surface of a solar panel, we can cool the panel and recover an additional one to two percent of solar efficiency,” said Yin. “That makes a big difference at scale.”
The engineers have applied for a patent for the technology and are working with CU Boulder’s Technology Transfer Office to explore potential commercial applications. They plan to create a 200-square-meter “cooling farm” prototype in Boulder in 2017.
“The key advantage of this technology is that it works 24/7 with no electricity or water usage,” said Yang “We’re excited about the opportunity to explore potential uses in the power industry, aerospace, agriculture and more.”
Receive an email update when we add a new RADIATIVE COOLING TECHNOLOGY article.
The Latest on: Radiative cooling technology
via Google News
The Latest on: Radiative cooling technology
- The FIRST type of molecule formed in the universe after the Big Bang is found on April 18, 2019 at 12:26 am
where HeH+ is being formed as a product of matter and radiation from a white dwarf star. Around 13 billion years ago, however, this pioneering molecular bond would have formed as protons first ... […]
- Solar geoengineering: what if countries could move the earth’s thermostat? on April 16, 2019 at 10:27 pm
Solar geoengineering (also known as solar radiation management) is a technology in its infancy – and it is controversial. It has the potential to reverse or mitigate some of the global warming caused ... […]
- Deploying technology in space on April 11, 2019 at 12:02 am
When it comes to radiation the effects are many fold ... the necessary manufacturing techniques to ensure quantum technology is suitable for use in space.” As Murray explains, by cooling atoms and ... […]
- Radiant Heating and Cooling Systems Market to Register Substantial Expansion by 2027 FMI Report on April 10, 2019 at 10:26 pm
Increasing adoption of technology in the radiant heating and cooling market to capture the maximum market share is expected to boost the demand for these systems over the forecast period. Advantages ... […]
- In New Material, Color and Thermal Properties Can Be Tuned Separately on April 4, 2019 at 12:15 pm
April 4, 2019 — Researchers at the Massachusetts Institute of Technology (MIT) have optically engineered ... and passive thermal management through conduction and radiation. To fabricate the films, ... […]
- Best Practices for Radiant Heating and Cooling on March 5, 2019 at 10:30 am
Radiant heating and cooling, an energy-efficient technology popular for net zero energy buildings, is starting to gain acceptance for a wider population of commercial facilities. Two recent studies by ... […]
- CAREER: Investigation of Nanoscale Radiative Heat Transfer for Enhanced Thermal Infrared Energy Conversion and Cooling on February 19, 2019 at 4:00 pm
The fascinating nature of nanoengineered materials has opened the door to novel approaches for conducting research in the field of nanoscale energy conversion and cooling technology. This project ... […]
- The Forecast on Energy-Efficient Cooling Just Got a Bit Sunnier on November 8, 2018 at 2:37 pm
The cooling half of this new technology, pioneered by electrical engineer Shanhui Fan of Stanford University, takes advantage of the natural ability of all objects and organisms to emanate heat ... […]
- Cooling metamaterial scaled up for low power air con on October 29, 2018 at 4:13 am
the technology has now been built out into a functioning cooling system for buildings. The technology, which takes advantage of radiative cooling principles, is described in the journal Joule. “As ... […]
via Bing News