This material has the potential to eliminate air conditioners more than the electric car to save the planet

The film made of this material can radiate heat from the building to space, realize the temperature control of the building in an ultra low-cost and zero-pollution form, and reduce energy consumption and greenhouse gas emissions.

As part of people’s lives, air conditioning has long been an integral part of modern architecture. But it is air-conditioning that occupies more than 30% of the building's energy consumption. When large amounts of energy are consumed, large amounts of greenhouse gases are emitted, which is arguably one of the major engines of global warming. Is there a way to maintain pleasant indoor temperatures without using air conditioners?

Professor Yang Ronggui and Professor Yin Xiaobo of the University of Colorado at Boulder developed a composite material. The thin film made of this material can emit heat inside the building into the space in a form of radiation. Cost and zero-pollution forms enable temperature control of buildings.

At present, this thin film made of composite materials can already be mass-produced. If it can be promoted to the world, at least 100 million kilowatt-hours of electricity can be saved each year, which will be more effective in controlling the greenhouse effect and the global warming trend.

Cooling the world of black technology

This composite material is a 50-micron thick film made of polymethylpentene randomly embedded in many 8-micron-diameter silica microspheres, which can radiate energy in the form of infrared electromagnetic waves. The effect of cooling. Structurally, this material is similar to irregularly embedded glass balls (silicon dioxide) between a layer of plastic.

The cooling principle of this kind of material is that it can emit the channel in the 8-14 μm wavelength range. The energy emitted in this wavelength range is almost not “converted and digested” by the atmosphere through reflection, absorption, and scattering, but directly passes through. The atmosphere enters outer space. It can be understood that this kind of material is to set up an energy transmission channel between the Earth's room temperature environment and the extremely cold environment of outer space.

By coating a layer of metal such as aluminum or silver on one side of this film, solar reflectance of up to 96% can be achieved, further improving the cooling effect. Experiments have shown that this material has a radiation cooling power of up to 93 W/sq.m. in direct sunlight at noon and can cool objects in contact with it at a temperature of 10-16°C.

More importantly, such a composite material filled with black technology, the manufacturing cost is only 0.5 US dollars per square meter, and can achieve large-scale production. In short, it can be quickly promoted globally.

After promotion, or will substantially reduce greenhouse gas emissions

According to academic statistics, the global use of air conditioners consumes about 1 trillion kilowatt-hours (kWh) of electricity each year, which is more than twice the total energy consumption in the continent and may increase to 10 times by 2050. According to the report of the UN Environment Program, building emissions account for 30% of the annual global greenhouse gas emissions. In the United States, greenhouse gas emissions from commercial and industrial buildings account for 45% of the total.

Professor Yang Ronggui (first from right) and team map | Network

Another set of research data from the United States shows that if the United States can reduce emissions by 10% of buildings, it would be equivalent to reducing the emissions of 49 million vehicles. Note that the total car ownership in Shanghai is only 3.3 million.

Whether it is Hurricane Hurricane that engulfed the United States this year or Hurricane Emma, ​​it is one of the mildest effects of climate warming. As the process of urbanization in developing countries continues, the emissions from their buildings will only increase and will not decrease. The result will inevitably be to further aggravate the rise in global temperatures, which will lead to a more violent natural counterattack.

For the radiation cooling materials developed by Prof. Yang and Yin, no large-scale use cases have yet been seen. However, according to the characteristics of the materials it promotes, it has a special effect in reducing energy consumption in buildings, especially cooling air conditioning. From a purely digital perspective, if large-scale deployments can save a lot of energy and reduce greenhouse gas emissions, it may be more effective than the popularization of electric vehicles in controlling the deterioration of the global climate.