In an attempt to reduce energy consumption, a team from the University of Colorado developed a radiative cooling material. The translucent metamaterial film that was to be used would feature the ability to cool a home at the expense of zero energy. If the plan worked out well, it would help a long way in reducing the large energy bills accelerated by old-fashioned air conditioning units in the summer in Arizona, southern California and Florida.
The old-fashioned machines used in air conditioning were the split system and air-source air conditioning. There was another type that worked by a simple cooling mechanism; the heat from the indoor air went into the cold coil. The coil was filled with a refrigerant, a material that can get cold such as Freon. After the indoor heat is absorbed, the refrigerant is transmitted to the outdoor unit (in a typical split system). Heat is released to the atmosphere through the application of a coil and compressor. These obsolete systems have since been replaced by the more effective modern units.
The research on the translucent metamaterial film was conducted by the University of Colorado in the materials science and engineering department, mechanical engineering department, and aerospace engineering and sciences partnered by another group from the University of Wyoming. The study was published in the journal known as Science, and explained that passive radiative cooling usually removes heat from surfaces, and then radiates it into the atmosphere as infrared. The only challenge was finding a suitable material for handling solar irradiance. Again, it was difficult to find a material that would as well handle low infrared radiation flux’s energy density mismatch.
The research explained how the teams had attached resonant polar dielectric microspheres in a polymeric matrix randomly and had got a metamaterial fully transparent to the solar spectrum. During this, the material is required to have an infrared emission that exceeds 0.93 across the atmospheric window. When the material was backed with silver coating, it showed a noontime radiative cooling power of 93 W/m2 under direct solar radiation. Both high throughput and economic roll-to-roll manufacturing of the metamaterial were proven, which was important in promoting radiative cooling. This would be a substantial addition to energy technology.
The translucent film developed by the team contained tiny silicon dioxide spheres that would help release any infrared radiation and simultaneously deny the absorption of any sunlight energy. This happened by the material letting any solar radiation move through it, and on the other side, a reflector placed to relay the radiation away. Once installed in a home, no energy would be required to do the air conditioning job.
This research, however, concerns a relatively uncharted industry. Those who had previously developed similar radiative cooling solutions in the past found a workable system, which was expensive and difficult to scale. The scalability of this project is not known, making it hard to make assumptions of the project as per now. With the introduction of technology in the air conditioning industry, the future looks bright for residents and businesspersons.
