Is it possible to keep cool a building in summer without recourse to fans or air conditioning
A team of researchers from Stanford University in California, says that yes, thanks to a new material developed to place on the roof, which has the ability to reflect up to 97% of visible light .
But it also functions as a heat radiator, preventing the building is heated by sunlight and emitting heat into space.
If you cover significant portions of the roof with this mirror you will see how much electricity can save
When the mirror is heated, it releases heat as infrared radiation.
This radiation travels at a longer wavelength than visible light and easily through the atmosphere to reach space.
The researchers believe this wallpaper cooler like a sort of mirror could reduce the amount of energy used to keep cool environment or even make completely unnecessary use of air conditioning.
“If you cover significant portions of the roof with this mirror will see how much electricity can save “explains Shanhui Fan, photonics expert at Stanford University and lead author of the study.
Multiple layers
This mirror, which gave released this week in the journal Nature, is made for several layers of very thin material and has a thickness of 1.8 microns (one micron equals one thousandth of a millimeter).
The first layer is silver, the latter will overlap other silicon oxide and hafnium dioxide.
These layers enhance the ability to reflect the material and transform the mirror on a radiator.
According to its creators, the material structure enables infrared exit directly into space without overheating the space around the building
“We can use the cold darkness of the universe as a renewable thermodynamic resource, even during the hottest part of the day,” the researchers say in the journal Nature.
When they covered the roof of a building this prototype, we managed to reduce the indoor temperature setting 5 ° C.
The roofs are only a very small surface part of the Earth, why not I think this can become a geoengineering solution
Install the mirror can cost between US $ 20 and US $ 70 per square meter, scientists say.
The coating serves to cool buildings, or any other object, for example to prevent overheating by the sun’s heat.
Yet not used to remove heat generated by themselves inside the building.
To do this, scientists believe they could use the mirror to cool water or other fluid, which could then be circulated inside the building.
Global Warming
But, this material has some potential to reduce global warming?
Fan completely rule this idea.
“The roofs are only a very small surface of the Earth lot, so I do not think this can become a solution geoengineering” he said.
“Our contribution to the emission of greenhouse gases is simply to reduce the consumption of electricity.”
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