'Breathable' Metal Could Usurp Air Conditioning
With its pores and sweat glands, human skin might be one of world’s best natural air conditioners.
“It has all these things that work together very dynamically and efficiently. And so what I propose is that our building skins should be more similar to human skin,” biologist turned architect, Doris Kim Sung, said in her TED talk last October.
Considering that 30 to 40 percent of all primary energy consumed worldwide goes toward heating and cooling buildings, Sung’s sustainable design concept could be a more passive method for ventilating buildings. Better yet, the material she plans to use has been around for 100 years and is so simple, she couldn’t understand why no one had used it yet for this idea.
The material she has in mind is a thermo-bimetal strip — two thin pieces of metal such as copper and steel sandwiched together. These two metals expand and contract when heated and cooled. When it’s hot, the metal bends one way. When it’s cold, it bends the other.
Sung has two main concepts in mind for the bimetal. Both would require no additional energy other than the sun, a concept know as ‘passive solar’ in architectural speak.
“I’m proposing to use it on the skin of buildings for a few different purposes. One is as an automatic sun-shading screen and the second basic application is for ventilation as a way to release hot air from the building,” she said, according to Humans Invent.
When direct sunlight hits the bimetal strips, they would bend inwards and close together to shade the building. Anyone who’s been in a glass building in mid-summer knows how they trap the sun’s heat. This first application would help alleviate that. Conversely, when the building gets too hot, the metal could bend in such way that opens up “pores” to release heat.
“I don’t know if we will ever get to the point where we can truly be rid of air conditioning, especially in certain parts of the world, but the definite hope is to reduce the necessity to require air conditioning,” Sung said. “It is trying to move to a more holistic way of building architecture. If we could reduce the amount of air conditioning or heating used just by making buildings more passively designed then we have saved a lot for buildings.”
Credit: Doris Kim Sung