Para aqueles que nunca ouviram falar sobre o “krill”, ele é o nome coletivo dado a um conjunto de espécies de animais invertebrados e muito semelhantes ao camarão.

Segundo ainda a Wikipédia, estes pequenos crustáceos são extremamente importantes organismos do zooplâncton, especialmente porque servem de alimento a baleias e outros mamíferos aquáticos, além de peixes e outras espécies. Na realidade, estas pequenas criaturas ocupam o que se pode chamar de “fundo” da cadeia alimentar.

No entanto, alguns pesquisadores de Harvard têm estudado uma interessante característica destes pequenos seres, no que tange a sua capacidade natural de controlar o efeito do sol em sua pele, através de minúsculos pigmentos que alteram a sua cor (para o alaranjado), assim que percebem a incidência dos raios solares. Este interesse dos pesquisadores se deve ao fato de que nos EUA, por exemplo, 40% de toda a emissão de gases causadores do efeito estufa se originam a partir do uso de sistemas prediais em edifícios, como o aquecimento, a climatização e sistemas de iluminação.

Adiciona-se a esta preocupação a vital influência de fachadas nestes edifícios sobre tais desempenhos destes sistemas, razão pela qual os modelos de certificação de edifícios sustentáveis têm se atido a este cuidado, através de pontos específicos em suas respectivas normas.

Os pesquisadores acreditam ser possível aprender com a evolução natural destes pequenos seres vivos, desenvolvendo uma tecnologia que complemente os nossos modelos construtivos de fachadas, reduzindo substancialmente o impacto dos raios solares e, consequentemente, da sobrecarga exercida sobre os sistemas prediais e a geração de gases que promovem o efeito estufa.

O artigo está em inglês, mas é muito interessante ao narrar, ainda que de forma sucinta, a tese desenvolvida por este grupo de pesquisadores em Harvard. A matéria foi publicada pela BLOOMBERG – US EDITION e recentemente compartilhada pela ASHRAE em seus jornais periódicos.

Recomendo a sua leitura não somente aos apaixonados por projetos sustentáveis, como também àqueles que buscam por atualizações em relação as novas tecnologias da construção.

Navigator: The Krill Building

Fonte (Source): Bloomberg – US Edition

Por (By): Sarah Holder

Click here to read this article directly from its source.

Welcome to today’s edition of Navigator, CityLab’s biweekly Saturday newsletter.

You may know krill for their role as whale food. Most stories about these teeny shrimp-like crustaceans are told from the perspective of their many predators; they live near the bottom of the ocean food chain and get devoured in huge numbers by fish, seabirds and marine mammals. (A blue whale can inhale 16 tons of the microscopic decapods daily.) But krill are complex creatures in their own right. And they may have a lot to teach us about how to make buildings more energy-efficient.

In a recent paper published in Nature, a group of University of Toronto researchers propose adapting an HVAC technique from Antarctic krill, which use pigments stored in their skin to protect themselves from the sun. They’re developing a product that could do something similar for building facades. In the US, 40% of all greenhouse gas emissions come from buildings and their associated heating, cooling and lighting systems. 

“If we could learn from biological organisms that keep their ‘indoor environments’ comfortable much, much more efficiently using techniques that they’ve evolutionarily developed over millions of years, maybe we could make our built infrastructure at least a fraction as efficient,” says Raphael Kay, the lead author on the paper and now a research fellow at Harvard’s school of engineering. 

Krill store sacs of pigment in their skin that allow them to instantly change color from white to orange, acting like highly responsive curtains. “When they sense that the sunlight level is too high,” says Kay, “they will send a signal from the brain to these tiny little dots of pigment, saying, ‘Un-clump yourself,’ basically.”

Kay and his team want to apply this principle to buildings by making windows filled with two types of fluid: one that absorbs sunlight, and another that allows it pass through. 

“When the window doesn’t have any pigments in it, it looks like a regular window,” Kay says, “except secretly there’s a layer of fluid in it that lets sunlight come in.” To block sunlight, pigmented fluid is injected through tubes, dispersing through the skin of a skyscraper and allowing the building to keep cool, krill-style. The authors speculate that such a system could be cheaper and more efficient than current “active shading” methods being developed for green buildings.

Looking to the nature for engineering inspiration is as old as technology itself, but such biomimetic design is particularly hot right now — architects are borrowing from trees, termite mounds and polar bears in search of better ways to build. I personally am excited about looking up to see a ton of apartment buildings with windows oozing like a lava lamp. (Kay says there’s the potential to introduce different colors at different times of day, to link up to our circadian rhythms.)

But even more exciting to the researchers are the environmental implications of having digitally controlled, finely tuned solar shades that cost very little to install. In their models, they say energy consumption was reduced by more than 30%.

Thanks, krill!