Media Releases

Bio-inspired design may lead to more energy efficient windows

August 2, 2013

TORONTO, ON – Uni­ver­si­ty of Toron­to Engi­neer­ing pro­fes­sor Ben Hat­ton is turn­ing to nature to find a way to cut down on the ener­gy leaks from win­dows.

In a recent arti­cle in Solar Ener­gy Mate­ri­als & Solar Cells, Hat­ton and his col­leagues at Har­vard Uni­ver­si­ty describe a nov­el process to cut down on heat loss dur­ing the win­ter and keep build­ings cool dur­ing the sum­mer.  Their “bio-inspired approach to ther­mal con­trol for cool­ing (or heat­ing) build­ing win­dow sur­faces” calls for attach­ing opti­cal­ly clear, flex­i­ble elas­tomer sheets, bond­ed to reg­u­lar glass win­dow panes. The elas­tomer sheets have chan­nels run­ning through them through which room tem­per­a­ture water flows.

The tech­nique has result­ed in sev­en to nine degrees of cool­ing in lab­o­ra­to­ry exper­i­ments and is effec­tive both at small and large scales, Hat­ton and his col­leagues said.

“Our results show that an arti­fi­cial vas­cu­lar net­work with­in a trans­par­ent lay­er, com­posed of chan­nels on the microm­e­ter to mil­lime­ter scale, and extend­ing over the sur­face of a win­dow, offers an addi­tion­al and nov­el cool­ing mech­a­nism for build­ing win­dows and a new ther­mal con­trol tool for build­ing design,” he said.

Hat­ton not­ed that win­dows account for about 40 per cent of build­ing ener­gy costs. To find a solu­tion to the prob­lem, he turned to nature. “In con­trast to man-made ther­mal con­trol sys­tems, liv­ing organ­isms have evolved an entire­ly dif­fer­ent and high­ly effi­cient mech­a­nism to con­trol tem­per­a­ture that is based on the design of inter­nal vas­cu­lar net­works. For exam­ple, blood ves­sels dilate to increase blood flow close to the skin sur­face to increase con­vec­tive heat trans­fer, where­as they con­strict and lim­it flow when our skin is exposed to cold.”

He said the tech­nique could also be applied to solar pan­els, increas­ing their effi­cien­cy. He also not­ed that as the water flows through the pan­els, it gets hot­ter, and this hot water could be used to sup­ply heat­ed water to an exist­ing hot water sys­tem or to a heat stor­age sys­tem.


For more infor­ma­tion, con­tact:

Ter­ry Laven­der
Com­mu­ni­ca­tions & Media Rela­tions Strate­gist
Fac­ul­ty of Applied Sci­ence & Engi­neer­ing, Uni­ver­si­ty of Toron­to
Tel: 416–978-4498