Even though American chemist Harold Hay (link to bio) was pioneer in the use of water to collect the sun's heat and then use it to heat homes in his Skytherm House, what the Argentine scientist has added is the water redistribution and low cost factors. "Traditional solar collectors require high investments, what I'm proposing is a roof whose cost is near to the one of a conventional roof and which can provide heating and cooling by water redistribution and therefore save energy," says the scientist in the presentation of the project.
Picture: Luis Juanico (white shirt) and his team at his office in Bariloche, Patagonia (Rio Negro newspaper).The roof is conformed of a water pond, and two glass isolators with an air chamber in between; and it is covered by a scrollable curtain. During winter days, the curtain is scrolled out for the roof to absorb the sun's radiation, which gives direct heat to the house and heats the water inside the pond. Through an outlet, the hot water is stored in a tank. At night, with the curtain scrolled out the house gets isolation and at the same time, the hot stored water is sent to the heating in-floor system.
During the summer, the process is backwards: the roof remains uncovered during the night to cool the water which then will be used during the day to cool the in-floor system, while the curtain remains covering the roof to avoid the sun's radiation.
The mentioned curtain is actually a rolling awning (not foldable) also designed by Juanico, and is configurable to be opaque, transparent and open mesh, according to the needs.
"As pioneers like Harold Hay have shown, it is possible to obtain very good results by means of configurable designs, adaptable to the environment. These two new configurable designs could help us modify the deeply rooted paradigm of the classic roof and building," says Juanico at the end of his project presentation.
The cost of the roof is the same of a good quality roof: 100 US dollars the square meter, informs the presentation of the project.
The configurable solar roof received the first prize of the technical contest at the International BIEL Light & Building Buenos Aires congress in 2007 and will be published in the Solar Energy magazine. It is being tested at El Bolson, in Patagonia. For more information, see the PDF presentation of the project from the BIEL website or write an e-mail to Luis Juanico (juanico [at] cab [dot] cnea [dot] gov [dot] ar. ::Configurable Solar Roof Presentation
Scheme that shows the functioning of the roof on a winter day.
Graphic for the functioning on a winter night.