A solar cooled air-conditioning system
Spanish scientists have developed a new eco-friendly air-conditioning system. The researchers are relying on solar energy for cooling their devices. They claim that their technology does not harm the ozone layer and reduces the use of greenhouse gases. The research team has 'designed and built an absorption chiller capable of using solar and residual heat as an energy source to drive the cooling system.' Even if this research effort looks promising, the scientists don't provide any information about availability or pricing for such devices. But read more...
As you can see above, this solar cooled air-conditioning system looks like an ordinary air-conditioning one. (Credit: Marcelo Izquierdo Millán and his colleagues) Here is a link to a larger version of the above illustration.
This research work has been led by Marcelo Izquierdo Millán, an Associate Professor from the Department of Thermal Engineering and Fluid Mechanics of the Universidad Carlos III de Madrid (UC3M). He also is a researcher at the Eduardo Torroja Institute for Construction Science (IETCC) of the Consejo Superior de Investigaciones Científicas (CSIC, or Spanish National Research Council).
So what Izquierdo and his colleagues are developing? They're "building a solar cooling system that unlike the existing machines on the market, uses an improved absorption mechanism capable of producing cold water at a range of temperatures from 7º C to 18º C when the exterior temperature ranges from 33º C to 43º C. Professor Marcelo Izquierdo states that the conclusions reached by a study with a commercial air condensed absorption machine prove that given an outside temperature ranging from 28ºC and 34ºC, the machine can produce cold water at a range of 12 to 16ºC, with a source temperature at the generator between 80ºC to 95ºC."
Here are additional details provided by Raquel Lizarte, a researcher at UC3M. "'There are few absorption machines at a commercial level that are adapted for residential use,' and since it is very hard to go without climate control, it is important to find a cooling technology that has minimal environmental impact. 'The machine that we're studying produces enough cold water to cool down a room of 40 m2 of floor area and with a volume of 120 m3,' she states."
For those of you who understand Spanish, please note that the AlphaGalileo document I've mentioned in the introduction of this post has been published on July 14, 2008. But the original UC3M news release, "El frío solar, un nuevo sistema de refrigeración," was issued on June 2, 2008. AlphaGalileo's motto is "The world's leading resource for European research news." So why did we have to wait six weeks for a translation? Anyway, thanks to AlphaGalileo people.
Izquierdo's latest research work has been published in the scientific journal Applied Thermal Engineering under the title "Air conditioning using an air-cooled single effect lithium bromide absorption chiller: Results of a trial conducted in Madrid in August 2005" (Volume 28, Issues 8-9, Pages 1074-1081, June 2008).
Here is the beginning of the abstract. "Trials were conducted to determine the performance of a commercial (Rotartica 045v) 4.5-kW air-cooled, single effect LiBr/H2O absorption chiller for residential use. The experiments were run at La Poveda, Arganda del Rey, Madrid, in August 2005. Three typical August days, with different outdoor temperatures, were chosen for the study. The hot water inlet temperature in the generator varied throughout the day from 80 to 107 °C."
For more information, you can read a document written in Spanish by Marcelo Izquierdo Millán in March 2004, "Refrigeración Solar En La Edificación: Presente Y Futuro" (PDF format, 22 pages, 1.02 MB). Even if you don't understand the Spanish language, you can take a look at a diagram on page 8 showing an early prototype of this system using a lithium bromide solution.
Sources: Universidad Carlos III de Madrid, Spain, via AlphaGalileo, July 14, 2008; and various websites
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