Super insulant makes solar refrigerators
Polyurethane foam, 10 cm thick, allows refrigerators to keep contents cool for up to five days without electricity, even at external temperatures of over 40<sup>°</sup>C, and makes solar powered fridges practicable.
Palfridge, based in Swaziland, makes appliances with very thick-walled insulation made of rigid polyurethane foam based on raw materials from Bayer MaterialScience. "Polyurethane insulation has therefore contributed significantly to reducing the energy consumption of refrigerators from 1950 to 2005 by 65 percent", says Robbie Buchanan, an expert for polyurethane insulation at Bayer MaterialScience in South Africa.
Some of the company's product lines are also equipped with two 90 Watt solar modules. "Thanks to these and other measures to boost efficiency, our appliances consume substantially less energy than conventional refrigerators," reveals Roy Singh, Technical Director at Palfridge.
Long-term refrigeration of both food and medicines is essential to many people's survival in Swaziland. More than 25 percent of the population is HIV positive - one of the highest rates anywhere in the world - and therefore dependent on drugs that need to be stored in a cool place, as do drugs to treat malaria.
Palfridge is also first company in Africa to switch its entire production to hydrocarbon as opposed for fluorine containing refrigerants. "This enabled emissions of gases containing fluorine to be reduced by a total of 29,000 metric tons of carbon dioxide equivalents per year. In addition to improving conditions for the people, these measures also make a small contribution to climate protection," continued Roy Singh. The project was financed under the Proklima program of the Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH.
