Comparison between a simple solar collector accumulator and a conventionalaccumulator

In dry regions with abundant solar radiation at Southern latitudes between 30 and 40 degrees, such as the central-western part of Argentina, it is pos sible to obtain domestic hot water by means of simple integral collector ac cumulator systems, which are less expensive than the classical flat plate a ctive systems. The experimental assessment of two solar accumulator collect or systems yielding 300 l of hot water daily is reported in this work. Dail y diurnal global efficiency and nocturnal thermal losses have been systemat ically determined over a 5-month period, from austral summer to austral win ter. The results of these systems were compared with the results obtained f rom a high quality thermosyphon solar system composed of a flat plate colle ctor and its corresponding insulated storage tank. tested at the same time. The experiments were carried out by measuring the climatic variables, temp eratures in different parts of the collectors, and mass flow rates of water . during the test days. Based on these measurements, the behaviour of the s ystems was analysed by comparing exit temperatures, heat losses, and delive red useful energy. An economic evaluation was made considering the investme nt time recovery through the savings the system could provide working with different conventional sources, of energy. The systems proved to work effic iently, although some improvements should be made on the se mi transparent thermal insulation in order to enhance its winter performance. (C) 2001 Els evier Science Ltd. All rights reserved.