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Abstract: The need for air-conditioning in the Mediterranean countries is higher and higher due to the effects of global warming. This paper deals with an investigation of a high performance, solar-driven air-conditioning system, the project entitled “Mediterranean AIRCOND”, is funded by the European Community under the „Community Activities in the Field of the specific program for RTD and demonstration on “Energy, Environment and Sustainable Development”. “AIRCOND” aims to study and investigate performances of advanced solar driven air conditioning system; the field system is composed of three sub systems: the heating loop, the ejector cycle and the cold storage-air handling units: The heating loop is composed of a solar array of 60 square meters evacuated tube solar collectors; installed at a tilt angle of 45o and facing to south, a 3000 L tank which is used as hot water storage in order to cover the required energy by the ejector cycle. The cold water produced by the ejector cycle will be then transferred in a 900L cold storage tank filled with 800L micro-encapsulated phase change material (MEPCM) for cold storage. It is designed to meet the dynamic cooling load. The ejector was tested at the School of the Built Environment in the University of Nottingham in UK and then transferred to Tunisia for field evaluation. Many previous theory studies have been fulfilled on this technology but never been performed experimentally at this level. This paper presents the research effort made and the experience gained during the implementation of the whole system: Different operation strategies were followed during more than one year to make the ejector cycle functional. The whole procedure has turned out to be very difficult; it was particularly difficult to obtain a deep vacuum and to ensure a good vacuum quality; this is a necessary working condition for the ejector cycle. Successful ejector tests were obtained during 8min, 15min and 40min, after many investigations; later experiments led to 3hours of continuous working. Results are very promising; the installation is still under tests in order to obtain a whole day permanent working of the ejector cycle and so of all the solar installation. [Copyright &y& Elsevier]

Abstract: Energy efficient HVAC solutions may be obtained by combining different energy sources – fossil and renewable – into single hybrid systems. This leads to a variety of system concepts with specific boundary conditions. As a consequence, the definition of a unique representation method and a standardized performance evaluation procedure is a challenging task. Currently, two international projects promoted by the IEA are dealing with the representation and the performance calculation of a particular category of hybrid systems, i.e. integrated solar assisted systems. The HPP Annex 34 “Thermally Driven Heat Pumps for Heating and Cooling”, whose goal is to reduce the environmental impact of heating and cooling by the use of thermally driven heat pumps, has solar cooling as one of the systems under investigation. The joint project between SHC and HPP Task 44/Annex 38 “Solar and Heat Pump Systems” is focused on different system combinations of solar thermal collectors and heat pumps. The scope of the present paper is to show a systematic methodology to represent and evaluate the energy performance of complex hybrid systems. The proposed approach is a joint effort of the on-going IEA activities and will be discussed regarding the mentioned solar hybrid systems. However, the final goal of the work is to provide a basis for a simple, fair and transparent comparison of all systems for heating and cooling, regardless of the technology. [Copyright &y& Elsevier]

Abstract: This paper presents the development of a novel solar-powered adsorption cooling tube. The tube consists of adsorbent bed (solar collector), condenser, and evaporator, all in one unit. Activated Carbon-Methanol is used as a working pair to suit cooling and refrigeration applications. From the experimental studies of the tube results all year round, performance and produced cooling are evaluated as well as recommendations and conclusions for best performance are presented [Copyright &y& Elsevier]