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Energy usually plays a critical role in the development of a country. With the gradual decrease of available traditional fuel reserves and air pollutions problems that being followed by using them, the need to replace alternative renewable and sustainable options to decrease our dependence on fossil fuels has drawn attention. Biomass is a kind of reliable renewable energy that is used to derive combined heat and power systems known as the Organic Rankin Cycle (ORC). This paper presents of exergy analysis of three cycles which have been modeled by EES software for a laundry that needs 32 (kW) power and 2500 (kg/h) 65 (Co) hot water which hot water is our main goal in this study. In RC (gas fuel) and ORC (biomass fuel) power which is produced provides part of electricity needed in the laundry but for Boiler Proving Hot Water (BPHW) the whole electricity needed is bought from the grid. R245fa is a friendly environmentally organic fluid that is used in ORC as a working fluid. The result of this analysis shows for the same conditions the most exergy destruction occurs in the boiler and the least in the pump in three cycles. It also shows the most efficiency of second law respectively is belongs to RC, ORC, BPHW with 0.21%, 0.16%, 9% total efficiency respectively. Moreover, by utilizing EES software and genetic algorithm all of the configurations have been optimized and compared.

The application of phase change materials (PCMs) in green buildings has been increasing rapidly. PCM applications in green buildings include several development models. This paper briefly surveys the recent research and development activities of PCM technology in building applications. Firstly, a basic description of phase change and their principles is provided; the classification and applications of PCMs are also included. Secondly, PCM models in buildings are reviewed and discussed according to the wall, roof, floor, and cooling systems. Finally, conclusions are presented based on the collected data.