Performance-cost and global warming assessments of two residential scale solar cooling systems versus a conventional one in hot arid areas

In this study, performance evaluation, energy efficiency, cost competitiveness and global warming assessments of residential scale solar thermal, a silica gel-water adsorption chiller, air-conditioning system versus a conventional system in hot, arid areas is carried out. This has been done throughout an applied research project with site measurements in which the two cooling systems were designed, build and operated at Assiut, Egypt with both systems has a nominal cooling capacity of 8 kW. In addition, a comparison with an off-grid PV driven direct current (DC) with 8 kW air cooling conditioning system is made with the above two systems. The comparison is based on the lifespan of 20 years and 18 h' daily operation during the cooling session. The experimental results show that the indoor thermal comfort conditions are achieved in the hottest days of the year for an area of an 80-meter square with 14 occupants and lab equipment. From the results, clearly, the solar thermal driven cooling system has an energy consumption of 10.94%, with Total Equivalent Warming Impact (TEWI) of 9.96% and total cost per kW cooling of 295.96% compared with the conventional vapor AC driven air-conditioning system. While, the off-grid PV driven air conditioning system has 0% energy consumption from the grid with TEWI value of 0.648% and total cost per kW cooling of 54.88%, respectively. Therefore, the off-grid PV driven DC air conditioning system can be recommending for use in residential sector application in hot, arid areas based on its low cost per kW cooling, zero grid energy consumption, and very low Total Equivalent Warming Impact value. (C) 2017 Elsevier Ltd. All rights reserved.