Investigation of energy and exergy performances of radiant cooling systems in buildings - A design approach

Radiant cooling systems (wall and ceiling) are low exergy systems which can help in solving efficiently the comfort needs of occupants. However, a complex energy and exergy analysis should be done in the design phase of such cooling systems in order to choose the most appropriate solution. This paper attempts to present a mathematical model and methodology of such a complex analysis and illustrates through a case study the energy and exergy comparison of cooling systems with mechanical compression and absorption cooling systems. Simple relations were developed in order to evaluate rapidly the energy and exergy efficiency of these types of cooling systems taking into account the avoidance of surface condensation. It was proven that, besides the coefficient of performances of installed chillers, the temperatures in the generator and absorber, respectively the supply and return temperatures are the main influencing factors of the exergy efficiencies of such types cooling systems. Based on the developed mathematical method a numerical analysis was done assuming different operational parameters of the cooling system used in practice. (C) 2019 Elsevier Ltd. All rights reserved.