Seasonal energy efficiency ratio of regenerative indirect evaporative coolers—Simplified calculation method

Abstract

Evaporative-cooling technology is a promising alternative to conventional air-cooling systems that are based on using direct expansion units in terms of energy efficiency. Seasonal energy efficiency ratio (SEER) calculation methodologies and standards for these air-cooling systems remain limited. Therefore, the objective of this study is to develop a novel simplified method for calculating the SEER for regenerative indirect evaporative coolers (RIEC). Experimental tests were performed to obtain energy efficiency ratio models of four RIEC systems. Five climate zones in the Mediterranean region were considered for calculation of the SEER values. A detailed calculation method based on annual energy simulations was employed, and the results of the seasonal index were compared with those of a simplified calculation method based on the steady-state operation at four specific test points. The relative error between the SEER calculation methods was 4.6% for all the RIEC systems and climate zones. The highest SEER values of 5.8 and 5.5 were achieved for the Cairo and Madrid weather conditions, respectively. This study can serve as a reference for research on the seasonal performance and life-cycle analysis of RIEC based on an efficient counterflow heat exchanger with a wide range of airflow and cooling capacities.