Future refrigerants with low global warming potential for residential air conditioning system: a thermodynamic analysis and MCDM tool optimization.

Abstract

Increasing CO2 emission due to the practicing of high global warming potential (GWP) refrigerant like R22 in split air conditioning (AC) units needs the best substitute to match with environment and safety protocols along with good energy efficiency. In this study, 14 alternative refrigerants have been chosen to replace R22 in a 1.5 TR capacity of split AC from the existing studies. The performance of each refrigerant has been analysed thermodynamically and compared their results with R22 by accounting for discharge temperature, power consumption, coefficient of performance (COP), total equivalent warming impact (TEWI) index, and life-time cost. Overall from this theoretical analysis, it was observed that the best refrigerant for each considered measure is not unique; for example, R290 was best in terms of refrigerant charge and discharge pressure, while R444B was chosen to be superior in terms of COP, TEWI, and life-time cost. Therefore, a multi-criteria decision-making methodology tool-based optimization has been carried out for selecting a single superior refrigerant for the future by considering thermal properties, COP, TEWI, and life-time cost. Results of the evaluation based on the distance from average solution envisage R290 and R1123 as superior and worst choices to replace R22.