Study of the Performances of a Residential Air Conditioner Converted respectively to Propane and Isobutane in Tropical Conditions

Abstract

Refrigeration and air conditioning are often incriminated for their contributions to the greenhouse effect. An alternative solution to curb this problem is the use of refrigerant with low global warming potential (GWP). To meet this goal, most hydrocarbons are potential candidates. Thus, the objective of this work is to compare the energy performance of propane (R290) and isobutane (R600a), which are low GWP fluids used as refrigerants in a residential split air conditioner under tropical climatic conditions (typical case of Benin). The investigation aimed to analyse the thermodynamic performance of these two fluids from their refrigeration cycles. The studies were conducted on a residential split air conditioner in Benin converted respectively to R290 and R600a refrigerants. The air conditioner was charged in increments of 50g of refrigerant until reaching the maximum load of 400g. Series of measurements (of temperature, hygrometry, air velocity, and mass of fluid, pressure, current intensity and voltage) were performed to calculate the cooling capacity and the coefficient of performance for each load of refrigerant. The so-named Engineering Equation Solver and MATLAB software were also used to simulate the performance of the studied fluids.  The results of the study showed that the best operation conditions are guaranteed for a charge of refrigerant comprises within 150g and 300g for both fluids. The equipment showed better performances with R600a.