The negative influence of refrigerants on the climate and the immediate environment in terms of their higher global warming potential (GWP) and ozone depletion potential (ODP) has prompted this study. Currently, natural refrigerants are the preferred alternative refrigerants and hydrocarbon is numbered among these natural refrigerants with zero ODP and negligible GWP. In order to improve and enhance the performance of the refrigeration system, the performance characteristics of the system were investigated experimentally using eco-friendly refrigerant HC600a as alternative to HFC134a. In addition, comparisons were made using refrigerant mass charge of 46 g of isobutane (HC600a) and 70 g of conventional refrigerant (HFC134a). Thermodynamic parametric analysis was conducted using electric power consumption, coefficient of performance (COP), cooling load and pull-down time (PDT) for the used mass charges. REFPROP software was applied to capture the thermodynamic properties of the vapour compression system (VCS). The results showed that the COP increased by 32.2 % when using 46g charge of hydrocarbon refrigerant with energy reduction of 4.5 %. Furthermore, the vapour compression system while using 46 g of isobutane (HC600a) attained an evaporating temperature of -21 °C in 60 minutes while 70 g of HFC134a attained the same temperature in 2 hours 15 minutes, which makes HC600a alternative refrigerant to run in the traditional refrigerator.

This paper presents performance analysis of a domestic refrigeration system using R600a as refrigerant. Investigation was conducted experimentally to select an appropriate refrigerant mass charge for the system and to compute the cooling system performance characteristics under ambient temperature of 29°C. The choice of the hydrocarbon refrigerant (R600a) became so imperative due to notable influence of chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) on global warming and ozone depletion. UNFCCC and Montreal Protocol regulation have banned the use of halogenated refrigerants in cooling and heating systems. The paper reveals that the power consumed by the system using mass charge of 15 g refrigerant was reduced by 9.3 and 10.9% compared with the 10 and 25 g refrigerant mass charges respectively. In addition, the results show that the coefficient of performance (COP) of the refrigeration system while working with 15 g is 24.7 and 20.2% higher than when the system worked with 10 and 25 g refrigerants mass charge respectively. More so, the system attained an evaporator air temperature of -12 °C in 2 hours, which makes 15 g charge refrigerant appropriate for the running of the developed system that has a volume capacity of 68 liters.