Experimental studies on the performance improvement of household refrigerator connected to domestic water system with a water-cooled condenser in tropical regions

•Residential water supply system to cool the condenser of household refrigerator.•Water-cooled condenser saves 21 to 27 percent energy in household refrigerator.•Brazed plate heat exchanger improves the energy efficiency of household refrigerator.•Water-cooled condenser reduces the TEWI of domestic refrigerators. The consumption of electrical and thermal energies in the residential building sector is growing fast and many strategies are being followed to overcome the energy demand in this sector. Among the various strategies, performance enhancement of refrigeration systems has been identified as one of the important areas for investigation. Due to the increase in the use of small-scale appliances and their impact on global energy requirements, specific research has to be focused on small scale systems with water-cooled condensers to reduce the energy consumption in residential buildings. In this study, the water-cooled condenser of a refrigeration system was connected to the prevailing water distribution system of a house with suitable changes in the existing arrangements. The proposed system was analysed for energy savings and environmental benefits. The experimental work was conducted in the tropical region, and the experimental findings indicated that the brazed plate condenser in small-scale refrigeration systems could decrease 21 to 27% of daily energy consumption. The total equivalent warming impact was found as 26.8% lower than that of conventional systems. Among the refrigerants, R290/R600a (45.2:54.8 – mass percentage) mixture showed 5.9% lower per day energy consumption and 8.9% higher COP than that of R134a. Compared to R134a, the R1234yf showed an increase of 4.7% and 7.3% in per day energy consumption and pull-down time respectively for all tested conditions. However, this small reduction in the performance of R1234yf may be tackled by optimizing the system components. Thus the building energy-efficiency could be improved by integrating the household refrigerator with the use of general water supply in a residential building.