Comparative Experimental Study of Grid and Helical Condenser Coils in a Vapour Compression Refrigeration System Using R-600a

The performance of a vapour compression refrigeration (VCR) system is significantly influenced by the design of its condenser. In the present work, a comparative experimental study is carried out to evaluate the performance of a conventional grid-type condenser and a modified helical coil condenser in a domestic refrigeration system. The system is operated using R-600a, an environmentally friendly refrigerant with low global warming potential. Helical condensers of different coil diameters (200 mm and 250 mm) are fabricated and tested under identical operating conditions. The performance of the system is analyzed in terms of key parameters such as net refrigeration effect, work of compression, compressor power consumption, and coefficient of performance (COP). The experimental results indicate that the helical condenser configuration enhances heat transfer characteristics due to increased surface area and the presence of secondary flow effects. Among the configurations tested, the 250 mm diameter helical condenser exhibits superior performance, with an increase in COP from 1.82 for the existing system to 2.40, along with a reduction in compressor power consumption from 1.92 kW to 1.65 kW. The results demonstrate that the use of a helical condenser significantly improves the energy efficiency of the refrigeration system. The study highlights the effectiveness of condenser geometry modification and supports the use of R-600a as a viable and eco-friendly alternative refrigerant.