Integration of Phase Change Materials (PCMs) in Freezer of a Domestic Refrigerator: A Comparative Study

Temperature fluctuation in the refrigerator affects the freshness and shelf life of the food. Integration of phase change material (PCM), which facilitates high thermal energy storage capability, is one of the effective ways to subside the shelf temperature fluctuation and reduce the compressor ON/OFF cycles. An in-house experimental test facility is developed to test the performance of a 200-L storage capacity non-frost-free domestic refrigerator by integrating the designed mass of the chosen PCMs, salt solution (10% NaCl + 90% H2O by wt.) and eutectic solution (25% C2H6O2 + 75% H2O by vol.), in the freezer compartment. Operating the refrigerator at higher thermostat position increases the running time and eventually increases the ON/OFF ratio of the compressor and consequently higher energy consumption, about 0.9 kWh/day at the highest position of thermostat. Using PCM reduces the compressor ON/OFF cycle significantly, about 50–80% in comparison with without PCM; however, a compressor ON/OFF ratio almost remains same. Cut-out temperature decreases considerably with PCM, by about 4 °C with salt solution and 3 °C with eutectic solution compared to without PCM. PCM slows down rate of rise in temperature and helps to keep the freezer temperature lower for longer duration during power cut. © 2023, The Institution of Engineers (India).