Design and application of evaporative cooler for a freezer

•EC was used to cool the compressor of freezer to improve the freezer performance.•The EC was constructed using a MTQDT to provide superior evaporative cooling.•The performance tests were conducted to evaluate the freezer with and without the EC.•EC could effectively reduce the Tcase and Tdis of the freezer’s compressor.•The Rtr and EF with the EC was −2.36% and 1.54% compared with the original machine. In this study, a self-designed evaporative cooler (EC) was used to coat the compressor of an R404A freezer (internal volume: 540 L) to cool the compressor through evaporative cooling and thus to improve the freezer performance. The EC was constructed using a moisture-transferring and quick-drying textile (MTQDT) to provide superior evaporative cooling. The unloaded pull-down, loaded pull-down, and 24-h on-load cycling characteristics of the freezer were measured under different ambient temperatures and relative humidity conditions (27 °C/70% RH, 30 °C/70% RH, and 35 °C/75% RH) to evaluate the freezer performance with and without the EC. The results showed that the installation of the EC could effectively reduce the case temperature (Tcase) and discharge temperature (Tdis) of the compressor and improve the slope of pull down (SPD) for the freezer temperature (Tf) and coefficient of performance (COP) of the freezer. The effects of the EC on Tcase, Tdis, SPD of Tf, and SPD of COP during the pull-down tests were enhanced by increasing the ambient temperature (Ta). Tcase, Tdis, SPD of Tf, and SPD of COP of the freezer with an EC were −5.99 °C, −4.89 °C, 7.36%, and 15.06% and −5.44 °C, −4.37 °C, 7.19%, and 14.73% compared with those of the original machine in the unloaded pull-down and loaded pull-down tests at a Ta value of 35 °C, respectively. In addition, in terms of the 24-h on-load cycling test results, the difference ratio of the operating time of the compressor (Rtr) and energy factor of the freezer (EF) with the EC was −2.36% and 1.54% compared with those of the original machine at a Ta value of 35 °C.