Study on the heat transfer with regard to an off-grid vending machine having a low impact on the environment

Abstract

Following the current trend of energy economy, the article’s team designed a vending machine made of sandwich panels, in order to minimize the heat transfer from the environment to the chilled volume. The heat inputs calculation was based on the data provided in the sandwich panels’ technical sheets. In this paper, the real performance in operation was monitored, resulting in a deviation between 2.27 and 5.37% of the theoretical values for the global heat transfer coefficient. Furthermore, the TEWI coefficient (Total Equivalent Warming Impact) was evaluated to highlight the energy efficiency of the equipment, operating with refrigerant R290. Thereby, the authors emphasize the importance of the transition to natural refrigerants.