The Effect of Water Mass on Freezing Time Using a ½ HP Outdoor Air Conditioner Unit

Abstract

The growing demand for ice production in tropical regions necessitates the development of efficient and cost-effective refrigeration systems. This study examines the effect of water mass variation (5 kg, 10 kg, and 15 kg) on the performance of an ice-making machine utilizing an outdoor air conditioning unit (½ PK). The system operates based on the Vapor-Compression Refrigeration Cycle, employing a serpentine evaporator immersed in a 20% saline solution. The experimental results indicate that freezing time increases proportionally with water mass, reaching 2.5 hours for 5 kg, 3.5 hours for 10 kg, and 5 hours for 15 kg. Heat transfer analysis shows that although the total thermal load rises with increasing mass, the system gradually approaches its cooling capacity limit, leading to reduced performance improvement at higher loads. Statistical evaluation using error bar analysis further confirms significant differences between lower and higher mass variations. From an economic perspective, the findings demonstrate that on-site ice production is considerably more cost-effective than purchasing ice, with unit costs decreasing as production volume increases. However, a trade-off emerges between cost efficiency and processing time. Therefore, optimizing the performance of ice-making systems requires a balanced consideration of thermal efficiency, system capacity, and economic viability.

Keywords: heat transfer, Ice-making machine, Water mass variation, Freezing time, Vapor-Compression Refrigeration Cycle, Economic analysis, Refrigeration system