Improving the cooling system to prevent the water tank from freezing: component optimization for energy efficiency and quality in domestic refrigerators

Abstract

The objective was to implement the 'Material Coverage' methodology to solve this operational problem and optimize inventories. This research addresses the problem of water tank freezing in the Whirlpool French Door Bottom Mount (FDBM) domestic refrigerator model, caused by cold air leaks due to an inadequate thickness of the gasket or foam in the air tower assembly. This issue resulted in inefficient energy consumption and recurrent customer service calls, affecting both cost and product quality. The quantitative methodology, focused on objectivity and numerical data, was structured into phases: Concept Validation, Design Validation, and Process Validation. Rigorous testing was performed in the Thermodynamics Laboratory using thermal chambers, including Energy Baseline, No Load 90, and Pull Down tests, to obtain quantitative data. Control and safety tests, such as Packaging Tests and Material Odour, were also conducted. The main results showed that implementing the new gasket led to an improvement in energy efficiency, achieving a consumption of 618.1 KWh/year. The modified units satisfactorily met temperature specifications in the No Load 90 test and achieved temperature pull-down in an average of 4 hours and 25 minutes, surpassing the 6-hour specification. Factory pre-pilot and pilot events confirmed that the new component assembles quickly and effectively without interference. It is concluded that the hypothesis was accepted, as improving the refrigeration system through the gasket change solved the tank freezing issue, reduced service calls, and optimized the energy efficiency and quality of the FDBM product.