Evaluation of defrost methods in air-source heat pumps for residential use

The operational efficiency of air-source heat pumps (ASHPs) in residential settings is significantly impacted by the accumulation of frost on their outdoor heat exchangers during colder climates. This phenomenon poses a substantial challenge to their performance, often leading to reduced heating efficiency, increased energy consumption, and potential system malfunctions. The process of defrosting, aimed at mitigating frost buildup, is crucial in maintaining the optimal functionality of ASHPs. This thesis undertakes evaluation of defrost methods utilized in ASHPs. The research delves into the inherent challenges associated with frost accumulation, emphasizing the critical role of effective defrost control mechanisms in enhancing system performance. Realizing the necessity for uninterrupted heat transfer, this study investigates the impact of various defrost strategies on system reliability, energy efficiency, and overall performance in residential environments. The research methodology involves comprehensive field measurements and performance monitoring of ASHPs installed in occupied residential buildings. The data gathered is subjected to rigorous statistical analysis to evaluate the effectiveness of defrost techniques. This evaluation encompasses defrost initiation methods, duration, frequency, and their influence on system energy consumption and heating output. By scrutinizing the operational effectiveness of these defrost control methods, this study aims to address the underlying challenges associated with frost accumulation in ASHPs.