Air-side fouling of finned heat exchangers: Part 2, experimental investigation and assessment of test protocol

An experimental test protocol for simulating the air-side fouling of heat exchangers, as well as metrics to characterize the extent of fouling undergone by the heat exchanger and its performance in clean and fouled conditions, were proposed in a companion paper. In this study, the air-side fouling of a finned microchannel heat exchanger is experimentally investigated according to the proposed protocol. Key test parameters influencing heat exchanger fouling are identified based on studies in the literature, and their impact is experimentally investigated. The effectiveness of in situ cleaning methods is also experimentally evaluated. Transient measurement data and photographs taken during the fouling process reveal the nature of fouling, while steady-state data quantify the degradation in heat exchanger performance due to fouling. This two-part study defines a generalized experimental approach to enable characterization and comparison of heat exchanger surfaces on a standardized basis, and provides detailed experimental data for modeling heat exchanger fouling that includes all necessary information to allow for model validation.