Air-side fouling of finned heat exchangers: Part 1, review and proposed test protocol

Air-side fouling of heat exchangers has received much attention in the literature through both experimental and modeling studies. However, no standards currently exist that define a test procedure to experimentally foul heat exchangers and evaluate their performance in a fouled condition. This is evidenced by the variation in test procedures, fouling agents, metrics, and operating conditions reported. Based on a detailed review of past experiments, a standardized, repeatable test procedure is proposed that allows cross-comparison of data acquired in different laboratory facilities. The procedure generates time-resolved information on foulant buildup on the finned heat exchanger and the consequent impact on heat exchanger performance. Various fouling agents used in the literature and fouling deposits observed on field-installed heat exchangers are compared, and a representative fouling agent is recommended. A method is proposed to quantify heat exchanger fouling and metrics identified to quantify heat exchanger performance before and after fouling. This is the first of two companion papers on an experimental investigation of air-side fouling of heat exchangers. The companion paper presents experimental data obtained by implementation of the proposed procedure to investigate fouling of a finned microchannel heat exchanger.