THE IMPACT OF FOULING ON THE PERFORMANCE OF FILTER-EVAPORATOR COMBINATIONS

摘要

This paper presents results of experiments performed on 6 different combinations of filters and evaporator coils under clean and fouled conditions. The fouled conditions were obtained after injection of 600 grams of dust upstream of the filter/coil combination, which was meant to simulate a year of operation in the field. The airside pressure drops of the coils and filters and airside effective heat transfer coefficients of the coils were determined from the measurements under the clean and fouled conditions. Depending upon the filter and coil, the coil pressure drops increased in the range of 6%-30% for an air velocity of 2.54 m/s (500 fpm). The impact was significantly greater for tests performed without a filter. The largest relative effect of fouling on pressure drop occurs for coils with fewer rows, primarily due to higher fin densities. The impact of fouling on airside effective heat transfer coefficients was found to be relatively small. In some cases, heat transfer was actually enhanced due to additional turbulence caused by the presence of dust.