Design study comparison of plain finned versus louvered finned-tube condenser heat exchangers

Enhanced fins are widely used in residential air conditioning system finned-tube condenser designs. While this heat transfer augmentation technique increases the heat transfer coefficient in the heat exchanger, it also increases the air side frictional pressure drop. These two effects compete with each other, making it difficult to determine the relative goodness between plain fin versus enhanced fin designs with realistic constraints. In the past, this design tradeoff has been largely determined by experimental trial and error or heuristic figures of merit. No studies are available showing the effect of fin augmentation on overall system performance under consistent cost and frontal area constraints. The residential air conditioning system model calculates all component and system performance parameters. The condenser design requires the specification of approximately ten design parameters. A search method is used to vary these ten parameters and reach an optimum design based on a COP (efficiency) figure-of-merit with condenser cost and other appropriate constraints. It was found that when optimized, louvered fin designs always show better system performance than the optimum plain fin design for the cases studied. However a decrease in system efficiency can result if louvers are merely added to a plain fin optimum design.