A comparative study of plate-fin and tube-fin heat exchangers based on thermal data experimentally collected from an air-conditioning unit

Compact heat exchangers are commonly used for many refrigerating and air-conditioning applications due to features like high performance and less space consumption. The objective of this paper is to provide an overview of the salient features of tube-fin and plate-fin compact heat exchangers and hint at conditions when to select either of them as per the application demand. A sample air-conditioning unit of heat capacity 2.63kW is used to perform an experiment in order to collect 40 sample readings. These readings are used to develop the system's Pressure-Enthalpy chart to calculate the condensing heat load, and then only the condenser is redesigned from tube-fin to plate-fin configuration. The final result in terms of the sizes and weights of both the condensers are compared and the conclusion is derived. The pressure loss in the tube-fin condenser is determined using Lockhart-Martinelli and Geary's equations, which are validated against a renowned air-cooler design software- Unilab Coils. During the design of the new proposed plate-fin condenser, suitable correlations are used to find the heat transfer and pressure loss coefficients. These coefficient values are also verified against another popular software named Aspen EDR which falls within an acceptable range. The results of this comparative study could not be generalized, as it requires more investigation to be conducted over wide heat load capacities, however, it proves salient features of studied heat exchanger types. It also improves the decision-making capability of thermal engineers or related field practitioners on the type of selection of exchangers for certain applications.