A comparison of the predicted and experimental heat transfer performance of a finned tube evaporator

Experimental data have been generated for a single-circuit, multi-pass finned tube heat exchanger representative of an element of a typical packaged air conditioning unit evaporator. The data have been used to validate a cross flow heat exchanger computer program (ACOL5), developed originally for large scale steam plant, for air conditioning applications. The tests were conducted for a wide range of spatially uniform air flow conditions on to the coil, together with a variety of R22 refrigerant entry dryness fractions. The correspondence between the predicted and experimental heat transfer performance was good, thus suggesting that the program could be used with a degree of confidence in the design of air conditioning and refrigerant equipment. A particular application is that of prediction of the effects of maldistribution of air flow through heat exchangers, a common cause of loss of efficiency in air conditioning and refrigeration units; this topic is addressed in a companion paper.