New frost property correlations for a flat-finned-tube heat exchanger

This paper discusses the fundamentals of experimental techniques for frost measurements and presents unique frost property correlations that are developed from experiments on a lab-scale flat-finned-tube heat exchanger. A multilinear regression analysis was employed on air inlet temperature and humidity ratio, frost-coil interface temperature, refrigerant inlet temperature, and Reynolds and Fourier numbers. This resulted in the development of mathematical expressions for frost thickness, density, thermal conductivity and air pressure drop across the heat exchanger. The newly developed correlations will be useful for better prediction and control of defrost periods and duration for medium-temperature (−10 °C) air coils.