Comparative study of the use of compact heat exchanger or a fin-and-tube coil in a heat pump.

In this paper, we study the use of a compact heat exchanger and a fin-and-tube coil in an air/water heat pump working in cooling mode. Our aim is to analyse these two options and determine the refrigerant charge numerically by using a refrigeration system design program. Firstly, we briefly present the installation constructed to do the study and the test matrix designed to experimentally analyse the system. To do so, we measure enough variables to compute evaporation temperature, condensation temperature, cooling and heating capacities, compressor power consumption, and the COP’s in each case. After, we model the installation with the different two heat exchangers and validate the calculation program. The results corresponding to the previous variables are compared and the refrigerant charge is evaluated. In most cases, a decrease of the refrigerant charge is reported.