Methods for comparison of refrigerants
Comparing refrigerants has to be done carefully to get a useful and technically neutral, unbiased result. Think about the importance, as the choice of refrigerant is one of the first things to be fixed, when refrigeration systems, especially heat exchangers, are dimensioned or selected. This has important impact on the further calculations. As different refrigerants have different properties, it can be assumed that also the optimum process and circuit design differs at some points.
Simple and short comparisons of refrigerants thus usually have to be taken with a pinch of salt. Describing the possible range of comparisons can start with the saying in computer industry "benchmarking is lying" and end with the statement of professor Gustav Lorentzen that, if refrigerants are used in a working range, where they are well applicable, the difference in efficiency is in the range of a few percent. Looking at both, it seems that the way of doing the comparison can determine the result.
Thus, in every comparison, it is important to determine carefully which parameters will be varied and which have to be fixed, to get to a neutral result. In the end, the comparison is meant to help selecting a well suited or the best possible refrigerant for a given application.
For a first selection, the tables below (Refrigerant selection tables) are useful. With some specific know how in refrigeration, the candidates can also be compared using the data in the BITZER RefRuler App, which is easily available.