A microcomputer program has been developed for simulating refrigerating and air conditioning equipment of all types, air-to-air, air-to-water, water-to-water, and water-to-air. This simulation program is based on a mathematical model of the thermodynamic cycle and on experimental data from equipment testing. Equipment is characterised with a small number of parameters, the values of which are determined from the results of a few testing points. Then the simulation program calculates heating and cooling capacities and electrical power input at any operating condition. It can be used to establish performance listings of the equipment. The simulation program can also be used to investigate the influence of the size of the components (compressor, coils) on performance. Two testing points are necessary to characterise one piece of equipment, and three are necessary when frosting-defrosting cycles occur. For water heat-source equipment, the uncertainty on capacity is about plus or minus 5%. When mass transfer occurs on the air side, the uncertainty is slightly higher plus or minus 10%. The final objective is to introduce the use of such a simulation program in a European certification scheme in order to minimise the required number of testing points for a whole range of equipment.

KEYWORDS: calculating, computer programs, refrigeration, air conditioning, equipment, experiment, microcomputers, air water heat pumps, water water heat pumps, steady state, testing, accuracy, performance, unit air conditioners, refrigerants, thermodynamic cycles, deicing, heat flow