Abstract: The invention relates to the mixture of natural gases based on hydrocarbons (HC) which do not damage the ozone layer and which have an insignificant greenhouse effect, said gases being substitutes for CFC gases R-12 and R-22, whereby the R-12 substitute is known as HC-12 and the R-22 substitute is known as HC-22. The aforementioned mixtures, which generate a specific pressure/temperature curve, improve the efficiency of air conditioning and refrigeration compression systems. Specifically, since condensation pressures are lower, less pressure and, consequently, less work is required from the compressor, and hence power consumption is reduced. In addition, the refrigerant gases, based on HC mixtures, replace CFCs and HCFCs and are compatible with materials and elements used in commercial refrigeration and air conditioning systems. The resulting mixture generates a specific pressure/temperature curve with a range of plus or minus 5%.