Air conditioning systems are of great importance in contemporary society, and it is therefore necessary to evaluate their environmental impact and the way in which they relate to the sustainability of our planet. The present work aims to evaluate the process of replacing R-22 refrigerant in air conditioning systems by alternative refrigerants with low GWP values due to the large number of systems that still use it, especially in developing countries, such as Brazil. To allow an effective comparison between the refrigerants, a methodology was developed to measure, the cooling capacity, the coefficient of performance and heat transfer rates of air conditioning systems using the fluids R-22, R-444B and R-454C. The results show average reductions between 8.8% and 17.6% in the cooling capacity and between 6.8% and 8.8% in the coefficient of performance. Considering the ecological aspect, with the use of refrigerants that do not harm the ozone layer and with a low impact on the greenhouse effect, the present study demonstrates the viability of the retrofit of the R-22.