Refrigeration, air conditioning and heat pump equipments (generally known as heat pumps) are very important for the civilized society. However, discharged refrigerants from heat pumps and exhausted carbon dioxide to drive heat pumps result in serious environmental problems. For this reason, fluorocarbon refrigerants are limited or regulated. To alleviate the problems, new refrigerants with lower GWP and higher cycle performance must be developed and used. In this paper, calculated thermophysical properties of hydrofluoroolefin refrigerants using databases are evaluated with experimental data. Then, the fundamental cycle performance of air conditioning by using major refrigerants is studied based on their thermophysical properties. The results show that there is no adequate refrigerant for air conditioning applications. Heat pumps with new refrigerants including refrigerant mixtures must be developed as fast as possible. It leads to that HFC refrigerants must be used taking care until the new refrigerants will be available.