The air conditioning system for a bus should be selected considering a number of parameters, including passenger capacity, local climatic conditions, and fuel consumption. It is possible to determine whether a selected air conditioning system provides desired performance through testing. This study examines how to verify experimentally whether a bus air conditioning system meets design and comfort requirements. An experimental study was conducted on a prototype bus and was tested when driving on the Adana-Ceyhan highway in Turkey. The internal and external temperatures, evaporator inlet and outlet temperatures and relative humidity values were measured. Thermal sensation values were calculated by using empirical correlations given
by ASHRAE. Furthermore, the instantaneous cooling load of the bus was obtained according to the experimental
data, and the results are compared with the calculated cooling load of the bus by using the radiant time series method provided by ASHRAE. With respect to the obtained results, the selected air conditioning system conformed to design and comfort requirements.