In this work, a compression type HVAC (heating, ventilating, and air conditioning) system has been studied. The aim of the work was improving the cooling operation and performance of the system, elimination of the freezing problem of the compressor, increasing the efficiency, decreasing the energy consumption and reducing the working duration of the compressor. The results of numerical solution of the computational fluid dynamics has been crosschecked with and interpreted according to the experimental data. The results of the exploited modifications based on the numerical solution have been presented in the form of contours and velocity-temperature plots. Eventually, troubleshooting of the HVAC system resulted in the elimination of the compressor freezing accompanied with convenient air conditioning and ventilation. The temperature and flow of the provided air, decreased 7 oC and increased by %13, respectively.