The professionally designed top mounted parking air conditioning system has excellent environmental adaptability. The host casing is made of engineering materials that are resistant to ultraviolet radiation and corrosion. The internal electrical components are treated with shock and moisture resistance, and can withstand temperature differences from extreme cold to heat, as well as erosion from harsh weather conditions such as rain, snow, wind, sand, and salt spray. Its working voltage range is wide and can adapt to common voltage fluctuations in vehicle circuits. In addition, as a professional equipment, the design life of its core components (such as compressors) far exceeds that of ordinary vehicle electrical appliances, and has been strengthened for vehicle vibration environments.