To correctly control the temperature of a vehicle HVAC system.

In a system and a method for detecting and controlling the temperature of a heating/ventilation and air-conditioning (HVAC) system, an infrared ray sensor is used. The infrared ray sensor is used to detect the temperature over several different areas on the surface of an evaporator on which cold spots can be generated. More preferably, the infrared ray sensor continuously scans the entire surface on an air outlet side of the evaporator, and detects cold spots dynamically generated on the surface of the evaporator by using the detected temperature. The system is controlled according to the detected temperature.