Heating and air conditioning Issues Explained: A Complete Breakdown

How it Works: Heating and air conditioning

The heating and air conditioning system in a vehicle maintains cabin comfort by regulating temperature and airflow. It operates through a coordinated network of mechanical components and sensors designed to manage heating, cooling, ventilation, and humidity control. When heat is required, the system draws heat energy from the engine’s coolant. As the engine runs, it heats the coolant circulating through passages. Hot coolant flows into the heater core—similar to a compact radiator—mounted inside the dashboard. Cabin air passes over the heater core, absorbing warmth before entering the interior through vents controlled by adjustable flaps and blower motors. For cooling, the air conditioning system circulates refrigerant in a closed loop comprising a compressor, condenser, expansion valve, and evaporator. The compressor pressurizes gaseous refrigerant, pushing it into the condenser located at the front of the vehicle, where heat dissipates, condensing it into liquid form. This liquid refrigerant then passes through an expansion valve into the evaporator inside the cabin, where it rapidly expands and cools dramatically. Warm cabin air is blown across the evaporator, transferring heat from the air to the refrigerant. The cooled air is then distributed throughout the cabin via air ducts. Sophisticated climate-control systems utilize sensors to continuously monitor cabin temperature, adjusting airflow, refrigerant flow, and heater operation automatically to maintain the selected comfort settings, ensuring optimal performance across varying environmental conditions and vehicle technologies.