Understanding Auto Cooling and Heating Systems

27 October 2016
 Categories: Automotive, Blog


Many people do not fully appreciate the heat that keeps them warm during the cold winter spell and the cool air that moderates the hot summer temperatures because they have no clue about how auto cooling and heating systems work. If you fall under this category of people, read on to gain some basic understanding of how both systems function to keep car occupants comfortable throughout the year.

The Cooling System

The air conditioning system in your car is responsible for keeping you cool when temperatures are unbearably hot in the car cabin. The system consists of various components but the main ones are the compressor, the condenser, the evaporator, the thermal expansion valve and the drier/accumulator. Here's a look at what each of these five components do:

  1. Compressor: It is responsible for pressurising the refrigerant (coolant) that cools the air. As the refrigerant is being compressed, it rapidly converts into a hot gas.
  2. Condenser: This component further cools the hot compressed refrigerant by drawing heat from it. This turns the refrigerant into liquid form.
  3. Evaporator: It does the exact opposite of the compressor. As the super-cool liquid from the condenser travels through the evaporator, the refrigerant is warmed up back to gaseous state. As the refrigerant passes through expansion valve, it turns back to a low-pressure gas that cools fast inside the evaporator. A cooling fan blows over the evaporator the air before it is eventually distributed via your supply vents.
  4. Thermal expansion valve: It is used to regulate the supply of cool air inside the car.
  5. Drier/accumulator: It is a sort of fail-safe system that absorbs any water that may enter and damage the system.

The Heating System

A car's heating system generally revolves around the functioning of a small component known as a heater core. Very much like a traditional radiator, a heater core supplies heat to the passenger cabin in cold weather. Heated engine coolant is passed through the heater core. A fan is then placed in front of the core so that cold outdoor air can be blown over its fins. As this air passes over the heater core, it gets heated up before being supplied to the car's cabin via the ductwork and heater vents. If you suspect there's an issue with your car's heat, a good starting point for your self-inspection is to place your hand over the heater vents to feel if heated air is supplied.