Aircon is simply a cooling system, it simply cools the air. Climate control uses a thermostat (like central heating), so when the temperature rises, on comes the aircon. When the temperature falls too much, on comes the heater. This way it is cheaper to run in terms of petrol used and theoretically more comfortable to passengers. In reality the idiot manufacturers stick the thermostat on the dash where it is heated up by the sun coming through the windscreen, and is about as useful as winding down your window. Anyone want to buy my second hand climate control??