The car air conditioner ”ac” works on the similar phenomena as the normal domestic ac. The compressor pressurize the refrigerant and sends it to the condenser which condenses the refrigerant by cooling it using the condenser fan, the throttle valve of the ac releases the pressure and temperature of the refrigerant and finally goes to evaporator coil which are fitted inside the dashboard the blower blows the air in the cabin and refrigerant evaporates in the evaporator which causes cooling. Again the refrigerant in gaseous form goes to compressor and the cycle goes on.
Difference is that the Compressor of domestic ac is driven using the electricity and the car compressor is driven using the power from the crankshaft using belt drive.
When the heater is switched on the hot coolant from the engine flows through the evaporator coil thus providing heating effect in the cabin. Refrigerant is prevented from flowing in the evaporator using valves.
Does a car’s AC consume more fuel if you put its control on High level?
There is two parts to your cars air conditioning system.
- There is the compressor which compresses the refrigerant and when it expands it removes heat from the evaporator coils. This is usually controlled with a clutch and driven off the engine directly.
- Then there’s the circulating fan which blows air past the evaporator coils to chill the air. This is usually driven by the car’s electrical system.
So the compressor only has one speed. The circulating fan usually has three speeds low, medium, and high. The compressor uses the bulk of the engine power that goes to the air conditioning system. The blower fan uses a smaller part. However high does use more electrical power than low or medium, so there is a small but not great effect on the car’s gasoline consumption by using high.