How Does A Radiator Fan work?
The radiator fan's job is to push air across the radiator and remove heat from the coolant. Engines produce a lot of heat and must be vented to prevent damage. Most engines have coolant that circulates and transfers heat to the radiator. Inside the radiator, the coolant loses heat to the air.
The air that cools the radiator comes from the outside and flows freely through the grill. However, this happens when the vehicle is moving faster than 25 mph. Anything less than this will significantly reduce airflow. This is where the radiator fan comes into play. Helps provide airflow when the car is moving too slowly or the engine is idling.
Radiator fan behavior depends on the type of radiator fan. Electric fans operate differently than mechanical fans. Each task is described separately so that you can understand both operations.
Mechanical Cooling Fan - The mechanical cooling fan is mounted on the crankshaft pulley (usually the water pump pulley). When the car is idling or driving at low speeds, the fan is activated and blows air to the radiator. As the speed increases, the fan either stops spinning or slows down. This is done automatically through the control provided by the clutch. The clutch mechanism works by allowing grease expansion to activate the fan and vice versa, depending on engine temperature.
Electric Cooling Fans - Electric cooling fans have different functions. The switch can be electronically controlled, so no clutch is required. Fans receive power through a complex wiring system of relays, fuses, and cables. For automatic switching, the electric fan uses a temperature switch and a coolant temperature sensor. These sensors send signals to the car's computer to determine when to turn the fan on and off. Modern fans come with their own ECU or control module.
Engine Cooling Fans also work by pushing and pulling air through the radiator. A push-type cooling fan is installed between the radiator and the grill. These are inefficient. A pull cooling fan is placed between the radiator and the engine to provide better cooling performance with more efficiency.
