Engine cooling fans

Cooling fans are mechanical devices that removes the hot air and other gases, which is harmful with regards to the safety of the engine unit. These gases and hot air can be discomforting for the people sitting inside the vehicle.

These fans can be categorized in three ways.
1)Fans deliver large amounts of air or gas at low pressure,
2)blowers have high rates of delivery at medium pressure, and
3)compressors deliver at high pressure.

The cooling fan has to be controlled so that it allows the engine to maintain a constant temperature.

Almost all the front-wheel driven cars and vehicles have the electric cooling fans installed in them as their engine is usually mounted transversely. The fans are controlled by a thermostatic switch or by engine computer, and they turn on when the temperature of the coolant goes above a set point. They turn back off when the temperature drops below that point. Usually you find the automatics in more sophisticated cars.

Cars that are rear wheel driven have engines that are usually longitudinally placed and have these engine-driven cooling fans. These fans have a switch that is controlled with the surrounding temperature and is called as a thermostatically controlled viscous clutch. This clutch is positioned at the hub of the fan, in the airflow coming through the radiator. This special viscous clutch is much like the viscous coupling sometimes found in all-wheel drive cars. These types of latest engine cooling fans can be retrieved by placing special orders.

Some designers have applied a semi-analytic and semi empirical formula which is specifically developed for predicting noise radiation from engine cooling fan assemblies. These engine cooling fans significantly reduce the noise that is caused by the engine.