Radiators and convectors are types of heat exchangers designed to transfer thermal energy from one medium to another for the purpose of cooling and heating. Majority of the radiators are constructed to function in automobiles, buildings, and electronics.

 

The fluid is pumped in a closed system from the radiator to the engine, where it absorbs and conducts heat away from the engine parts and carries the heat, primarily, to the radiator.

 

The radiator is, on many conventional vehicles, typically mounted behind the vehicle's grille, with outside air driven through the radiator by the vehicle's forward motion. There are other mounting options for the radiator, especially in mid- and rear-engine vehicles, and some vehicles have characteristic body ducts and vents to ensure that air is conducted through the radiator core. Movement of the air through the radiator usually needs to be supplemented by a fan so that the engine can be cooled while stationary or working hard. However the fan will absorb excessive power at speed, so variable pitch, or friction drive, mechanical fans and electric fans are normally used on faster vehicles such as cars.

 

Some vehicles, such as liquid-cooled motorcycles, do not have any supplementary feature for inducing airflow through the radiator. The radiator transfers the heat from the fluid inside to the air outside, thereby cooling the engine.