Radiators, as the name suggests, are devices that radiate heat. These heat-exchanging devices can be found in automobiles, buildings and electronics. This device is designed to transfer heat from the water that flows through it, to the air blown through it by the fan.

Often, a radiator is made of a long copper or aluminum tube, bent several times to form a rectangular shape. Numerous small aluminum fins surround the tube. The aluminum draws heat from the warm cooling fluid inside the tube. Once the fins are heated, they release heat into the air, cooling the engine. The radiator has a neck that ends in a cap. The liquid coolant, usually a mixture of water and ethylene glycol, is added through this cap. The cap, known as the