Radiators are types of converter which exchangers heat designed to
transfer thermal energy from one medium to another for the purpose of
cooling and heating. The majority of radiators are constructed to
function in automobiles, buildings, and electronics.
One might expect the term 'radiator' to apply to
car parts which
transfer heat primarily by thermal radiation, while a device which
relied primarily on natural or forced convection would be called a
"convector". In practice, the term "radiator" refers to any of a number
of devices in which a liquid circulates through exposed pipes,
notwithstanding that such devices tend to transfer heat mainly by
convection and might logically be called convectors. The term
"convector" refers to a class of devices in which the source of heat is
not directly exposed.
In all automobiles with a liquid-cooled internal combustion engine a
radiator is connected to channels running through the engine and
cylinder head, through which a liquid (coolant) is pumped and many car
The radiator transfers the heat from the fluid inside to the air
outside, thereby cooling the engine. Radiators are generally mounted in
a position where they will receive airflow from the forward movement of
Where engines are rear- or mid-mounted, it's usually still
necessary to mount the radiator behind the front grill, so as to achieve
sufficient airflow, even though this requires long coolant pipes.
Automobile radiator is constructed of a pair of header tanks, linked by
a core with many narrow passageways, thus a high surface area relative
to its volume. This core is usually made of stacked layers of metal
sheet, pressed to form channels and soldered or brazed together. Many
years radiators were made from brass or copper cores soldered to brass
headers. Modern radiators save money and weight by using plastic headers
and may use aluminum cores. This construction is less easily repaired
than traditional materials.