<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (February 2017) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (February 2017) (Learn how and when to remove this template message) </Td> </Tr> <P> Radiators and convectors are heat exchangers designed to transfer thermal energy from one medium to another for the purpose of space heating . </P> <P> Denison Olmsted of New Haven, Connecticut, appears to have been the earliest person to use the term' radiator' to mean a heating appliance in an 1834 patent for a stove with a heat exchanger which then radiated heat . In the patent he wrote that his invention was a peculiar kind of apparatus, which I call a radiator . The heating radiator was invented by Franz San Galli in 1899, a Prussian - born Russian businessman living in St. Petersburg . In the late 1800s, companies, such as the American Radiator Company, promoted cast iron radiators over previous fabricated steel designs in order to lower costs and expand the market . </P>

Where does heat come out of a radiator