Radiation refers to the emission and transmission of energy through space or through a material which serves as a media. Radiation includes electromagnetic, acoustic radiation, particle radiation and all forms of ionizing radiation. Radiation travels from a source in straight lines but may be affected by external factors such as curved paths in magnetic fields.
A radiator manufacturer manufactures devices used to heat an area around it or cool a fluid circulating within it. Steam and hot water heating systems operate by convection where heat is transferred by air currents and not radiation. In radiation, as opposed to convection, heat is transferred by waves that do not need air as a medium for transmission.
Trade radiators are made of cast iron, steel, aluminum or copper. They are contructed in sections to give out efficient heat transfer within a given surface area. Heating efficiency can be affected by screens, shelves, or certain kinds of paint covering them.
If the heating agent is steam, the radiator acts as the condenser and heat is given off at the rate of around .5 calories per gram of steam for each degree centigrade decrease in temperature of 540 calories for each gram of steam that changes to water. Such process is called vaporization. The condensate returns to the boiler where it is reheated to form steam.
Hot water systems made by radiator manufacturers produce a continuous circulatin of hot water. The heat comes from the hot water r steam in the inner wall f the radiator and is transmitted to the outer wall by a process called conduction. It passes by convection currents set up by raising the air temperature that is in contact with the heated surfaces and to a lesser extent by radiation.
Coil radiators made by radiator manufactures consist of long steam pipes and are widely used in factories, gymnasiums, auditoriums and halls and are set on walls or ceilings to maintain floor space.
Gas radiators made by radiator manufacturers use gas flames to heat air or water to generate steam.
Electric radiators consists an electric resistance unit set in a reflector and generates heat when an electric current flows through the unit. A fraction of this heat is transferred from the radiator by means of radiation.