Radiators

Radiators are heat emitters used in buildings as part of centralized or electric heating systems. They transfer heat to occupied spaces primarily by convection and radiation. Radiators can be powered by hot water or steam from a boiler, or by electric resistance heating.

In hydronic systems, water is heated in a boiler and circulated through radiators by a pump. Steam radiators use steam pressure in pipes to heat radiators and emit heat as the steam condenses. Electric radiators use electric resistance coils. Common designs include cast-iron or steel panel radiators, column radiators, and towel radiators, each with varying heat response and aesthetics.

Operation involves the boiler heating the fluid and valves regulating flow to individual radiators. Warm air rises from the radiator and mixes with cooler room air, while the hot surface provides radiant heat to nearby objects and people. Thermostats or thermostatic radiator valves can maintain target temperatures and improve efficiency. Periodic maintenance may include bleeding to remove trapped air and checking for leaks.

Materials differ in heat properties and response. Cast iron radiators store heat longer and release it gradually, while steel and aluminum radiators heat up and cool faster, allowing quicker temperature adjustments. Many systems use low-temperature radiators designed to operate efficiently with modern, condensing boilers or heat pumps.

History notes that radiators developed in the 19th century, with notable contributions from inventors such as Franz San Galli. Today, radiators range from traditional cast-iron units to compact panel designs and electric models, serving varied heating needs in homes and buildings.