The incredible staying power of the cast iron radiator is born of more than just smart design and a yen for the traditional architectural styles of the early 20th century – cast iron radiators are widely celebrated, by house builders and home owners alike, as one of the most efficient ways to heat a building. These radiators are made from a particularly dense iron which is perfect for conducting and storing heat, making their heat output far superior to comparable forms of central heating.
Cast iron radiators remain one of the most comfortable, quiet and reliable ways to heat a room. The radiators are slow to heat up and cool down, making the heat produced very even and gradual. The iron retains heat long after the radiators have been turned off, keeping rooms cosy even when the heating is not switched on.
In technical terms, there are three factors which determine the heat output of cast iron radiators – the ambient temperature of the room, the temperature of the radiator itself and the surface area of the radiator. When determining a radiator’s average heat output the general air temperature is usually assumed to be 70 degrees centigrade, while the temperature of the radiator is dependent on the temperature inside its pipes. There are two kinds of hydronic heating systems which utilize cast iron radiators – hot water systems and steam systems, both deriving their heat from boilers. These systems are capable of generating extreme heat.
The surface area factor is important insofar as the larger the radiator, the more heat it is capable of radiating. This is measured in terms of Square feet of “Equivalent Direct Radiation” (EDR). When a heating engineer calculates what is necessary to heat an entire building, they will multiply the total square feet EDR ratings of all its radiators by either 170 BTUs (British thermal units) per hour with a hot water boiler or 240 BTUs per hour for a steam boiler.
Different models of cast iron radiators have different BTUs, depending on their size, shape and style of construction. While a reputable radiator supplier is the best person with whom to discuss which models are best for your home, it is safe to say that comparing size with size, cast iron radiators will almost always provide a greater level of heat output for your money – and will continue to do so reliably for many years to come.