RADIATOR

A correctly dimensioned heating element is warmest at the top side, near the entrance valve (advance); at this valve the warmed up medium flows into the heating element inside. The temperature decreases downward, since the warmth carried in the carrier medium was transferred over the heating element by radiation and convection to the area. At the lower surface of the heating element a close offable return screw connection is often installed. From there the cooled down medium is led back over the return pipe to the boiler.

 Often erroneously accepted, a heating element must be evenly kept at a moderate temperature from top to bottom. At the latest since the oil crisis in the 1970's the inlet temperature of the heater (and concomitantly the heating element) as a function of the outside temperature is in most cases adapted. Held in some old plants the inlet temperature constantly high, e.g. 90 or 70 °C. This leads to unnecessary calorific losses - above all, if the outside temperatures are no longer so low. , The radiating surface arranged into the area plays a crucial role for the comfort.

The radiation portion of the heat emission of a heating element is however small with small inlet temperatures in relation to convection. Following English term for heating element (radiator) also in Germany heating elements are often called radiators, although the radiation (radiation) is small. The radiated amount of heat rises strongly with the temperature and is higher with electrical radiant heatings or also with steam-claimant heaters. Thus there are attached heat pipes, which possess additional, downward arranged metal sheet metal reflectors in workshops occasionally under the cover, in order to increase the portion of the radiant heat.

In former times above all heating elements from grey cast iron were common; these had - compared to the modern flat heating elements used nowadays - a smaller surface as well as a very high dead weight, were however very corrosion resistant for it. While the time of the national socialism became, in order to withdraw from the armaments industry no ferrous metals, radiators from porcelain offered. These could not become generally accepted however.

In the GDR the idea, and for instance in the middle of the 1950er was again taken up years heating elements from porcelain in 4er or 5er rib blocks were manufactured off. There were in principle two execution variants: flanged and spindled. Here the kind of joining the blocks is meant to the finished heating element. The employment of the porcelain heating elements preferably took place in public buildings such as hospitals, boardings school etc., isolated also in housebuilding. Also mobile electrical radiator heating elements from the porcelain blocks were manufactured by different enterprises. Starting from beginning of the 1960er years the production of porcelain radiators was stopped. 

 

For the up-to-date most usual design the serrated construction is characteristic for the 1960er years from work-hardened and roll-welded steel sheets; thus large surfaces are obtained. In such a way manufactured heating elements are painted or powder-coated. Besides increased also heating elements from steel tube are used; in the sanitary area this design becomes special from practical (towel dryer) and aesthetic reasons preferred. Current heating elements are in different versions (kind of the connections, length, width) and also colors available and after the assembly immediately operational.

 Special forms represent floor and wall heatings as well as cover radiant panels. Here the surfaces of the walls, floors or floor slabs provided with pipes or electrical heating wires serve as wide heating elements.