Sectional radiators

The largest group of solutions used in central heating installations are sectional radiators. They consist of identical members (also called cells) creating the desired heating surfaces. They belong to the group of convection type heaters, Ie. Heaters, for which the share of heat emitted by convection accounts for more than half of the total emissions. However, the ratio of heat dissipated by convection and radiation varies depending on the design of the members.. Members can be made of cast iron, Steel, aluminium, and even of ceramics or plastics. Ceramic heaters are fragile and expensive and have not been widely used so far. Similar considerations apply to aluminum radiators. The low use of aluminum radiators is due to high prices, and also with a high risk of corrosion, when the chemical composition of the heating water is unfavorable.

An example of aluminum member heaters is shown in the figure. The technical data are summarized in the table.

Technical parameters of a single element of an aluminum radiator (typu Silumin)

These heaters have four air inlets in the form of guides, ensuring the outflow of heated air towards the room.

The most commonly used are cast iron heaters, steel or other metals. Cast iron radiators, thanks to their high resistance to corrosion, can be used even in excess of 100 years. This is their unquestionable advantage compared to steel radiators. Moreover, they are resistant to mechanical damage and pressure changes. However, they have a large water capacity, hence high thermal inertia. Their heavy weight causes, that they are also replaced by sectional steel heaters, which are cheaper and offer the possibility of removing failures by welding. The individual elements of cast iron radiators are connected by means of the so-called. union (with right and left threads), and gaskets of plastic or other newer materials are used for sealing. In order to stiffen them, a stabilizing wire is inserted inside, called a cheat sheet. Due to the requirements of thermal comfort and air circulation in heated rooms, heaters are usually placed under the windows.

Dimensions and installation conditions for section heaters. Marks: a- 40 Mm (cast iron radiators) or 50 Mm (steel), b – 31 Mm (cast iron radiators) or 20 Mm (steel), c – 60 Mm (cast iron radiators) or 50 Mm (steel), d – minimum 65 Mm, e – minimum 70 Mm, f- minimum 40 Mm, g – building depth, H – building height, h – distance between nozzles axes, 1 – insulation board (so-called. radiator screen – for example. insulation material covered with aluminum foil)