Convector heaters

A convector is called a housingd heat exchanger that gives off the majority of heat by convection. This exchanger is most often copper tubes, on which the so-called. Slats, i.e. properly shaped ribs, for example. Aluminium. Therefore, these are heating elements in the form of steel or copper ribbed wires placed in a sheet metal casing and differently built in rooms. The simplest example of a convector heater, illustrating the principle of its operation, shown in the figure.

An example of the construction and principle of operation of a simple convector. Marks: H – mounting height; g – mounting depth; h1 – the height of the air supply opening; h2 – height of the inlet opening.

Cool air flows through the air inlet from below (with the height h2), and then after heating on the surfaces of the convection elements into the room. The heating capacity is regulated both from the supply side (valves on the heating water pipes), and from the air side (through the use of valves and regulating flaps). Convectors are installed not only at the external partitions, but also at interior walls, as freestanding, and sometimes even in a floor niche.

Illustration of selected options for installing convectors. Marks: 1 – under the window sill (traditional way), 2 – against the wall, 3 – free standing, 4 – built into the wall recess, 5 -built below the floor level (with air intake from the room)

The figure shows the ways of their assembly. Due to the need to ventilate rooms, the solution is often used, consisting in supplying external air with the help of fans (forced convection). Such a solution is shown schematically in the figure.

Convector example. Marks: 1 – convector (heating cable), 2 – outdoor air, 3 – indoor air (secondary), 4 – distribution chamber, 5 – nozzles

Outside air (after cleaning on the filter and pre-heating or cooling in the air handling unit) is fed into the room through a nozzle and sucks in air from the room. Such structures can also work with the use of only internal air.

Thermal efficiency of selected types of convectors supplied from the air handling unit

The table presents the heat output of convectors of various heights and installation depths, assuming the supply of heating water with parameters of 90/70 ° C and at a heated room temperature of + 20 ° C. If other parameters of the heating water are used, sets of coefficients correcting their thermal efficiency are developed.