How radiators work

THE radiators (often also called radiators) represent a component of the domestic heating system and allow the transmission of heat in the served environments, through convection and radiation. It is precisely these elements that, in the winter seasons, allow the temperatures of closed spaces to increase. Although nowadays they are in many cases replaced by new devices or different technologies, they still represent one dominant choice in the case of design and construction of new systems. Their performance depends on the materials they are made of, their positioning in the spaces served and their size: let’s see how together in this article.

The operating mechanism

Radiators are not the producers of hot water, but instead represent the way in which the heat of the latter is distributed in the environments they serve. In essence, a process occurs inside the radiator thermodynamic process contrary to what happens inside the boiler:

1. The hot water, coming from the boiler, reaches the generic radiator and heats the material of which it is made. This heat, which is not retained by the material, it is then released to the surrounding environmentmainly through convection and to a lesser extent for irradiation.
2. In the progressive heating mechanism of the radiator, the water circulating in it begins to have a decrease in temperature (it is in fact releasing heat). Once the cycle in the radiator is finished, the water (which has now become cold) moves away and returns to circulation in the systemready to be reheated.
3. The low temperature water, now circulating in the water system, returns inside the boilerto regain an increase in temperature and have sufficient thermal energy to retransmit to the radiator.

The materials

A radiator is mainly made of aluminum (they are the most common), but there are also solutions in steel or cast iron. The spread of aluminum radiators is certainly due to high heating speed of the material. However, rapid heating also corresponds to rapid cooling, which is why steel solutions are usually used, precisely because they perform better from this point of view. This effect is even more important in cast iron radiators (they cool and heat slowly), but they find little use as they are heavier for the same size.

Size and shape

In essence, a radiator is nothing more than a pipe with a shape such as optimize the heat exchange surface in a condensed space. The upper part of the radiator features a sort of nozzlewhich serves precisely to direct the path of the air heated by convection, so as to generate convective motions in the environment and guarantee a better yield in progressive heating. Nonetheless, this continuous movement of air also causes air pollution, as dust is also moved at the same time: for this reason, periodic cleaning of the radiators is always necessary. Ultimately, the size of the radiator depends on the space that needs to be heated and can therefore also vary from room to room depending on needs.

Venting operations

This operation is necessary because, for various reasons, air could accumulate inside the pipe inside the radiator. An accumulation of air causes a reduction in the efficiency of the radiatoras the hot water cannot occupy all the available volume and the heating of the metal occurs in an uneven manner. For this reason, the radiator system is equipped with a vent valve which, if open, allows air to escape from the circuit, restoring optimal operating conditions.

The alternative to underfloor heating

In underfloor heating systems, heat transmission from the system to the environment occurs exclusively by radiation. In essence, pipes arranged beneath the flooring, in which the high-temperature fluid circulates, they transmit heat to the environment in a practically homogeneous manner. In this case, therefore, specific elements such as radiators are not necessary, as everything already happens inside the system positioned on the ground. This type of solution, among other things, does not generate the movement of dust due to convective motions.