Unfair information and wrong political choices shaped a cultural attitude against the use of electricity as a source of heating.
In nearby countries and particularly in northern ones electrical heating is becoming the most used system.
It's easy to understand why:
- Lower running costs
- Lower installation cost
- Less pollution
- More safety
- More flexibility
Now even here, thanks to the obligation of greenhouse gas cutting according to Kyoto protocol, to incentives, to fiscal allowances, to the liberalisation of electric power providers, using electricity to heat our houses is getting cheaper and cheaper.
In order to understand why electrical radiant panels are more convenient, it's necessary to outline some points which are not so well known:
(A) The traditional heating systems based on water, with a boiler and radiators in a floor or on walls use the combustion of natural gas, gas oil and wood to produce thermal energy. The efficiency of boilers - sometimes up to 90/95% - declared by makers refers to particular conditions of continuous working and to a definite power. But in reality the working of a boiler is intermittent and at different powers, so that its efficiency can be as low as 50%. Just to make an example we could think of the stated fuel consumption of cars which is never real: in fact in practice it will be lower because the theoretical one is measured according to certain abstract and general criteria valid in all circumstances, but not keeping into account the real driving on a road. Maybe these criteria could be useful to compare two car models. The boiler heat is forwarded to the water, which is in turn pushed into the pipes by recirculating systems to finally reach the radiators. So, it is natural that along all these steps there is more energy wasting affecting the final efficiency of the whole heating system. At the end of the day, the idea of heating water in order to heat an environment is little efficient from the point of view of its final results.
(B) The hot water reaches the radiator, the one that has got to heat the environment. The radiator will yield its heat to the surrounding air - it is in fact built purportedly to maximize this thermal echange - and the warm air will then in turn heat the environment. This is convection heating. This concept of heating is not functional for different reasons:
- Hot air always tends to rise, so that air motions occur and these will carry dusts which inevitably are breathed.
- As hot air tends to rise, there will be a stratification of different temperatures in the same environment. To reach 20° C at a height of 1,5 / 2 m. - which is the usual standard - the air layer closer to the ceiling may reach 25° C, and at floor level it may be 16° C. It's evident that at such conditions there can't be much comfort: your feet will be cold and the breathed air will be too warm and dusty. Furthermore, the hot air at the top levels is quite useless and it just means a waste of energy.
- In an environment heated by convection it is the hot air that little by little yields warmth to the walls, but in a very limited form as the warmth is forwarded to the walls by conduction (that is, the air yields its warmth when it touches the walls) and this means that the walls are always colder than the circulating air. This is why in places heated by convective systems one generally feels an impression of cold even if the air temperature is 20° C. Our body, warmer than the walls, yields warmth to the walls through radiation, and so we feel cold.
- To avoid this shortcoming, people tend to increase the air temperature of 2°/3°C. This, as well as increasing the convection motions with consequent more discomfort and more dust, increases enormously power consumption. In fact much more power is needed to increase the temperature from 20° to 22° than from 16° to 18°, as the difference between outside and inside temperature increases and consequently the loss of heat increases too.
- More loss of heat occurs when the heating factor, that is hot air, escapes from a given environment taking away the heat passing through opening doors and different droughts.
Compared to the above, RADIEL radiating system proves better under any point of view:
- The efficiency is 100% all the time as the absorbed electric power is wholly transformed into radiating power and directly forwarded to the environment.
- Heat is spread through radiation. The 2cm stone with its flashing stops the weak convection motions always occurring when a surface is warmer than the surrounding environment and at the same time they increase its radiating surface - a rough surface is better than a smooth one of the same size -. Radiation, a propagation of infrared rays, also called thermal rays, has got the characteristic of heating solid bodies - walls, floors, human bodies, etc. - without heating the air, as it is an electromagnetic wave. There is no moving dust, the breathed air feels fresher and one has the pleasant perception of healthy penetrating warmth. The inside temperatures of a room appear homogeneous in every point: in fact the temperature difference between the floor and the ceiling may be 1°C. As there is no need to heat the air, but only the walls and the body, there is no waste and no further loss of heat from the escape of hot air, which now is no more the heat-carrying factor. All this means high power and money savings.
- In a radiation-heated environment, the walls and the whole environment feel warm and the air feels fresher; this doesn't allow at all the formation of mildew on the walls, even if the air is particularly humid (kitchen, shower). Mildew in fact comes out on wet walls: this wetness occurs because of the condensation of the humidity in the hot air when it gets in touch with the cold walls.
- Warm and dry walls loose less heat, are thermally more isolated, and this means power saving. This is another factor determining less need of w/square metre to heat an environment with pure radiation systems.
- Last but not least, radiation is good for the human body. Radiant heat in fact penetrates the body in a deeper way than the heat from the air. Studies in naturopathy have compared this type of heat to heliotherapy with reference to the advantages it may give to one's health. This is even more evident if radiant heat comes from natural surfaces such as stone. This doesn't charge electrostatically and has a reductive effect on the convective motions of the air, and, when the stone heats up, its molecules vibrate with a particular frequency we perceive as different and more pleasant. Furthermore flashed stone surfaces, even if very hot, don't burn the skin if they are inadvertently touched. This is very important for families having naturally curious children who tend to touch everything.
From the considerations made above at the points (A) and (B) we can deduct that conventional heating systems show a very low efficiency that may be quantified as follows:
- About 30% of the power produced by combustion goes lost during the several steps of the system (never perfectly working boiler, energy consumption of electrical circulators, pipe losses even when they are perfectly isolated, thermal bridges, etc.)
- A further 40% is lost because of the wrong idea of heating by convection instead of heating by radiation.
In conclusion, it is evident that a conventional heating system is little efficient from the point of view of perceived comfort with reference both to energy and to the environment.