How an electric boiler heats the air of time.

[Ortograf-fr]

How an electric boiler heats the air of time.



To understand easily and on the simplest example a very general physical law that actually condemns all our traditional heaters, it is enough to compare the operating reports,
- on the one hand for a heat pump operating in good conditions,
- on the other hand for an electric boiler.



A heat pump operating under good conditions commonly has a COP of 4, that is to say it provides 4 joules of heat in return for 1 joule of electricity consumed. (The word COP, or coefficient of performance means efficiency; in other words, a COP of 4 is synonymous with "400% efficiency").

From a boiler Electrical, to get the same amount, ie 4 heat joules, so you consume 3 electric joules more than with a heat pump.

With the electric boiler, you certainly have not sent these 3 joules heat directly in the air, but you did not take the 3 joules out of the open, which obviously you could extract by doing otherwise.

Your electric radiator behaves like a heat pump that would work normally but, at the same time, whenever it consumes 1 joule for its normal operation, consume 3 others to go directly to heat the air time.

In total when the 4 joules in question have crossed the walls of your home to reach their last home, the final balance will be well 1 joule initially electric sent ultimately in the form of heat in the air if you use a heat pump, and 4 initially electric joules sent ultimately as heat in the air if you use an electric boiler.

Electric boiler, yield 100%? Certainly ! Nevertheless, three-quarters of the energy it consumes is used directly to heat the air time!



Additional information:

In a more in-depth physical study, the electric radiator provides a heating with high entropy production, which is, as such, very greedy in energy resources, like all the other traditional heaters.

Heating without producing entropy would be provided by an "ideal" heat pump. It would be extremely low in energy resources, but it only constitutes a benchmark, which is impossible to achieve in practice.

The heat pump is little greedy in electrical energy because it represents a heating with low entropy production.

But the heating by cogeneration is still much better than the heat pump, because the entropy production is much lower. The heat is actually a simple free by-product of electricity production.

However, on the side of the scientific media, all these considerations are systematically censored. As for the pedagogical presentation of the entropy quantity and especially of its concrete meaning, it is absolutely sordid.

Even censorship on the part of the media in general compared to popular articles.

For explanations, see the article entitled: "Cogeneration forgotten at the Grenelle de l'Environnement".


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On this question, a dozen articles can be consulted and uploaded to:
http://alrg.free.fr/ortograf-2008


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