is a complex system whose benefits are undeniable and evident: from the unparalleled environmental well-being to the considerable savings in the bill compared to traditional systems for heating the house.
However, precisely because it is a complex system, all the elements that compose it must be optimized to guarantee its efficiency and to allow you to really achieve the savings in the promised bill.
And we are not talking about optimizing only the parts that make up the floor system, but also everything that makes up the environment that the system must heat:
- The building envelope (insulation and fixtures).
- The boiler that will produce the hot water needed for heating (for hydronic type systems).
- The position of the collectors.
- And to finish the whole package that is under the floor.
- This package must be composed of some well-defined layers (or elements), which are regulated at European level, without which the presence of underfloor heating could not even be certifiable.
- In this article we will talk about a particular layer: the insulation needed in floor heating.
As we shall see, the insulation is not a single element but a sub-package made up of various elements and it is fundamental to correctly size it also as a function of the boundary conditions.
Although on our pages we have dealt with this aspect several times, to fully understand the importance of the insulating layer I think it is important to briefly repeat how this heating system works.
The operating principle of a floor heating
When we talk about underfloor heating we are referring to a heating (and also cooling) system that works on a completely different principle than that of the classic radiators or air systems.
The latter heat the room by convection
In other words, only the air near the radiator (or air vent) is actually heated. In this way convective motions are created: the heated air tends to rise and its space is occupied by cold air which in turn will be heated moving upwards, all in a continuous cycle (at least until you turn it off the plant …). It is as if an air current were created inside the room (try to place a handkerchief near a radiator that has been switched on for a while and you will see this effect clearly).
The flaws of such a system are
- Need to bring the water that flows into the radiators at very high temperatures (usually 70 °), with high consumption.
- However, not being able to have a uniformly heated environment (unless you fill the house with radiators).
- In addition to circulating air, it also has dust in circulation not the best for health, especially for allergy sufferers.
A floor heating system instead works with a different principle
In essence, the entire surface of the floor is uniformly heated, so all the air in contact with it warms up, not just a small portion. In this way there is no way to create convective motions but the heat is transferred evenly to the air. Moreover, with careful adjustment, it is possible to establish how far to heat the air: it is in fact useless to heat the whole volume of an internal environment, up to the classic 3m, when the people present will be tall (if they were a family) not more than 2m.