Have you ever wondered why the feeling of hot and cold? Well, it's not just the temperature that determines the Welfare physiological but also humidity: temperature and humidity are in fact perceived together by our body and together determine the so-called hygrometric well-being. The sensation of hot and cold is therefore also linked to the humidity of the air.
What are the ideal temperatures and humidity in a living and working environment? Well, given that this is subjective, it can be said that a temperature around 20 ° C and a relative humidity of the air between 45% and 55% are the reference point of hygrometric well-being and also good energy efficiency. Obviously it also depends on the external conditions: if it is 30 ° C outside, it will be fine even at 25 ° C and it certainly does not help to keep the air conditioner on the contrary.
A thermometer is used to measure the temperature, for humidity there is a hygrometer: these two instruments should be used and read together to keep the level of hygrometric well-being above. When you feel a cold sensation in the house, it may not be enough to raise the temperature of the thermostat, because perhaps the cause is too low a relative humidity. Conversely, the sensation of heat can depend on too high a relative humidity and not only on the temperature.
How to keep temperature and relative humidity under control? Here lies the point: temperature and relative humidity in a building depend on the degree of insulation and the quality of the materials, as well as on the construction technique and a good initial design. Do you want to heat and cool the air with boilers and air conditioners, if the walls do not give us a hand the hygrometric well-being we forget it.
The feeling of thermal well-being that contributes to hygrometric well-being not only depends on the air temperature, but also on the temperatures of the surrounding surfaces: walls, ceilings and floors. In fact, it happens that in front of a cold wall the heat of our body (physiologically stable at an average temperature around 37 ° C) radiates towards the wall leaving us a feeling of cold. If we raise the air temperature, but the wall remains cold, little changes, except that we will spend more on heating.
How to combine energy efficiency and hygrometric well-being? It is true that energy efficiency is important and that a building must consume as little energy as possible for winter heating and summer air conditioning, but this must not take place at the expense of physiological well-being based on hygrometric well-being. Health is at stake.
Waterproof walls can be efficient but they are unhealthy, especially in rooms with high humidity such as the bathroom and kitchen. Waterproof insulation and vapor barriers seal houses in an unhealthy way and only promote condensation. The thermal coats made by applying synthetic insulating panels on the external walls are also dissipative from an energy point of view (they keep out the solar heat) as well as illogical from the point of view of hygrometric well-being, because the building does not breathe.
Good thermal insulation is of primary importance to achieve the hygrometric well-being in a building, as well as for an energy saving speech. Lightweight walls insulated with synthetic materials in the cavities do not work and do not give comfort. Instead, the thick walls of the past work, which have a good thermal inertia and which are built with natural and porous materials, able to breathe and store heat.
The problem is that today there is a tendency to build 'light' and this increases the importance of insulation: rising with the thickness of synthetic insulation does not help hygrometric well-being and makes the environments unhealthy: better to focus on natural and breathable materials that in any case do not give up anything in terms of performance. Natural blond cork, wood fiber, sheep's wool, hemp and jute fibers are among the best performing.
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