House and moon

House and moon

It is common knowledge that the moon goes through phases depending on its relative position between the earth and the sun. Thanks to that nights can be a showcase for looking to the starry skies or the perfect environment so that lycanthropes can take on vampires.

In science there are also phases, and the phase shifting, relative to the state in which matter is found. However, changes in this case have to do with temperature and heat and not with the states of the moon.

State transitions, have an important advantage and is that they are produced at constant temperature, allowing the matter to acquire and give up heat without changing temperature and thus reducing the impact over the environment that surrounds them. Are changes that, unlike the transformation suffered by David Naughton in “American Men in London” (film that achieve an Oscar in 1981 to the best makeup), aren´ t visible, but they are perceived.

The application of phase change materials, in particular those that have inside the homes usual transition temperatures between 18ºC-25ºC, can be used as recoveries in walls with which can reach a bigger comfort by stabilising the inside radiant temperature. It´ s not rare to found homes that because of a bad insulation are like thermic vampires, they remove us the heat, increasing the energy bill.

Inside the SUDO-SUDOKET project, which objective is the development of Key Enabling Technologies (KET) applied to innovative buildings, phase change materials dissolved in mortars have been studied to check its effect over the inside comfort conditions, as well as the effect over the climatization consume.

The results of the project had led to conclusions such as that a better stabilization of inside temperatures are reached if the radiant temperature is improved and, moreover, a reduction in the consume of climatization equipment, reaching energy saving, working as if it were a ring of garlic tied around the neck of our air-conditioning system.

The same as our favourite satellite goes from new to full, the enclosures of our homes will evolve to a future with a better control in superficial temperature and evenmore with adaptative enclosures that change of phase depending on the outside conditions.


The work has been done inside SUDOKET – mapping, consolidation and dissemination of Key Enabling Technologies (KETs) project for the construction sector at the SUDOE space, ref: SOE2/P1/E0677 that is co-financed by the Europeand Found of Regional Development (FEDER) through the INTERREG SUDOE programme.

Solar cooling & Tao. The sustainable cold way

Solar cooling & Tao. The sustainable cold way

The Taoist philosophy defines through the Ying and Yang duality, that has everything that exists in the universe, so that there are always two antagonistic and complementary forces that need each other. You can hardly appreciate the value of the Peace without the existence of wars or health if there were no diseases.

This dual approach is also applicable to technology, imposing conditions that often are opposite, but allow the balance of systems. According to the Thermodynamics, for the production of cold (heat extraction to a source of lower temperature) has to provide external power and dissipate heat to a medium that is hotter than the area you want to cool, so that the heat and cold coexist like the Ying and Yang were addressed.

The conditions of habitability that living beings we have, they require us to maintain a suitable temperature to carry out life processes, in such a way that values at 23 ° C environment, they allow us to be comfortable. However the weather and outdoor conditions present values sometimes far removed from this optimum: from – 40 ° C, which can be in areas close to the Poles, up to 55 ° C which can be summer in areas close to the Equator being essentially the presence or absence of solar radiation which causes these differences.

Technology has developed systems for the transformation of solar energy into heat or electricity, making it applicable to both heating and cooling. The absence of solar radiation produces the need for heating, and therefore it seems unlikely that we can take advantage of the available radiation that will generally be small for heating. However, the need to cold will be generally associated with the presence of sunlight, as if they were also of the Ying and Yang. In fact the air conditioning is one of them technologies star for the World Football Championship of Qatar in which is going to use fields of soccer refrigerated through energy solar (“Wolfgang Kessling: “How to air-condition outdoor spaces”).

The solar cooling offers a set of technologies in which the solar radiation is used to produce cold water with sorbents systems (absorption or adsorption machines) previously heated with solar panels or from electricity produced with photovoltaic solar energy to power a system based on compressor. As if they were the brothers of “Rich man, poor man”, their temporal evolution has been and is different.

Until makes some 10 years, were the systems of cold solar based in machines sorbent which had of a greater number of applications and developments technological. In those days the photovoltaic face was expensive. However, with the reduction of the cost that has suffered recently this last, the use of photovoltaic to produce cold solar is increasing of way important. On the other hand, there are manufacturers of machines of absorption with systems of triple effect and yields of the 180% willing to present a hard battle for the air conditioning with radiation solar.

In any case regardless of the technology that is winner, I have clear is that, the future of the cold is hot, as hot as the Sun.