What is bioclimatic architecture?

Bioclimatic Architecture is a kind of architecture adapted to the Environment whose design envisages reducing energy dependence through the exploitation of the energy possibilities offered by the surrounding climate.

A bioclimatic building is the one that adapts to its environment and makes the most of it, the solar radiation, the air currents, etc. In this way the people living in it are provided with the same comfort but with an energy consumption level well under the usual ones.

The reduction of the energy consumption in buildings not only represents lower economic costs for its user, it also entails a decrease in the pollution associated to production and reduces the dependence on limited fuels.

One of the first factors that will help us reduce energy waste is its conservation. If we manage to keep energy, we will reduce its need for it. There are various ways of maintaining energy in buildings.

  • Thermal insulatorsin building enclosures reduce the heat lost through them by a quarter.At present there are different specific materials for every situation, to inject in chambers, to insulate the indoor areas from the outside, etc.; therefore, all the building units should be insulated. An appropriate kind of insulation will preventthermal bridges or thermal leaks, which are to blame for 20 percent of the energy lost in buildings.To avoid this, it is advisable not to reduce the width of the enclosure and use compact splayed arches and joinery. It is advisable to combine the use of insulators with a steam layer to avoid condensations in the inside layers of the enclosure.  
  • Technically, the weakest points in buildings are the glazed hollows, hence the importance of the right choice of the joinery and the glass. The use of double glazing orinsulating glassremarkably reduces energy leaks as well as being an excellent acoustic insulator. On the other hand, the air tightness of the joinery will stop the leaks. As regards the glazed hollows with a continuous exposure to solar radiation, a solution could be the use of low-emissivity glass or reflective or tinted glass panes.

The second feature is the free collection of energy from the Environment, which involves the use ofRenewable Energiesin general, even if there are specific strategies to achieve heating or cooling in a natural way.

Passive strategies to collect heat

Basically, these strategies consist in exploiting solar radiation in winter to heat the inside of buildings. The main one is the suitable orientation of glazed hollows, bearing in mind the necessary protection to avoid the counterpart in summer.

The best orientation is southwards since the hollow receives the highest radiation. The right sizing of the hollows will enable the winter sun to penetrate deeper in the rooms as the sun is in a lower position, whereas in summer, as it stands higher, it will reduce its angle of incidence and its penetration will be lesser.

Passive cooling strategies

The main strategy consists in avoiding and getting rid of overheating, essentially with ventilation.There are mechanisms to force ventilation in a natural way such solar chimneys. The tendency for hot air is to go up, as it is lighter than cold air. If a top opening is made (chimney) on an inside point, preferably on the south façade where heat concentrates the most, and a bottom opening such as a window on the north face, a movement of air will take place cooling the house.

Another cooling strategy is the one used in the well-know Andalusian courtyards or in the Alhambra in Granada. These courtyards pocket the air cooled over the night and exchange heat in daytime with the surrounding rooms. Until the air is not heated, it does not flow through the courtyard by convection, and cools down again at night. This system is supplemented with the installation of fountains or water stretches that get evaporated, providing a cool atmosphere.

The system of the ventilated façade enables a better thermal performance indoors. It consists in the creation of an intermediate ventilated chamber between the enclosure blades of a building, so that cold air penetrates through the bottom part, warms up as it absorbs the heat produced by solar radiation, and leaves through the top part.

The system of green roofs or pocketed water on the roof enables the daytime absorption of the building indoor heat, which dissipates over the night.