Cordoba-based researchers design a type of façade that could save up to 30% of energy in buildings

Manuel Ruiz de Adana and his work team, from the Department of thermal machines and engines of the University of Cordoba, are involved in the development of a proper air conditioning and good ventilation systems in order to save energy in a healthy environment, as the power consumption in buildings is 40% of the total energy spent in the EU. They are carrying it out thanks to the implementation of passive elements in buildings, such as airflow façades or what they call double-skin façade.

In order to develop this activity, the group is developing a project funded by the R+D+i National Plan of the Spanish Ministry of Science and Innovation, for 2006-2009, which will be presumably extended until 2012. The aim is to obtain clean air at a lower power energy cost, as ‘the air conditioning sector requires a great deal of energy’, Professor Ruiz argued. According to him, the save potential is around 20% or 30% using a double-skin façade system.

One of the solutions to manage to reduce this energy consumption is to provide the building with passive elements, such as airflow façades or double-skin façades. In these architecture elements, the air flows as a result of natural convection in the building’s double-skin façade, and heats free. This way, ‘the façade can be considered as a great solar collector integrated in the actual building’.

Therefore the airflow façade has two skins, that is, two closures. For example, an inside one made of brick and cement, and an outside one, made of stone or sheets. Between the two of them there is an air chamber. In the lower part there is an incoming air grille and in the top part there is an exit air grille that can be positioned towards the building or outwards. When the façade is heated by the sun, the air inside the warms. The warm air flows upwards then and results in a warm air draft. If the building needs heating the warm air gets into the actual building. If no heating is necessary, then the warm air is sent outside.

When the air is sent outside, the heat such warm air has does not get into the building through a conventional closure. That is, in summer the airflow façade insulates the building from the heat.

Therefore, according to Manuel Ruiz de Adana, warm air can be used to increase the temperature of the building in winter. In summer the warm air is ejected outside the building thus obtaining a better thermal insulation and reducing the energy demand. The result is that the annual power consumption is substantially reduced and power saving is encouraged, thus decreasing the environmental impact.







This research group is currently working on air movement problems inside buildings. Once the air has been treated, they want airflows to be used in the areas where people live so as to make the most of the power consumption required for the air treatment. In order to study the different solutions of air spreading in buildings, the control of airflows and the quality if the air obtained, a trial lab has been built in Edificio Da Vinci of the university Campus de Rabanales.

The problem of the air quality is related to the ventilation and air conditioning of buildings. ‘The aim of our last work, which we have been developing in the last three years, consists of analysing the air quality in nursery schools’. This reach group has specifically analysed the air of eight nursery schools of the Basque Country, where ‘we have seen the problems that poor ventilation causes’. As an example, concentration of gases such as CO2 of up to 2,000 ppm. These values ‘are much higher than those allowed by the current law’, he assured.

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