Designing more sustainable houses with a high energy efficiency is the challenge of the new construction techniques and a priority requirement of the current regulation. Researchers from the University of Oviedo have been developing a pioneering project to prove that the heating and air conditioning systems of the so-called passive houses, whose energy consumption is basically zero, maintain an air quality standard suitable for those who inhabit them. The work will also allow them to improve the integration of bio-construction and housing with a very high energy efficiency.

The group led by Professor Alfonso Lozano is working in a detailed collection of data that shows the concentration levels of CO2 and ionization of the air inside passive houses, which are almost completely hermetic, and whose heating and cooling systems are based on heat exchangers and not conventional energy sources. The first results of the environmental controls conducted prove that the quality of the air inside of this type of houses is truly good and that there are no differences with houses equipped with a normal water heater.

The project Análisis de la calidad del aire interior en viviendas de consumo casi nulo, funded through the University Institute of Technology of Asturias (IUTA), is been developed in conjunction with the enterprises Entreencinas Promociones Inmobiliarias, Intelet Integraciones and Instrumentos Testo. Its research is framed in one of the lines promoted by the Cluster of Energy, the Environment and Climate Change of the Campus of International Excellence.

The data gathered at the Entreencinas house, built in Llanes, allows the researchers to explore new possibilities in the field of modern construction and bio-construction

The work of the researchers will test the suitability of the systems of heat exchangers and air distribution pipes that are currently used in energy-efficient houses. It could also be useful to improve the design of current heating and cooling systems.

Generally speaking, the friction caused by the air passing through the pipes may cause an imbalance of positive and negative ions. Furthermore, the lack of renovation of the air inside the buildings leads to an increase in the levels of CO2. A high concentration of this gas or an excessive ionization of the air may cause diverse symptoms that may damage the health of the inhabitants. The research by the experts from the University of Oviedo proves that the quality of the air in houses whose heating and cooling depend on these heat exchange systems is perfectly normal and adequate.

In order to develop the fieldwork of the project, the researchers have been able to perform measurements in one of the ten Spanish houses that have the status of Passivhaus, the most demanding international certification in terms of highly energy-efficient houses. The Entreencinas house, located in Villanueva de Pría, in Llanes, is a house that is a referent in the field of bio-construction in our country, and which has been recently included in the publication Prefabulous World, Energy-Efficient and Sustainable Homes Around the Globe (Abrams Books, NY) as an example of sustainable bio-construction.

Since the beginning of 2014, the researchers have been taking samples of different parameters to perform a continuous assessment of the standards of air quality of the house. The measurement of the concentration of anions and cations, and the levels of CO2, allowed them to measure the changes brought about by the full use of these heating and cooling systems. The research will facilitate not only testing the air quality of this type of houses, but also exploring the possibilities of integrating bio-construction and the so-called "passive houses".

The registries and results obtained are extremely valuable to tune the design and building of these heat exchange systems. Moreover, the bio-construction techniques, which have been greatly developed during the past few years, have energy efficiency as one of its core design pursuits.

Research Team

• Alfonso Lozano Martínez-Luengas
• Juan José del Coz Díaz
• Alicia Zamora Delgado