Almacenamiento de energía térmica por calor latente: desde la opacidad a la translucidez.

Comunicación relacionada con la metodología y resultados de la investigaciones numéricas y experimentales relacionados con diversas aplicaciones con almacenamiento de energía térmica por calor latente. Los trabajo presentados incluyen aplicaciones opacas al interior de los recintos y aplicaciones traslúcidas en la envolvente de los edificios

Energy efficiency evaluation of zero energy houses

Given the global energy and environmental situation, the European Union has been issuing directives with increasingly demanding requirements in term of the energy efficiency in buildings. The international competition of sustainable houses, Solar Decathlon Europe (SDE), is aligned with these European objectives. SDE houses are low energy solar buildings that must reach the near to zero energy houses’ goal. In the 2012 edition, in order to emphasize its significance, the Energy Efficiency Contest was added. SDE houses’ interior comfort, functioning and energy performance is monitored. The monitoring data can give an idea about the efficiency of the houses. However, a jury comprised by international experts is responsible for carrying out the houses energy efficiency evaluation. Passive strategies and houses services are analyzed. Additionally, the jury's assessment has been compared with the behavior of the houses during the monitoring period. Comparative studies make emphasis on the energy aspects, houses functioning and their interior comfort. Conclusions include thoughts related with the evaluation process, the results of the comparative studies and suggestions for the next competitions

Performance of passive application of PCM in Spain

Contemporary construction systems tend to be thinner, lighter and better insulated than ever, but usually lack thermal mass. In order to improve the indoor temperature and reduce the energy consumption in the lightweight building it is necessary to add thermal energy storage capacity to the construction elements. Phase change materials (PCM) have high a heat of fusion so they can absorb a lot of thermal energy before melting or solidifying without adding physical mass. The stored energy can be released later when it is necessary. The main purpose of this study is to quantify the effectiveness of PCMs as interior temperature stabilizers in the Spanish construction. Another goal was to identify the influence of the windows sizes and their shading factor in a PCM´s passive application, and find out the most convenient combinations. A comparative study has been made, simulating a Test Room, with and without PCM, to predict the annual interior temperature behavior in each case. The thermal performance of the test rooms was evaluated on an hour to hour basis, in several Spanish climate zones with diverse combinations of facade glazing ratio and window shadow factors (Fs). The results indicate that the addition of PCM to building partitions help to maintain the interior thermal comfort, reducing the high and low temperature peaks in all Spanish climates studied. The PCM thermal stabilizing capacity is more noticeable in summer. However, the Test Room in the warmer climate falls behind in the overall results. The PCM passive application has demonstrated to help to maintain a uniform interior temperature and to save energy, but its use is not a cost effective solution for all the cases in the study. This study helps to identify when, and where, the use of this PCM application should be more appropriate

Methodology in research on photovoltaic cogeneration integrated in building

There are currently various universities and institutions developing research into the integration of photovoltaic systems in buildings, internationally known by its abbreviation in English, BIPV (Building Integrated Photovoltaics). Within this technology, one aspect stands out, considered innovative, the integration of hybrid models or cogeneration. This technology, which we shall call BIPVT (Building Integrated Photovoltaics Thermal), integrates a hybrid module in the building, which not only generates electricity, but also uses residual energy that is lost in the form of heat or light, to increase the energy efficiency of the building, in applications with low temperature. However, the methods to test the efficiency of this investigation and evaluate its cost benefit, are not clear, and constitute a challenge for the investigation within an architectural framework

Passive design strategies and performance of Net Energy Plus Houses

The first step in order to comply with the European Union goals of Near to Zero Energy Buildings is to reduce the energy consumption in buildings. Most of the building consumption is related to the use of active systems to maintain the interior comfort. Passive design strategies contribute to improve the interior comfort conditions, increasing the energy efficiency in buildings and reducing their energy consumption. In this work, an analysis of the passive strategies used in Net Energy Plus Houses has been made. The participating houses of the Solar Decathlon Europe 2012 competition were used as case studies. The passive design strategies of these houses were compared with the annual simulations, and the competition monitored data, especially during the Passive Monitored Period. The analysis included the thermal properties of the building envelope, geometric parameters, ratios and others passive solutions such as Thermal Energy Storage systems, evaporative cooling, night ventilation, solar gains and night sky radiation cooling. The results reflect the impact of passive design strategies on the houses' comfort and efficiency, as well as their influence in helping to achieve the Zero Energy Buildings category

Cerramientos multicapas ligeros en el concurso solar Decathlon 2007

El constante crecimiento de consumo energético en todos los sectores, siendo el caso particular el de las edificaciones que consumen una tercera parte del consumo total. Todo ello surge como consecuencia del crecimiento económico y del aumento de las exigencias de las condiciones de confort, además de utilizar energías fósiles. Si se estudia el consumo energético en las edificaciones, se puede ver que el mayor consumo se genera en climatización con un 46%, luego el agua caliente con 21%, electrodomésticos 16%, cocina 10% e iluminación 7%. Desde la década de los setenta, ha surgido una creciente demanda social por un crecimiento sostenible, originado por una parte por la crisis energética iniciada con el conflicto de Medio Oriente y por otra parte por un cada vez mayor y mejor análisis de la repercusión en el ambiente de nuestras actividades. Esto ha llevado a actuaciones de ámbito mundial como son: El Protocolo de Montreal, AGENDA 21, propone el desarrollo de las energías renovables, disminuir los impactos sobre la salud y el medio ambiente de la producción y consumo de energía y el fomento de una educación hacia el desarrollo sostenible. El Programa 21 de la ONU, plantea el control de aquellas substancias que producen el agotamiento de la capa de ozono. El Protocolo de Kyoto, cuyo objetivo es la disminución de las emisiones de Gases de Efecto Invernadero, en especial del CO2. Dando respuesta a estas actuaciones mundiales la Unión Europea ha desarrollado normativas, tendentes a la mejora de la eficiencia energética y a la seguridad y diversificación de los suministros. Así ha desarrollado: La Directiva 93/76 de 13.09.93 (SAVE), El Libro Verde, La Directiva 2002/91. En España las actuaciones se han presentado con: Código Técnico de la Edificación, Documento Básico “Ahorro de Energía” y Real Decreto 47/2007, por el que se aprueba el procedimiento básico para la certificación de eficiencia energética de edificios. Este certificado deberá incluir información objetiva sobre las características energéticas de los edificios de forma que se pueda valorar y comparar su eficiencia energética, con el fin de favorecer la promoción de edificios de alta eficiencia energética y las inversiones en ahorro de energía. Como respuesta a toda esta serie de normativas para la mejora del consumo energético se tiene, por un lado es el empleo de las energías renovables, como la solar fotovoltaica, solar térmica, eólica, hidráulica, biomasa, geotérmica,… y por otro mejorar el diseño y construcción de los edificios usando cerramientos eficientes, como los multicapa y aún mejor los multicapa ligeros, ya que generan mejores prestaciones en término de confort y ahorro energético

Experiences and methodology in a multidisciplinary energy and architecture competition: Solar Decathlon Europe 2012

Solar Decathlon Europe is an international competition among universities which promotes interdisciplinary learning in engineering and architecture. Students from different disciplines participate in teams guided by several professors during a 29 month preparation period plus five weeks of on-site contest. The educational project involves designing, building and testing a solar energy house connected to the electrical grid with the strategy of maximizing self-consumption, supported by bioclimatic technologies and maintaining a low environmental footprint. It culminates in a on-site contest in which teams must assembly the house themselves, test it with ordinary real life tasks and finally disassembly it. The event has also a divulgative aim, trying to make students and visitors get interested in discovering the problems presented by real engineering and architecture applications. In addition, SDE covers R&D aspects in different fields such as energy efficiency, solar energy and bioclimatic architecture. This article presents the methodology followed during the SDE 2012 edition, in which more than 850 students participated. The obtained results show that the educational competition was a success according to the technical and professional ambitions of the students, most of them considering that their knowledge had increased in areas related to technical and multidisciplinary aspects

Evaluation of three solar and daylighting control systems based on Calumen II, Ecotect and Radiance simulation programs to obtain an energy efficient and healthy interior in the experimental building prototype SDE10

Evaluation of three solar and daylighting control systems based on Calumen II, Ecotect and Radiance simulation programs to obtain an energy efficient and healthy interior in the experimental building prototype SDE1