Effects of the type of facade on the energy performance of office buildings representative of the city of Barcelona

The aim of this article is to analyze the energy efficiency issues of eight office buildings built in Barcelona. Using computer simulations to compare energy demand and level of indoor natural lighting, it is demonstrated that there are considerable differences in demand – in some cases more than double – depending on the type of facade, and these differences are not directly related to the economic cost of the construction solutions used. In all cases, the cooling demand represents more than 80% of the total climate control demand, and solar radiation is the parameter with the greatest effect. The overall solar factor of the facade stands out as a key variable to control to both reduce the overall energy needs of a building and separate the cooling demand from the orientation of the building. The level of natural lighting is a differentiating element only in cases that had similar thermal energy performance.Peer ReviewedPostprint (author's final draft

Gestió de l’aigua en el creixement de les ciutats

En el marc de l’assignatura d’Urbanisme i Serveis Urbans, en els darrers anys, fem especial incidència en la gestió de l’aigua en la urbanització de la ciutat tant en les zones habitades com en els polígons industrials.Peer Reviewe

Investigació i recerca en sostenibilitat i eficiència energètica dels edificis

L’elevat consum d’energia dels edificis representa un problema que no és possible d’assumir a llarg termini sense considerar mesures d’estalvi i eficiència energètica com a eines bàsiques cap al desenvolupament sostenible. És per aquest motiu que des del Departament d’Enginyeria de la Construcció considerem com una qüestió cabdal la participació en aquesta problemàtica de l’alumnat de les assignatures que impartim, especialment en el cas de l’assignatura de Construccions Industrials.Peer Reviewe

Thermal performance of ventilated double skin façades with Venetian blinds

Peer ReviewedPostprint (published version

Empowerment in the community. The design of an open indicators system from Participatory Evaluation processes.

[ES] Existen numerosas perspectivas y aproximaciones conceptuales a la Evaluación Participativa (EP) y a los significados y sentidos que esta puede tener. En todos los casos, supone un cambio de perspectiva en los modelos de evaluación, planteándose como un proceso de aprendizaje individual y colectivo. En las siguientes líneas se pretende avanzar en averiguar de quémanera los aprendizajes generados en procesos de EP contribuyen al empoderamiento de las personas y comunidades que protagonizan dicha evaluación. La aportación que aquí se presenta describe el diseño y ensayo de un sistema abierto de indicadores de empoderamiento que pretende evidenciar el aprendizaje que procesos como la EP generan en las personas que los viven. A través del análisis de la literatura y la discusión con investigadores, técnicos y agentes comunitarios, se detectan variables e indicadores de empoderamiento. Estos indicadores se ensayan en tres estudios de caso que nos permiten comprobar su utilidad. Para ello se aplican cuestionarios, el análisis de contenido de las actas y transcripciones de las sesiones de EP y la realización de entrevistas semiestructuradas a los miembros de los grupos de EP. Se presenta el listado general de variables e indicadores de empoderamiento, entendido como un sistema abierto, como una matriz generadora, en la medida que puede completarse y contrastarse a partir de las nuevas aportaciones que surjan con su aplicación. A partir de la contrastación bibliográfica, se han validado la mayoría de indicadores propuestos. El sistema además propone indicadores poco habituales en las formulaciones realizadas hasta ahora, pero que en esta propuesta han sido validados a través de los estudios de caso. Se considera el material presentado como un buen punto de partida para posteriores investigaciones y una ayuda para reforzar enormemente el discurso y el valor de las acciones socioeducativas y el trabajo comunitario. [EN] There are several perspectives and conceptual approaches to Participatory Evaluation (PE) and the meanings and senses that it may have. In all cases, it involves a new point of view among assessment models, as it is considered itself as a process of individual and collective learning. In this article we aim to deepen in this topic; and to find out how this learning contributes to the empowerment of individuals and communities who are lead this evaluation. This paper describes the design and testing of an open indicators system to highlight empowerment, which aims to show the learning that EP processes generate in the peoplewho experience it. Variables and indicators of empowerment are identified through literature analysis and discussion with researchers, technicians and community workers... These indicators are tested on three case studies, which allow verifying its utility. In these case studies we used questionnaires, content analysis ofminutes and transcriptions of community sessions and semi-structured interviews to members of EP groups. We present the general list of variables and indicators of empowerment, understood as an open system, as a generator matrix, which can be completed and contrasted from the new contributions arisen during its application. From the literature analysis, most of our proposed indicators were confirmed. The system also includes some unusual indicators in formulations made so far, but that have been validated through our case studies. We consider that this contribution is a good starting point for further research, and a help to greatly enhance the discourse and the value of socio-educational actions and community work

Preliminary results on the assessment of using Venetian blinds as a solar thermal collector in double skin facades in Mediterranean climates

The global trend on energy integration and building efficiency is making both researchers and developers look for technical solutions to use façade surfaces for electricity and/or domestic hot water production. These applications improve the energy performance of the building, but the integration of solar photovoltaic panels or solar thermal collectors into the façade may block visibility to the exterior and may prevent natural light from entering the building, both important comfort factors for building users. This paper presents the preliminary results on the assessment of the thermal performance of a double-skin facade (DSF) with a venetian blind-type of structure used as a solar thermal collector to heat up a circulating fluid by means of computational fluid dynamics (CFD). This type of heat exchange structure would allow for energy recovery and exterior views simultaneously, and can be easily integrated into the façade aesthetical design. For the purposes of this study, the modeled façade is set to be located in Barcelona (Spain), where large solar gains are a constant condition throughout the year, and such large semi-transparent areas as this type of façades can produce significant over-heating in buildings, even during the winter. For the studied façade both the reductions in radiative heat gains entering the building and the heat recovery are evaluated for summer meteorological and solar radiation conditions and numerical results obtained are compared with previous results reported by our research group on a similar DSF model without a façade integrated thermal system.Postprint (author's final draft