24 research outputs found
Economic appraisal of energy efficiency renovations in tertiary buildings
This is an ACCEPTED VERSION of the following published document: Patiño Cambeiro, F., Armesto, J., Bastos, G., Prieto López, J. I. & Patiño
Barbeito, F. (2019). Economic appraisal of energy efficiency renovations in
tertiary buildings. Sustainable Cities and Society, 47. https://
doi.org/10.1016/j.scs.2019.101503[Abstract]
The EU, through its energy policy, has established a renovation rate of 3% for public buildings. This activity has a key role in achieving European targets regarding reducing energy consumption and greenhouse gas emissions. Moreover, the promotion of building renovations would reduce energy dependence and unemployment in the EU. The present work is aligned with the recently updated EPBD in the energy policy through an economic evaluation of energy renovations of eleven tertiary buildings. These buildings belong to three Spanish university campuses, and most of these buildings were built under the previous Spanish building code, which was enforced between 1979 and 2006. While revisions to the envelope are typically cost prohibitive, active measures can achieve a significant reduction in energy consumption and energy costs. The investment is recouped in 1.1–6.7 years for a new lighting installation and 0.7–7.7 years for a natural gas or biomass boiler. For the optimal combinations, typical reductions in primary energy consumption range between 12% and 48%. In the current scenario of limited economic resources, the data provided in this work can be used to prioritize expenditures in energy renovations from environmental or economic approaches
Isolamento térmico de fachadas:: redução do consumo energético de edificações para Zona Bioclimática 2
Currently the world energy and environmental scenario is in a critical state, with increasing energy demand. Its generation still depends on exhaustible and polluting natural resources. The high electric consumption directed to the artificial climatization is the main target of the study. The purpose of this paper is to analyze the thermal insulation of the building, External Thermal Insulation Composite System (Etics), against the hot climate of the Bioclimatic Zone 2 region in the analyzed period, through normative calculations and temperature measurements in prototypes executed in masonry, in the city of Lajeado, RS, Brazil. As a result, it was obtained a reduction of 81% in the thermal transmittance (U), and 68% of the energy consumption of the prototype with Etics, which considerably interfered in the design of air conditioners. The system efficiency was evident when the internal temperature comparative graphs were analyzed, with the Etics prototype exhibiting more mild and stable temperatures, compared to the external environment and to the non-insulated prototype. The analyses demonstrate a considerably positive intervention of the Etics in the thermal performance, for Bioclimatic Zone 2.Atualmente, o cenário mundial energético e ambiental encontra-se em um estado crÃtico, com demanda de energia cada vez maior e geração ainda dependente de recursos naturais esgotáveis e poluentes. O elevado consumo elétrico direcionado àclimatização artificial é o principal alvo do estudo. O intento deste artigo é analisar o isolamento térmico pelo exterior da edificação, External Thermal Insulation Composite System (Etics), ante o clima quente da região da Zona Bioclimática 2 no perÃodo analisado, por meio de cálculos normativos e de medições de temperaturas em protótipos executados em alvenaria convencional, na cidade de Lajeado, RS, Brasil. Como resultado, obteve-se redução de 81% da transmitância térmica (U), e 68% do consumo energético do protótipo com Etics, interferindo consideravelmente no dimensionamento de condicionadores de ar. A eficiência do sistema ficou evidente quando analisados os gráficos comparativos de temperaturas internas, utilizando o protótipo Etics. Constatou-se temperaturas mais amenas e estáveis, em relação ao ambiente externo e ao protótipo sem isolamento. As análises demonstram uma intervenção consideravelmente positiva do Etics no desempenho térmico para a Zona Bioclimática 2
Development of natural and innovative material for application as thermal insulation in buildings
The advent of new technologies related to thermal insulation systems in civil construction helps buildings become more efficient, reducing their consumption of electric energy through air conditioning, and providing thermal comfort to users. The research aims to develop a facade cladding board for buildings, with thermal insulation starting from vacuum, and corn cob. Facade coatings with mortar finish were developed, filling them with developed materials. Three prototypes were executed in masonry of ceramic blocks, with dimensions of 60x60x64,0 cm. The Field Logger 512K (Lite) and PT100 sensors were used for data collection of external temperature and internal temperature of the prototypes. Solar radiation data were collected by the university weather station, model Davis-6450. It is worth noting the average internal temperature reduction in Prototype 2 and 3, compared to 1 (without isolation), which was 2.74 ° C and 8.05 ° C
BIOCLIMATIC STRATEGIES FOR THE CITY OF LAJEADO/RS-BRAZIL, USING DATA ANALYSIS OF REGIONAL CLIMATE
The city of Lajeado is located at the Vale do Taquari region, 120 km away from Porto Alegre, the capital of Rio Grande do Sul (RS) state, Brazil. Locally, the civil construction industry has grown 517.7% between the years of 1991 and 2011. Basic information concerning the choice of materials suitable to the climate, and early studies focused on the research of natural ventilation, are denied in the development of projects of buildings. Bioclimatic Charts are being developed for Brazil, in which architectural strategies can be determined for application in building project design. The study here shown is about acquisition of climate data for the city of Lajeado in southern of Brazil, during the period of 2004 to 2015, including data processing and analysis using BioEstat statistic software and data plotting to the bioclimatic chart with the use of the Sol-ar software. The results show how building design strategies like passive solar heating and thermal inertia, as well as an adequate application of construction materials, must be used more, as to working with thermal isolation in cold and hot days
Aplicación de técnicas actuales de diseño y fabricación en la construcción de la arquitectura residencial: del centÃmetro al milÃmetro.
Es bien conocido, ahora, que la bonanza económica experimentada en España durante
el perÃodo 1995-2007 se caracterizó por estar apoyada en sectores productivos que
demandaban mano de obra no cualificada y servicios que aportaban escaso valor añadido.
Mientras tanto, durante este perÃodo, el sector industrial fue perdiendo protagonismo y
consecuentemente tuvo un papel menos relevante en el peso de la economÃa nacional. De
entre estos sectores productivos, es el de la construcción el más representativo y agudizado
todavÃa más el problema en el apartado correspondiente a la construcción residencial.
Consecuencia de lo expuesto es que el sector de la construcción con gran crecimiento
en ese perÃodo, no sintió la necesidad de la implantación de polÃticas basadas en la formación,
productividad, calidad o eficiencia; de ahà que el desplome económico actual incida
directamente en el sector, ahora obsoleto con respecto a otros sectores, a consecuencia de
estos déficits. No ha sucedido asà con el sector industrial; la fuerte competencia unida al
instinto de supervivencia y necesidad de crecimiento ha provocado estrategias de éxito
orientadas hacia la introducción de técnicas y herramientas innovadoras de gestión y
producción en busca de la competitividad de sus sistemas productivos.
Pues bien, la existencia de dos sectores, (sin relación hasta el momento, el de la
construcción y el industrial; uno obsoleto y en la actualidad con muchas dificultades y el otro,
el industrial, sorteando con resultados discretos la crisis, debido en gran medida a la eficacia
de sus estructuras productivas) ha dado lugar al razonamiento con el que se plantea esta tesis
y que en esencia propone, con el objeto de mejorar el producto final y los sistemas de trabajo,
la adaptación al sector de la construcción de técnicas del sector industrial, ya contrastadas y
validadas.
Para ello se propone el análisis de estas técnicas existentes y la selección de aquellas
que mejor encajen y se adapten a la industria de la construcción, en particular a la residencial
en la que el cliente, que normalmente coincide en la persona del promotor, busca una solución
y no un servicio. Una vez seleccionadas la que se entienden idóneas, la propuesta consiste en
la construcción de un modelo racional, integrador de las actividades principales de una obra de
este tipo.
El modelo elegido, consecuencia de los análisis y razonamientos reflejados en la
investigación, está basado en los criterios que aportan los postulados de la filosofÃa Lean, de
fuerte y relativamente reciente implantación en los sectores industriales más competitivos.
Lean además de coincidir con los criterios de esta tesis en lo relativo a la reducción de
errores, aporta a los objetivos mejoras en la calidad del producto terminado y favorece las
relaciones en el trabajo. La sustitución del inexacto centÃmetro, unidad actual de tolerancia de
las desviaciones admisibles en la construcción, por el preciso milÃmetro es una de las metas a
conseguir y reflejo de lo acertado de la aplicación.
La elección de este modelo de gestión, orientado hacia la entrega del máximo valor
para el cliente con el mÃnimo de recursos, el diseño de su estructura e implantación en el
sector se considera la aportación novedosa de la tesis.
Los agentes que componen la estructura del sistema, en contraposición al de
producción actual, pertenecerán a grupos integrados, suscribirán acuerdos, adoptarán
polÃticas de mejora continua, intercambiarán información y participarán en conjunto, con el
objetivo de un producto final en lÃnea con los parámetros establecidos en los requerimientos
del proyecto. Para ello, y en consonancia con los criterios de la filosofÃa Lean, la tesis propone
el diseño de los documentos y los entornos de trabajo que organizan, comprometen e integran
a estos agentes en equipos organizados según su rol en el proceso, su nivel de responsabilidad
y poder de decisión.
La gestión de estos entornos se organiza a partir de un núcleo principal en el proceso
formado por una trÃada, el equipo de dirección del proyecto, presente en cualquiera de las
etapas de la construcción; su principal consideración reside en la identificación de los intereses
del proyecto en su conjunto, por encima de sus intereses individuales y está integrada por el
promotor, el equipo de diseño y el contratista principal, que mediante una relación
contractual, recogida en el modelo de contrato propuesto por esta tesis, plantean una
colaboración que requiere del método IPD para su desarrollo.
Por último, se exponen las ventajas y los beneficios que suponen el uso y aplicación del
modelo y las herramientas complementarias de apoyo que facilitan las actuaciones, desarrollo
y control de obra: TIC´s, PDM, BIM…. Para una mejor comprensión en su uso, se complementa
la investigación con ejemplos de aplicaciones prácticas y reales de obra
Perspectives on Near ZEB Renovation Projects for Residential Buildings: The Spanish Case
EU regulations are gradually moving towards policies that reduce energy consumption and its environmental impact. To reach this goal, improving energy efficiency in residential buildings is a key action line. The European Parliament adopted the Near Zero-Energy Building (nZEB) as the energy efficiency paradigm through Directive 2010/31/EU, but a common technical and legislative framework for energy renovations is yet to be established. In this paper, the nZEB definition by COHERENO was adopted to evaluate several energy renovation packages in a given building, which is also representative of the Spanish building stock. Global costs are calculated for all of them following EPBD prescriptions. Two economic scenarios are analysed: with entirely private funding and with the current public financial incentives, respectively. The results show the divergence between optimum solutions in terms of costs and of minimum CO2 footprint and maximum energy saving. Moreover, in the absence of enough incentives, some inefficient renovations could achieve a global cost close to the optimal cost. The optimum solution both in terms of energy performance and global costs was carried out and described
Multidisciplinary Energy Assessment of Tertiary Buildings: Automated Geomatic Inspection, Building Information Modeling Reconstruction and Building Performance Simulation
There is an urgent need for energy efficiency in buildings within the European framework, considering its environmental implications, and Europe’s energy dependence. Furthermore, the need for enhancing and increasing productivity in the building industry turns new technologies and building energy performance simulation environments into extremely interesting solutions towards rigorous analysis and decision making in renovation within acceptable risk levels. The present work describes a multidisciplinary approach for the estimation of the energy performance of an educational building. The research involved data acquisition with advanced geomatic tools, the development of an optimized building information model, and energy assessment in Building Performance Simulation (BPS) software. Interoperability issues were observed in the different steps of the process. The inspection and diagnostic phases were conducted in a timely, accurate manner thanks to automated data acquisition and subsequent analysis using Building Information Modeling based tools (BIM-based tools). Energy simulation was performed using Design Builder, and the results obtained were compared with those yielded by the official software tool established by Spanish regulations for energy certification. The discrepancies between the results of both programs have proven that the official software program is conservative in this sense. This may cause the depreciation of the assessed buildings
Multidisciplinary Energy Assessment of Tertiary Buildings: Automated Geomatic Inspection, Building Information Modeling Reconstruction and Building Performance Simulation
The authors would like to add the student Luis Gandarela Campos, from the University of Vigo, that contributed in some technical computations, in the Acknowledgement Section of their paper published in Energies [1].[...
La casa Varela de Alejandro de la Sota, prototipo prefabricado modular
En el contexto de carencia de recursos y aislamiento de la posguerra española, la necesaria reconstrucción del
paÃs se veÃa lastrada por los sistemas de producción obsoletos de las empresas, la escasez de materiales y la
falta de mano de obra especializada. Estas mismas causas eran el origen del retraso en la industrialización y la
falta de desarrollo cientÃfico-técnico de los procesos constructivos, sin los que no era posible establecer un
control de calidad riguroso y el desarrollo de sistemas constructivos prefabricados que permitiesen acelerar los
procesos constructivos y sistematizar la producción.
La labor pionera del Instituto Técnico de la Construcción y la Edificación dirigido por Eduardo Torroja en cuanto a
la racionalización cientÃfica de los elementos y sistemas constructivos, se vio secundada por las iniciativas
personales de arquitectos que trataron de introducir sistemas prefabricados en sus proyectos tal y como en ese
momento se estaba haciendo en paÃses como Estados Unidos, Francia, Italia o Alemania.
La presente comunicación pretende destacar la labor pionera de Alejandro de la Sota en el campo de la
prefabricación modular en la España de los años cincuenta y sesenta, a través de su contextualización y análisis.
En este perÃodo De la Sota centró su actividad en el concepto de Arquitectura FÃsica, una arquitectura basada en
la prefabricación, la ligereza, la modularidad y la industrialización de todos sus componentes. El proyecto de la
Casa Varela en Collado Mediano fue el punto de partida de una intensa reflexión y el prototipo de una serie de
proyectos de mayor escala basados en el uso de los prefabricados de hormigón producidos por la compañÃa
Horpresa como origen, módulo y sistema constructivo y estructural. A su condición de prototipo ha de añadirse
que fue el único proyecto que llego a completarse de esta serie y una obra pionera por su claridad conceptual y
su radical planteamiento y materialidad.
Palabras clave: Sota (de la), Varela, Arquitectura, Prefabricación, Modularidad
Admixtures in Cement-Matrix Composites for Mechanical Reinforcement, Sustainability, and Smart Features
For more than a century, several inclusions have been mixed with Portland cement—nowadays the most-consumed construction material worldwide—to improve both the strength and durability required for construction. The present paper describes the different families of inclusions that can be combined with cement matrix and reviews the achievements reported to date regarding mechanical performance, as well as two other innovative functionalities of growing importance: reducing the high carbon footprint of Portland cement, and obtaining new smart features. Nanomaterials stand out in the production of such advanced features, allowing the construction of smart or multi-functional structures by means of thermal- and strain-sensing, and photocatalytic properties. The first self-cleaning concretes (photocatalytic) have reached the markets. In this sense, it is expected that smart concretes will be commercialized to address specialized needs in construction and architecture. Conversely, other inclusions that enhance strength or reduce the environmental impact remain in the research stage, in spite of the promising results reported in these issues. Despite the fact that such functionalities are especially profitable in the case of massive cement consumption, the shift from the deeply established Portland cement to green cements still has to overcome economic, institutional, and technical barriers