Browsing by Keyword "Building"
Now showing 1 - 17 of 17
Results Per Page
Sort Options
Item Assessment of thermal performance and surface moisture risk for a rear-ventilated cladding system for façade renovation(2020-01-24) Arregi, Beñat; Garay, Roberto; Garrido-Marijuan, Antonio; Tecnalia Research & Innovation; EDIFICACIÓN DE ENERGÍA POSITIVAVentilated façade systems, incorporating thermal insulation behind a rear-ventilated cladding, constitute a popular renovation solution in warm European climates. For compliance with building regulations, their energy efficiency is usually obtained through simple onedimensional desktop calculations, which do not consider the impact of the support elements of the cladding penetrating the thermal insulation. This study assesses a ventilated façade system anchored over a solid concrete wall with adjustable stainless steel brackets. One-dimensional calculations are compared against three-dimensional numerical thermal modelling, evaluating the effect of insulation thickness (40–100 mm) and potential gaps in the insulation around anchors. Results indicate low risk of condensation and mould growth over internal surfaces. The additional heat flow induced by stainless steel anchors, which is not considered by simplified calculations, appears lower than for aluminium-based systems but can become significant as insulation levels increase. Ensuring the continuity of insulation around anchors is critical for keeping this additional heat flow at reasonable levels (8–13%). If gaps in the insulation are present around anchors, the additional heat flow increases substantially (25–70%) and pushes effective U-values above 0.4 W/m²K, thus resulting in unforeseen energy consumption and noncompliance with regulatory requirements in many European locations.Item Comparison of nanoclay/polyvinyl alcohol aerogels scale production: Life Cycle Assessment(2021-12) Parascanu, María Magdalena; Esteban-Arranz, Adrián; de la Osa, Ana Raquel; Romero, Amaya; Sánchez-Silva, Luz; ECONOMÍA CIRCULARNowadays, organic aerogels have arisen as promising materials for different applications such as: building, construction, energy among others, due to their low density, high thermal insulation capacity and high porosity. In the recent years multiple procedures to synthesize them have been developed, however, the freeze-drying method has gained more importance, being considered a cost-competitive, eco-friendly, and efficient process. Therefore, it is fundamental to evaluate its environmental impacts for its future implementation as a sustainable industrial process. In this work, a Life Cycle Assessment on the synthesis of nanoclay reinforced polyvinyl alcohol aerogels by freeze-drying has been carried out. Furthermore, the influence of the production scale (laboratory and pilot line) and the functional unit (1 kg and 1 m3) have been studied. Additionally, different upgrading approaches carried out in the pilot line, energy efficiency and production capacity, have been evaluated. Results demonstrated that better environmental impact values were obtained with pilot line aerogel production in comparison to laboratory scale for both functional units. Regarding the different upgrade assessment with the pilot line, it has been concluded that the background processes and the energy consumption are the main causes for the increment in the environmental impact values during the aerogel synthesis.Item Comparison of theoretical heat transfer model with results from experimental monitoring installed in a refurbishment with ventilated facade(2020-01-24) García, Belén Zurro; Goikolea, Beñat Arregi; Martín, José Manuel González; Hernández García, José L.; EDIFICACIÓN DE ENERGÍA POSITIVAOne of the main points to consider when a building is renovated is the improvement of its energy efficiency, minimizing the heat loss through the enclosures and its heating consumption. Under this scope idea a ventilated facade was designed and incorporated in an educational building located in the city of Burgos (Spain). The main objective of this document is a comparison between the theoretical model of heat transfer across the building envelope separating the environment and the interior space, and the heat intake through a linear regression model with installed experimental monitoring. For this it has been necessary to carry out an exhaustive study of the thermal transmission of each one of the materials that make up the thermal envelope of the building, as well as the linear thermal bridges that can be produced before and after the renovation. In addition, thanks to the monitoring installed in the demonstrator building, the interior and exterior temperatures and the heat consumption of each of the radiators is known. In this way expected and real energy savings have been compared.Item Composite polymeric materials as an alternative to aluminium for improved energy performance of ventilated façade systems(2019-11-20) Arregi, Beñat; Elguezabal, Peru; Álvarez, Izaskun; EDIFICACIÓN DE ENERGÍA POSITIVA; ECOEFICIENCIA DE PRODUCTOS DE CONSTRUCCIÓNVentilated façade systems have become an interesting solution in the field of energy efficiency for buildings thanks to their associated improvement in thermal insulation properties. However, differences exist between real and theoretical thermal performance, resulting in an increase of actual energy consumption above predicted values. Part of this mismatch can be attributed to thermal bridges both at support elements and at construction junctions, which are usually overlooked by simplified calculations. The present study assesses the potential for substituting metallic elements with polymeric composite materials for two key elements of ventilated façades: the support subframe of the external cladding and the external window reveals. Thermal, structural and durability properties are specifically assessed. Results show that overall heating energy savings between 7 and 13% can be obtained through the use of pultruded composite profiles at support brackets and window reveals instead of aluminium components. Such solutions are feasible from a mechanical and durability point of view, and the extra costs are offset in a short period through the reduction in heating expenses.Item Curtain Wall with Solar Preheating of Ventilation Air. Full Scale Experimental Assessment(2020-06-30) Garay-Martinez, Roberto; Arregi, Beñat; Tecnalia Research & Innovation; EDIFICACIÓN DE ENERGÍA POSITIVAHeating load in Commercial buildings is highly related with ventilation systems, while at the same time local discomfort in the vicinity of glass walls occurs due to overheating. In this paper, a novel double envelope curtain wall is presented, which extracts heat from the façade by means of a ventilated cavity which is then incorporated to the ventilation air intake. A substantial reduction of heating loads is achieved. Whenever solar gains are not sought, a bypass element allows the natural ventilation of this air cavity, acting as a ventilated façade. An integrated control system with embedded electronics and actuators allows for a smart control of the system. The system is designed for integration with existing rooftop ventilation systems. Design considerations are discussed, and the outcomes of a full-scale experiment conducted in Bilbao (Spain) along 2019 presented.Item Data driven model for heat load prediction in buildings connected to District Heating by using smart heat meters(2022-01-15) Lumbreras, Mikel; Garay-Martinez, Roberto; Arregi, Beñat; Martin-Escudero, Koldobika; Diarce, Gonzalo; Raud, Margus; Hagu, Indrek; Tecnalia Research & Innovation; EDIFICACIÓN DE ENERGÍA POSITIVAAn accurate characterization and prediction of heat loads in buildings connected to a District Heating (DH) network is crucial for the effective operation of these systems. The high variability of the heat production process of DH networks with low supply temperatures and derived from the incorporation of different heat sources increases the need for heat demand prediction models. This paper presents a novel data-driven model for the characterization and prediction of heating demand in buildings connected to a DH network. This model is built on the so-called Q-algorithm and fed with real data from 42 smart energy meters located in 42 buildings connected to the DH in Tartu (Estonia). These meters deliver heat consumption data with a 1-h frequency. Heat load profiles are analysed, and a model based on supervised clustering methods in combination with multiple variable regression is proposed. The model makes use of four climatic variables, including outdoor ambient temperature, global solar radiation and wind speed and direction, combined with time factors and data from smart meters. The model is designed for deployment over large sets of the building stock, and thus aims to forecast heat load regardless of the construction characteristics or final use of the building. The low computational cost required by this algorithm enables its integration into machines with no special requirements due to the equations governing the model. The data-driven model is evaluated both statistically and from an engineering or energetic point of view. R2 values from 0.70 to 0.99 are obtained for daily data resolution and R2 values up to 0.95 for hourly data resolution. Hourly results are very promising for more than 90% of the buildings under study.Item Data driven process for the energy assessment of building envelope retrofits(2020-06-30) Garay-Martinez, Roberto; Arregi, Beñat; Lumbreras, Mikel; Zurro, Belén; Gonzalez, Jose Manuel; Hernandez, Jose Luis; Tecnalia Research & Innovation; EDIFICACIÓN DE ENERGÍA POSITIVAIn the last decades, a growing industry has been created in relation to building envelope retrofits. Linked to the lack of financial capacity of many building owners, innovative instruments such as energy performance contracts have been promoted by public bodies. This kind of instruments require of detailed energy assessment processes in order to define the expected heat load reduction and the associated economic flows between building owners and Energy Services Companies. When dealing with building envelopes, existing methods for building envelope heat loss characterization require of substantial efforts in terms of equipment and time, which makes them difficult to apply in real practice. In this paper, a novel method is proposed based on whole-building heat load assessment by means of heat meters, and analytical calculations of building envelope transmission heat load coefficients. This method, which requires minimal or no additional equipment, can be used over historical data from District Heating systems. It assigns a specific load fraction to building envelope heat transfer and allows to assess the expected reduction due to the building envelope retrofit. Numerical and experimental data is presented based on an educational building in the city of Burgos, Spain.Item Design of a Calorimetric Test Facility to Replicate Real Boundary Conditions in the Gulf Countries(2020-06-30) Garay-Martinez, Roberto; Jayan, Bejay; Arregi, Beñat; Tecnalia Research & Innovation; EDIFICACIÓN DE ENERGÍA POSITIVAThe design and modelling of a calorimetric test infrastructure for building envelopes is performed for the side-by-side assessment of different building envelope systems. The infrastructure is designed for representing transient weather conditions in Middle east. It consists of 3 “cold” experimental chambers and a larger “hot” experimental chamber. All three cold chambers have one equally sized envelope element exposed to the larger chamber. The test facility is designed to allow testing on walls and roofs, where different envelope insulation systems will be installed over a common substrate. Heating and cooling loads of all experimental chambers are calculated, and systematic load differences assessed. Heat flow across test samples and other surfaces in the test are calculated. Insulation levels of envelope surfaces in experimental chambers are specified to provide a good match between heat transfer across test samples and heat input to experimental chambers.Item Designing a generalised reward for Building Energy Management Reinforcement Learning agents(IEEE, 2021-09-08) Martinez, Ruben Mulero; Goikolea, Benat Arregi; Beitia, Inigo Mendialdua; Martinez, Roberto Garay; Mulero, Rubén; Arregi, Beñat; Mendialdua, Iñigo; Garay, Roberto; Solic, Petar; Nizetic, Sandro; Rodrigues, Joel J. P. C.; Rodrigues, Joel J.P.C.; Gonzalez-de-Artaza, Diego Lopez-de-Ipina; Perkovic, Toni; Catarinucci, Luca; Patrono, Luigi; DIGITALIZACIÓN Y AUTOMATIZACIÓN DE LA CONSTRUCCIÓN; EDIFICACIÓN DE ENERGÍA POSITIVA; Tecnalia Research & InnovationThe reduction of the carbon footprint of buildings is a challenging task, partly due to the conflicting goals of maximising occupant comfort and minimising energy consumption. An intelligent management of Heating, Ventilation and Air Conditioning (HVAC) systems is creating a promising research line in which the creation of suitable algorithms could reduce energy consumption maintaining occupants' comfort. In this regard, Reinforcement Learning (RL) approaches are giving a good balance between data requirements and intelligent operations to control building systems. However, there is a gap concerning how to create a generalised reward signal that can train RL agents without delimiting the problem to a specific or controlled scenario. To tackle it, an analysis and discussion is presented about the necessary requirements for the creation of generalist rewards, with the objective of laying the foundations that allow the creation of generalist intelligent agents for building energy management.Item Energy demand prediction for the implementation of an energy tariff emulator to trigger demand response in buildings(2019-08-13) Noyé, Sarah; Saralegui, Unai; Rey, Raphael; Anton, Miguel Angel; Romero, Ander; Tecnalia Research & Innovation; DIGITALIZACIÓN Y AUTOMATIZACIÓN DE LA CONSTRUCCIÓN; EDIFICACIÓN DE ENERGÍA POSITIVABuildings are key actors of the electrical gird. As such they have an important role to play in grid stabilization, especially in a context where renewable energies are mandated to become an increasingly important part of the energy mix. Demand response provides a mechanism to reduce or displace electrical demand to better match electrical production. Buildings can be a pool of flexibility for the grid to operate more efficiently. One of the ways to obtain flexibility from building managers and building users is the introduction of variable energy prices which evolve depending on the expected load and energy generation. In the proposed scenario, the wholesale energy price of electricity, a load prediction, and the elasticity of consumers are used by an energy tariff emulator to predict prices to trigger end user flexibility. In this paper, a cluster analysis to classify users is performed and an aggregated energy prediction is realised using Random Forest machine learning algorithm.Item Energy meters in District-Heating Substations for Heat Consumption Characterization and Prediction Using Machine-Learning Techniques(2020-11-20) Lumbreras, Mikel; Garay, Roberto; Marijuan, Antonio Garrido; Tecnalia Research & Innovation; EDIFICACIÓN DE ENERGÍA POSITIVAThe use of smart energy meters enables the monitoring of large quantity of data related to heat consumption patterns in buildings connected to DH networks. This information can be used to understand the interaction between building and the final users´ without accurate information about building characteristics and occupational rates. In this paper an intuitive and clarifier data-driven model is presented, which couples heat demand and weather variables. This model enables the disaggregation of Space-Heating & Domestic Hot water demand, characterization of the total heat demand and the forecasting for the next hours. Simulations for 53 building have been carried out, with satisfactory results for most of them, reaching R2 values above 0.9 in some of them.Item GIS-3D Platform to Help Decision Making for Energy Rehabilitation in Urban Environments(2019-06-21) Izkara, Jose Luis; Egusquiza, Aitziber; Villanueva, A.; Tecnalia Research & Innovation; LABORATORIO DE TRANSFORMACIÓN URBANAOne of the main current challenges of European cities is to become energy self-sufficient entities. One of the vectors for this challenge is to improve the energy efficiency of the buildings and to promote the generation of renewable energies in the urban environment. The article describes a tool based on GIS-3D technologies to support the identification of the energy rehabilitation potential of neighbourhoods based on the introduction of renewable energies. The platform is based on a urban 3D model that collects the geometry of buildings, together with relevant information for the identification of rehabilitation opportunities (e.g. surfaces, heights, orientations and slopes). The project includes the generation of a cloud-based repository, which incorporates active and passive innovative solutions with metrics that allow the comparison of the solutions and the applicability of them to the real environment. The identification of rehabilitation opportunities combines information resulting from the diagnosis of the current energy performance of the district's buildings with the potential for renewable generation in the area. A multicriteria analysis process facilitates the identification of the most appropriate rehabilitation solutions for the analysed environment based on different criteria as energy, cost or applicability. The result can be visualized through a web tool that combines 2D and 3D information, with comparative information in a quantitative and geo-referenced manner. The flexibility of the architecture allows the application of the same approach to different urban challenges as the application of energy conservation measures to protected historic urban areas.Item Life Cycle Assessment of a solar thermal system in Spain, eco-design alternatives and derived climate change scenarios at Spanish and Chinese National levels(2019-05) Albertí, Jaume; Raigosa, Juliana; Raugei, Marco; Assiego, Rafael; Ribas-Tur, Joan; Garrido-Soriano, Núria; Zhang, Linghui; Song, Guobao; Hernández, Patxi; Fullana-i-Palmer, Pere; PLANIFICACIÓN ENERGÉTICASolar thermal energy is considered a ‘clean’ form of energy; however, environmental impacts occur during its life-cycle. The present work compares the environmental performance of two scenarios: a solar thermal system for providing domestic hot water (DHW) used in conjunction with a traditional natural gas heating system, and the natural gas heating system on its own. Weak points are found and different eco-design scenarios are evaluated in order to achieve a more circular economy. In addition, the authors explore what would be the national Greenhouse Gas emission reduction potential of a wider use of domestic solar hot water systems (DSHW) in China's and Spain's built environment. In this case, five displacement methods are suggested to show how the emissions reduction vary. Through a review of the state of the art and a Life Cycle Assessment of a solar system the two scenarios are assessed. Some impact categories, such as global warming, suggest a markedly better performance of the solar system (-65%). However, weak points in the solar solution have been identified as there is an increase of impacts in cases such as acidification (+6%) and eutrophication (+61%), mostly due to the metals used. The components with higher environmental impact are the collector, the tank, and the copper tubes. The reduction of national emissions by promoting DSHW depends on the actual displaced technology/ies. The consequences on national emissions reduction depending on these choices are assessed. The potential reduction of emissions, if 30% of the DHW were covered with solar sources, would be between 0.38% and 0.50% in the case of Spain and between 0.12% and 0.63% in China.Item Novel method for an optimised calculation of modal analysis of girder bridge decks(2022-07) Gaute-Alonso, Alvaro; Garcia-Sanchez, David; Ramos-Gutierrez, Óscar Ramón; Tecnalia Research & Innovation; E&I SEGURAS Y RESILIENTESA correct modal analysis of girder bridge decks requires a correct characterisation of the deformation of their cross-section, governed by the longitudinal bending of the girders and the transverse bending of the slab. This paper presents a novel method that allows the modal analysis of girder bridge decks by applying a matrix formulation that reduces the structural problem to one degree of freedom for each girder: the deflection at the centre of the beam span. A parametric study is presented that analyses the structural response of 64 girder bridge decks. The study compares the dynamic structural response obtained by the proposed method with that obtained by traditional grillage calculation methods. The method is experimentally contrasted by a dynamic load test of a full-scale girder bridge. As a result of the analysis, the proposed method reflects adequate convergence with the experimental dynamic structural response. The use of the proposed novel analysis method contributes to the intelligent modelling process for the analysis of the dynamic behaviour of bridges opening the way to easily feed a Digital Twin accelerating the demands of the Decision Support System in real time.Item Parametric assessment of a building active façade by means of a combined metallic sandwich panel with an unglazed solar collector(2019-09) Elguezabal, Peru; Lopez, Alex; Blanco, Jesús María; Chica, José Antonio; ECOEFICIENCIA DE PRODUCTOS DE CONSTRUCCIÓN; SGThe building sector has a poor performance in terms of energy efficiency and is looking for alternatives to reduce the use of fossil fuels on building use stage. Renewables are unlimited and solar thermal energy is a technology with a demonstrated potential. The façade is a key element able to harness renewable energy coming from the sun becoming in an Active Solar Thermal Façade (ASTF). The main purpose of this study is the development of a parametric study using a numerical model to analyze the behavior of an unglazed solar collector. Thus, evaluating different design and meteorological parameters to show their influence on the heat transfer and the efficiency. The study shows that solar irradiation and mass flow are the most influential on thermal difference. However, for the efficiency ambient temperature and inlet temperature both are the most influencing ones. In brief, a set of parameters have a significant influence on the behavior of the ASTF that are fully governed by environmental conditions. Nevertheless, there are some other parameters that can be controlled during the operation. The challenge is to make a continuous configuration of this adaptable values depending on the external situation to achieve a higher performance for the ASTF.Item Plotting a path to reduce the energy performance gap(2019-04-08) de Agustin-Camacho, Pablo; Romero-Amorrortu, Ander; Kowalska, Agnieszka; Tecnalia Research & InnovationImproving energy efficiency performance in buildings is a major priority for the European Commission, with a target of achieving 20 percent energy savings by 2020. The EU promotes solutions which reduce energy consumption in the building sector to achieve this, an area which forms the primary research focus for the MOEEBIUS projectItem Temporary cable force monitoring techniques during bridge construction-phase: the Tajo River Viaduct experience: the Tajo River Viaduct experience(2022-12) Gaute-Alonso, Alvaro; Garcia-Sanchez, David; Alonso-Cobo, Carlos; Calderon-Uriszar-Aldaca, Iñigo; Tecnalia Research & Innovation; E&I SEGURAS Y RESILIENTESThis article deals with the comparative analysis of current cable force monitoring techniques. In addition, the experience of three cable stress monitoring techniques during the construction phase is included: (a) the installation of load cells on the active anchorages of the cables, (b) the installation of unidirectional strain gauges, and (c) the evaluation of stresses in cables applying the vibrating wire technique by means of the installation of accelerometers. The main advantages and disadvantages of each technique analysed are highlighted in the Construction Process context of the Tajo Viaduct, one of the most singular viaducts recently built in Spain.