Browsing by Author "Garay, Roberto"
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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 Calibration procedures for multidimensional heat transfer models based on on-site experimental data(2015-11-01) Garay, Roberto; Uriarte, Amaia; Apraiz, Inés; Martinez, Roberto Garay; Arrien, Amaia Uriarte; Egaña, Ines Apraiz; Tecnalia Research & Innovation; EDIFICACIÓN DE ENERGÍA POSITIVAAn experimental and numerical approach to the characterization of thermal bridges is presented, based on on-site taken measurements. Commonly on-site applied numerical thermal assessments perform one-dimensional heat transfer analysis over planar elements such as facades. However, it is well known that within thermal bridges in a building one-dimensional heat transfer analysis cannot be applied. A procedure is proposed, based on the creation of a numerical 2D thermal model which is calibrated against experimental data from several temperature and heat flux sensors which are located at specific points in the thermal bridge elements. Results of one particular implementation of this method are discussed.Item DESIGN OF CONSUMMER THERMAL SUBSTATIONS FOR THE INTEGRATION OF DISTRIBUTED SOLAR TECHNOLOGIES IN DISTRICT HEATING SYSTEMS(2018-04) Sánchez Zabala, Víctor; Garay, Roberto; Tecnalia Research & InnovationIn most cases, building service designers choose between Solar thermal (ST) and District Heating (DH) technologies for their integration in buildings. By doing so, only a fraction of the buildings within a particular district is used for ST, while at the same time energy intensity in DH networks can be reduced. In some cases, building-integrated solar thermal systems are connected to DH networks by means of dedicated pipes. In all these cases, sub-optimal situations are reached with lower fraction of renewable heat, reduced network strength and/or additional heat losses. In this paper, a consummer substation concept is proposed with reversible heat flow and net metering, which avoids local thermal storage in the solar loop. Adaptations required for multi-dwelling buildings are presented.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 Disaggregation process for dynamic multidimensional heat flux in building simulation(2017-08-01) Garay, Roberto; Riverola, Alberto; Chemisana, Daniel; Martinez, Roberto Garay; Tecnalia Research & InnovationHeat transfer across envelopes (façade, roof, glazed areas) represents a big share of the energy flow within the heat balance of buildings. This paper focuses on areas of the envelope where multi-dimensional heat transfer occurs. These areas are commonly defined as thermal bridges, due to a localized reduction of thermal resistance of constructions in these places. This paper reviews common standardized methods to assess heat transfer in buildings, under various modelling assumptions: one-dimensional, multi-dimensional, steady state and dynamic. Within presently developed modelling and assessment methods, a need for improvement has been identified over existing methods for the thermal assessment of multi-dimensional heat transfer under dynamic conditions. A phasorial approach to differential heat transfer in thermal bridges has been developed, which serves as the dynamic extension of steady-state thermal bridge coefficients. This formulation is applied to the junction of a masonry wall with a concrete slab.Item District Heating De-Carbonisation in Belgrade. Multi-Year transition plan(2020-11-20) Marijuan, Antonio Garrido; Garay, Roberto; Lumbreras, Mikel; Vladic, Ljubisa; Savić, Radmilo; Savic, Radmilo; EDIFICACIÓN DE ENERGÍA POSITIVA; Tecnalia Research & InnovationA large share of the city of Belgrade is heated by a District Heating network. Established in 1965, the network delivers 3.6 TWh to more than 20 million square meters of households industries and businesses, by means of a 1460km-long network. The system has been continuously upgraded and adapted to new technologies and already operates at relatively low temperature, with modernized substations. However, the delivered heat is still produced mainly by means of carbon intensive technologies. Conscious of the need to de-carbonise the city, a multi-year transition plan was established, where large investments have been secured, comprising greater interconnection levels, installation of large solar thermal plants and waste incineration plants, and the conversion of a power plant into CHP, among others. In this paper, the criteria for the selection of the technologies, the identification of enabling investments, interaction with stakeholders, securing of financing, and status of the plan are presented. After the execution of the de-carbonisation roadmap, it is expected that the DH system will reduce its carbon intensity by 50%.Item Energy & economic assessment of façade-integrated solar thermal systems combined with ultra-low temperature district-heating(2020-10) Lumbreras, Mikel; Garay, Roberto; Tecnalia Research & InnovationThis paper conducts an energy and economic assessment of District Heating (DH) integrated Solar Thermal (ST) systems. An implementation with building-integrated ST collectors coupled to a Low Temperature District Heating (LTDH) system is studied, with special focus on unglazed collectors. ST heat is exploited in the building through direct use, while excess heat is delivered to the network. A novel control strategy for heat flows in the system is proposed. A meta-analysis of several DH configurations, interconnection schemes and installed ST capacity is performed in three different climates: Sevilla (Spain), Bordeaux (France) & Copenhagen (Denmark). Heat loads corresponding to buildings with various insulation levels and domestic hot water loads are assessed in hourly simulations. The proposed interconnection concept provides a variety of connection modes to the DH network, allowing up to a 50% increase in the provision of solar heat compared to an isolated ST system. Positive Return of Investment (ROI) for such a setup is achieved in 22% of the studied cases. The DH network is found to be a suitable heat sink in up to 25% of the buildings with ST systems installed.Item Energy efficiency achievements in 5 years through experimental research in KUBIK(2015-06) Garay, Roberto; Chica, José Antonio; Apraiz, Inés; Campos, José María; Tellado, Borja; Uriarte, Amaia; Sánchez, V.; Tecnalia Research & Innovation; SG; DIGITAL ENERGY; EDIFICACIÓN DE ENERGÍA POSITIVAThe European construction sector (a fragmented SMEs dominated business with high economic and environmental impact and high technological inertia) faces a major challenge to reduce the emissions by almost 90% in 2050. This requires new innovative solutions and services to be rapidly implemented in the market. Research Infrastructures that give support for later-stage developments (high Technology Readiness Levels) can play a relevant role in both the technological development and market introduction of construction products for energy efficient buildings. The following paper describes such an infrastructure (KUBIKby (Tecnalia)) located in Bilbao (Spain) and its major outcomes in the period 2011-2015.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 Experimental Thermal Performance Assessment of a Prefabricated External Insulation System for Building Retrofitting(ELSEVIER SCIENCE BV, SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS, 2017) Garay, Roberto; Arregi, Beñat; Elguezabal, PeruExternal Thermal Insulation Composite Systems (ETICS) are increasingly used for the energy-efficient retrofit of buildings. This paper evaluates the in-situ thermal performance of a prefabricated composite panel made of PIR and concrete, by full scale testing of a prototype installed at the KUBIK test facility. Experimental results from measurement show a reduction in the thermal resistance of the ETICS assembly compared to theoretical design values. A number of phenomena have been identified causing multidimensional heat flow of conductive and convective nature,such as thermal bridges at floor slabs and anchors, and thermal bypass of the insulation causing airflow behind the ETICS.Item Experimentation under real performing conditions of a highly integrable unglazed solar collector into a building façade(2017-09) Elguezabal, P.; Garay, Roberto; Martin, K.; ECOEFICIENCIA DE PRODUCTOS DE CONSTRUCCIÓN; Tecnalia Research & InnovationIn the current context of moving towards more sustainable construction, advanced façade systems that integrate solar collecting devices represent a commitment with future trends that combine renewable technologies with building skins. This paper describes a real experience when combining a novel unglazed solar collector based on sandwich panel technology, a heat pump and a controller that manages the different operation modes. Installed in the Kubik by Tecnalia testing building in northern Spain, the system has been monitored for several months in 2016, under an energy efficiency scope. The study will present measured values regarding the yield of the collector, performance of the heat pump and general efficiencies.Item Full scale experimental performance assessment of a prefabricated timber panel for the energy retrofitting of multi-rise buildings(2017-09) Garay, Roberto; Benito Ayucar, Josu; Arregi Goikolea, Beñat; Garay Martinez, Roberto; Tecnalia Research & Innovation; Materiales Construcción Azpeitia; EDIFICACIÓN DE ENERGÍA POSITIVAA prefabricated timber façade system is presented for the energy retrofitting of buildings. Large panel dimensions facilitate the installation of this system, with reduced disturbance to building users and increased overall quality in terms of thermal bridge mitigation and air tightness of architectural junctions. A full scale proof of concept test is performed, where several prefabricated timber panels were installed over a pre-existing brick façade, their junctions tested, and the differential thermal performance of the system is evaluated. It is concluded that the overall thermal performance of the system is satisfactory in terms of overall U-value, thermal bridge coefficient and, temperature factor. Furthermore, and based on experimentally obtained data, a dynamic characterization of the harmonic thermal response of the system is performed.Item Hybrid numerical and experimental performance assessment of structural thermal bridge retrofits(2018) Garay, Roberto; Garay Martinez, Roberto; Tecnalia Research & InnovationA methodological approach to the multi-dimensional heat transfer assessment of building envelopes is performed. The proposed method is particularly focused on thermally weak points in envelope-structure junctions and the assessment of envelope retrofit alternatives. Thermal performance in these spots is seldom assessed in energy audit processes, although it is one of the main heat loss paths in many insulated façade solutions. An envelope-slab junction case is presented, where multi-dimensional heat transfer occurs. The present paper proposes a methodology which allows for a hybrid experimental and numerical performance assessment in such circumstances. A numerical model is calibrated against experimental data, which is then modified to reflect various envelope retrofit solutions. Several possible analysis procedures are proposed, based on the capacities of transient thermal models.Item NUEVO SISTEMA CONSTRUCTIVO SOSTENIBLE CON AISLANTE DE FIBRA DE CÁÑAMO(Congreso Euro-Americano REHABEND 2016, 2016-05-24) Fernandez, Idurre; Garay, Roberto; Urrea, Raul; Aramburu, Amaia; Madariaga, IgorEste artículo presenta el desarrollo de un nuevo sistema constructivo de fachada basado en un núcleo sostenible. Como resultado del trabajo desarrollado, se ha diseñado un panel estructural prefabricado de madera que integra entre sus componentes la fibra de madera con la fibra de cáñamo como aislantes principales. Los beneficios de la solución, ofreciendo inercia térmica y regulando la humedad interna, combinados con un aislante transpirable, dotan a la solución de un comportamiento muy competitivo en relación a las soluciones de baja energía embebida. Por otra parte, se exponen los principales retos afrontados en el desarrollo del sistema, en lo que respecta, tanto a la propia caracterización del producto como a la certificación de producto, los cuales representan un enorme hándicap a la hora de implementar la solución y comercializarla en el mercado. Mediante la experimentación desarrollada a escala real, se obtendrán datos del comportamiento del panel que validarán el nuevo sistema y permitirán caracterizar el panel, de cara a delimitar su uso y poder comercializar el producto. Finalmente, para poder afrontar esta fase de comercialización con éxito, se ha definido una vía de certificación de producto, que pretende establecer un precedente de éxito que promueva el desarrollo de soluciones constructivas basadas en materiales sostenibles, superando las barreras actuales existentes en lo que respecta a la comercialización e introducción en el mercado de sistemas constructivos basados en materiales sostenibles.Item Passive solar collector module for building facades (DE)(2009-12-29) Amundarain, Aitor; Campos, José María; Chica, José Antonio; Meno, Sandra; Uriarte, Amaia; Garay, Roberto; Herrero, Julio Cesar; Oliver, Marc; Pérez, Sergio; Elguezabal, Peru; Romero, Ander; Apraiz, InésThe invention relates to a passive solar collector module for building facades comprising a transparent panel and a heat absorbing panel, separated from one another by an air chamber and assembled in a frame; an upper air conduit for communicating the air chamber with an area close to the ceiling of a story of a building; a lower air conduit for communicating the air chamber with an area close to the floor of a story of a building; an environmental air inlet in the lower part of the module and a heated air outlet and in the upper part of the module; a first air directing system operable such that in a first position it blocks the air outlet and in a second position it blocks the upper air conduit; a second air directing system operable such that in a first position it blocks the lower air conduit, in a second position it blocks the air flow towards the air outlet and in a third position it does not block either the lower air conduit or the air flow towards the air outlet.Item Passive solar collector module for building facades (EPO)(2009-12-29) Amundarain, Aitor; Campos, José María; Chica, José Antonio; Meno, Sandra; Uriarte, Amaia; Garay, Roberto; Herrero, Julio Cesar; Oliver, Marc; Pérez, Sergio; Elguezabal, Peru; Romero, Ander; Apraiz, InésThe invention relates to a passive solar collector module for building facades comprising a transparent panel and a heat absorbing panel, separated from one another by an air chamber and assembled in a frame; an upper air conduit for communicating the air chamber with an area close to the ceiling of a story of a building; a lower air conduit for communicating the air chamber with an area close to the floor of a story of a building; an environmental air inlet in the lower part of the module and a heated air outlet and in the upper part of the module; a first air directing system operable such that in a first position it blocks the air outlet and in a second position it blocks the upper air conduit; a second air directing system operable such that in a first position it blocks the lower air conduit, in a second position it blocks the air flow towards the air outlet and in a third position it does not block either the lower air conduit or the air flow towards the air outlet.Item Passive solar collector module for building facades (ES)(2009-12-29) Amundarain, Aitor; Campos, José María; Chica, José Antonio; Meno, Sandra; Uriarte, Amaia; Garay, Roberto; Herrero, Julio Cesar; Oliver, Marc; Pérez, Sergio; Elguezabal, Peru; Romero, Ander; Apraiz, InésThe invention relates to a passive solar collector module for building facades comprising a transparent panel and a heat absorbing panel, separated from one another by an air chamber and assembled in a frame; an upper air conduit for communicating the air chamber with an area close to the ceiling of a story of a building; a lower air conduit for communicating the air chamber with an area close to the floor of a story of a building; an environmental air inlet in the lower part of the module and a heated air outlet and in the upper part of the module; a first air directing system operable such that in a first position it blocks the air outlet and in a second position it blocks the upper air conduit; a second air directing system operable such that in a first position it blocks the lower air conduit, in a second position it blocks the air flow towards the air outlet and in a third position it does not block either the lower air conduit or the air flow towards the air outlet.Item Passive solar collector module for building facades (FR)(2009-12-29) Amundarain, Aitor; Campos, José María; José Antonio, Chica; Meno, Sandra; Uriarte, Amaia; Garay, Roberto; Herrero, Julio Cesar; Oliver, Marc; Pérez, Sergio; Elguezabal, Peru; Romero, Ander; Apraiz, InésThe invention relates to a passive solar collector module for building facades comprising a transparent panel and a heat absorbing panel, separated from one another by an air chamber and assembled in a frame; an upper air conduit for communicating the air chamber with an area close to the ceiling of a story of a building; a lower air conduit for communicating the air chamber with an area close to the floor of a story of a building; an environmental air inlet in the lower part of the module and a heated air outlet and in the upper part of the module; a first air directing system operable such that in a first position it blocks the air outlet and in a second position it blocks the upper air conduit; a second air directing system operable such that in a first position it blocks the lower air conduit, in a second position it blocks the air flow towards the air outlet and in a third position it does not block either the lower air conduit or the air flow towards the air outlet.Item Passive solar collector module for building facades (GB)(2009-12-29) Amundarain, Aitor; Campos, José María; Chica, José Antonio; Meno, Sandra; Uriarte, Amaia; Garay, Roberto; Herrero, Julio Cesar; Oliver, Marc; Pérez, Sergio; Elguezabal, Peru; Romero, Ander; Apraiz, InésThe invention relates to a passive solar collector module for building facades comprising a transparent panel and a heat absorbing panel, separated from one another by an air chamber and assembled in a frame; an upper air conduit for communicating the air chamber with an area close to the ceiling of a story of a building; a lower air conduit for communicating the air chamber with an area close to the floor of a story of a building; an environmental air inlet in the lower part of the module and a heated air outlet and in the upper part of the module; a first air directing system operable such that in a first position it blocks the air outlet and in a second position it blocks the upper air conduit; a second air directing system operable such that in a first position it blocks the lower air conduit, in a second position it blocks the air flow towards the air outlet and in a third position it does not block either the lower air conduit or the air flow towards the air outlet.Item Passive solar collector module for building facades (IT)(2009-12-29) Amundarain, Aitor; Campos, José María; Chica, José Antonio; Meno, Sandra; Uriarte, Amaia; Garay, Roberto; Herrero, Julio Cesar; Oliver, Marc; Pérez, Sergio; Elguezabal, Peru; Romero, Ander; Apraiz, InésThe invention relates to a passive solar collector module for building facades comprising a transparent panel and a heat absorbing panel, separated from one another by an air chamber and assembled in a frame; an upper air conduit for communicating the air chamber with an area close to the ceiling of a story of a building; a lower air conduit for communicating the air chamber with an area close to the floor of a story of a building; an environmental air inlet in the lower part of the module and a heated air outlet and in the upper part of the module; a first air directing system operable such that in a first position it blocks the air outlet and in a second position it blocks the upper air conduit; a second air directing system operable such that in a first position it blocks the lower air conduit, in a second position it blocks the air flow towards the air outlet and in a third position it does not block either the lower air conduit or the air flow towards the air outlet.