Adaptation of single-family houses to the nZEB objective in cool-temperate climates of Spain. Optimisation of the energy demand and the thermal comfort by full-scale measurements and simulation assessments with an insight into the global warming scenarios

394 p.Se han analizado las características energéticas de las viviendas unifamiliares de consumo de energía casinulo (nZEB) construidas en España. La primera parte analiza los resultados de monitorizar durante 14meses el funcionamiento real de una vivienda pasiva en uso. El consumo de calefacción fue muy reducido,de 17,6 kWh/m². Se analizaron el confort térmico y el comportamiento de la envolvente térmica, midiendolas pérdidas de calor por la envolvente y la ventilación. Se analizó el confort térmico de la casa en veranocon diversos métodos y se comprobó que no existe sobrecalentamiento, gracias a la ventilación naturalempleada. La segunda parte compara los potenciales de mejora en invierno con cambios en la calefacción,y en verano mediante refrescamiento por ventilación y sombreamiento. Se calibró un modelo de simulacióndel rendimiento energético del edificio (BEPS) ajustado mediante los valores mensuales de la casamonitorizada. La ventilación mecánica con bypass de verano al caudal máximo es insuficiente para enfriarlo suficiente y mantener el confort térmico. Los sombreamientos ligeros exteriores para edificios existentestambién son insuficientes por sí solos. Es necesario aplicar ventilación natural para mantener los umbralesde confort interior. La tercera parte estudia la adaptación de las viviendas nZEB a los climas frescotempladosde España (se consideran las zonas C1, D1, D2, D3, E1 del CTE) a través de unos casosunifamiliares tipo. Se recomiendan niveles de aislamiento en la envolvente entre 10 cm y 20 cm según lazona climática, forma y orientación de cada caso. Se estudió la capacidad de adaptación con ventilación(VMC-RC y natural) y sombreamientos convencionales. Los resultados indican que es posible conseguirun confort térmico óptimo en verano e invierno aplicando las medidas adecuadas de refrescamiento pasivo,sin refrigeración activa en todas las zonas climáticas. Las simulaciones con climas futuros indican subidasde las temperaturas interiores entre 1-2 °C para 2040 y entre 2-5 °C para 2080. Se recomienda que losdiseños actuales verifiquen el sobrecalentamiento en los escenarios futuros, para mantener en el futuro elconfort térmico en las viviendas unifamiliares de las zonas climáticas estudiadas

Adaptation of single-family houses to the nZEB objective in cool-temperate climates of Spain. Optimisation of the energy demand and the thermal comfort by full-scale measurements and simulation assessments with an insight into the global warming scenarios

394 p.Se han analizado las características energéticas de las viviendas unifamiliares de consumo de energía casinulo (nZEB) construidas en España. La primera parte analiza los resultados de monitorizar durante 14meses el funcionamiento real de una vivienda pasiva en uso. El consumo de calefacción fue muy reducido,de 17,6 kWh/m². Se analizaron el confort térmico y el comportamiento de la envolvente térmica, midiendolas pérdidas de calor por la envolvente y la ventilación. Se analizó el confort térmico de la casa en veranocon diversos métodos y se comprobó que no existe sobrecalentamiento, gracias a la ventilación naturalempleada. La segunda parte compara los potenciales de mejora en invierno con cambios en la calefacción,y en verano mediante refrescamiento por ventilación y sombreamiento. Se calibró un modelo de simulacióndel rendimiento energético del edificio (BEPS) ajustado mediante los valores mensuales de la casamonitorizada. La ventilación mecánica con bypass de verano al caudal máximo es insuficiente para enfriarlo suficiente y mantener el confort térmico. Los sombreamientos ligeros exteriores para edificios existentestambién son insuficientes por sí solos. Es necesario aplicar ventilación natural para mantener los umbralesde confort interior. La tercera parte estudia la adaptación de las viviendas nZEB a los climas frescotempladosde España (se consideran las zonas C1, D1, D2, D3, E1 del CTE) a través de unos casosunifamiliares tipo. Se recomiendan niveles de aislamiento en la envolvente entre 10 cm y 20 cm según lazona climática, forma y orientación de cada caso. Se estudió la capacidad de adaptación con ventilación(VMC-RC y natural) y sombreamientos convencionales. Los resultados indican que es posible conseguirun confort térmico óptimo en verano e invierno aplicando las medidas adecuadas de refrescamiento pasivo,sin refrigeración activa en todas las zonas climáticas. Las simulaciones con climas futuros indican subidasde las temperaturas interiores entre 1-2 °C para 2040 y entre 2-5 °C para 2080. Se recomienda que losdiseños actuales verifiquen el sobrecalentamiento en los escenarios futuros, para mantener en el futuro elconfort térmico en las viviendas unifamiliares de las zonas climáticas estudiadas

Combination of Diagnostic Tools for the Proper Identification of Moisture Pathologies in Modern Residential Buildings

A study of moisture pathologies in a modern residential multifamily building is presented. The housing block was designed under the regulation NBE-CT of 1979 in northern Spain. After the appearance of some moisture problems in the façades, three complementary studies were conducted to analyze the situation of the envelope and diagnose the best improvement possibilities. First, indoor conditions of temperature and humidity of the apartments with moisture pathologies were monitored. During 40 winter days, the occupancy, heating operation, and natural ventilation were analyzed. Second, the inner and outer surface temperatures of the studied façades were measured. Thermal insulation degree, thermal capacity, and thermal bridge effects were measured to assess the risk of interstitial condensation under the real conditions of use. Third, an infrared thermographic survey was carried out, which allowed the detection of irregularities and the assessment of moisture problems. The wrong interpretations, which would have been made if the complementary studies had not been done, are exposed. The key towards the accurate diagnosis was the combination of tools. Finally, some technical solutions based on ventilation or thermal insulation enhancement are proposed as different ways to reduce the high levels of relative humidity indoors and minimize the risk of condensation in the futur

Airtightness Analysis of the Built Heritage–Field Measurements of Nineteenth Century Buildings through Blower Door Tests

Airtightness is a major issue in architectural design and it has a significant impact on the energy performance of buildings. Moreover, the energy behaviour of built heritage is due, to its singular characteristics, still a great unknown. The aim of this study is to establish a better knowledge of the airtightness of historical buildings, based on an in depth field study using blower-door tests. A set of 37 enclosures were analyzed inside eight buildings located in historical areas of a Spanish city with a significant built heritage. They were constructed between 1882 and 1919 and include diverse construction typologies applied for many building uses such as residential, cultural, educational, administrative and emblematic. The results indicate lower values compared to other previous airtightness studies of historical buildings. The average air change rate was found to be n50 = 9.03 h−1 and the airtightness of the enclosures presented a wide range of between 0.68 and 37.12 h−1. Three main levels of airtightness were identified with two thirds of the tested samples belonging to the intermediate level between 3–20 h−1. To conclude, several correlations have been developed which provide a method to estimate air leakage and could serve as a basis for energy performance studies of these kinds of building.This work has been funded through the Researcher Training Program of the Department of Education, Language Policy and Culture of the Basque Government (Spain) with the PhD fellowship PRE_2016_2_0178

Internet of things and open source platforms as support tools for construction 4.0.

Hoy en día, las ciudades están experimentando radicales cambios operacionales. Estos nuevos modelos conocidos como Smart Cities tienen como objetivo mejorar la calidad de vida de los ciudadanos mediante el uso de datos recopilados sobre el entorno a través del uso de Tecnologías de la Información y la Comunicación (TIC). Esta nueva situación permite a los ciudadanos interactuar más eficientemente con los nuevos elementos inteligentes que componen las ciudades, como las infraestructuras, las construcciones y los edificios. Además, el Internet of Things (IoT) es una de las grandes tecnologías que respalda a las Smart Cities para lograr estos objetivos. El IoT ha sido llamado como la próxima Revolución Industrial o la próxima evolución de Internet. Impactará la forma en que las empresas, los gobiernos y los consumidores interactúan con el mundo físico a través de sensores, cámaras, dispositivos de mano, teléfonos inteligentes y otros dispositivos inteligentes. A su vez, una de las líneas de investigación que está adquiriendo gran relevancia está relacionada con las tendencias de aplicación de software y hardware abiertos. Una de estas ramas son las bien conocidas Open Source Platforms (OSP), Plataformas de Código Abierto, que permite el desarrollo de proyectos de desarrollo propio (DIY). Gracias a ello, actualmente es posible llevar a cabo proyectos y soluciones que hasta ahora difícilmente eran posibles hacer realidad. El presente trabajo muestra una de las líneas de investigación que se está llevando a cabo desde el grupo en el ámbito de la monitorización y automatización de los edificios a través de la combinación de las OSP y el IoT. Además de mostrar las posibilidades de desarrollo existentes se presentará un caso práctico de esta tecnología que se llevó a cabo durante el proceso de monitorización energética en el edificio San Roke 32 de Donostia-San Sebastián rehabilitado bajo los criterios Passivhaus.Today, cities are experiencing radical operational changes. These new models known as Smart Cities aim to improve the quality of citizens life using data collected about the environment through the use of Information and Communication Technologies (ICT). In addition, the Internet of Things (IoT) is one of the great technologies that supports Smart Cities to achieve these objectives. At the same time, one of the research lines that is becoming very relevant is related to open software and hardware application trends. One of these branches are the well-known Open Source Platforms (OSP), which allows the development of self-developed projects (DIY).Thanks to this, it is now possible to carry out projects and solutions that until now were hardly possible to achieve. The present work shows one of the lines of research that is being carried out from the group in the field of monitoring and automation of buildings through the combination of the OSP and the IoT. In addition to showing the existing development possibilities, a practical case of this technology will be presented, which was carried out during the energy monitoring process in the San Roke 32 building in Donostia San Sebastián, rehabilitated under the Passivhaus criteria

A photovoltaic forced ventilated façade (PV-FVF) as heat source for a heat pump: Assessing its energetical profit in nZEB buildings

The European Union is changing its energy model towards a more efficient and sustainable one. In this new outlook, the Heat Pump (HP) has become a leading technology in the building energy sector. The use of the air source heat pump (ASHP) in the energy installations in the so-called nZEB low consumption buildings is currently on the increase. Furthermore, its performance improves when supported by solar energy, which can be achieved through the use of hybrid solar thermal photovoltaic elements (BIPV/T) integrated into the building’s façade, thus reducing consumption by 9 or 10%. However, the improvement can be even higher if a thermal storage system is incorporated. This research demonstrates the potential of one particular photovoltaic forced ventilated façade (PV-FVF) used as support for a heating and DHW system based on ASHPs, taking advantage of the entire building as a thermal accumulation system. For this, an “Adaptive Indoor Temperature Setpoint Strategy”, called Tadaptive, is proposed as one alternative mode of operation for the PV-FVF plus ASHP hybridisation. The objective is to transfer thermal energy to the building when the façade is obtaining a higher solar thermal gain. The PV-FVF was characterised experimentally in exterior conditions in a PASLINK test. It was modelled numerically and analysed on a whole building level using a thermal simulation programme into which the predictions of the numerical model were incorporated. Using as an example a residential building with underfloor heating in the city of Madrid, Spain, it was found that the use of the Tadaptive as the accumulation strategy could double the savings obtained with an ASHP supported by a PV-FVF, reducing heating consumption by 19.9%; while including the photovoltaic generation of the outer leaf reduces the total annual final energy for heat demand by 20.7%. The viability of this proposal is therefore demonstrated on the basis of existing technology as an alternative to reduce even further the energy consumption of nZEB type buildings for which the contribution of this hybridisation can be significant.This project has been made possible thanks to the agreement between the Basque Government and the University of the Basque Country UPV/EHU through of the ENEDI research group for the management and development of the Thermal Area of the Buildings Quality Control Laboratory of the Basque Government (AT-LCCE)

Ventilation of buildings with heat recovery systems: Thorough energy and exergy analysis for indoor thermal wellness

This work analyses deeply and critically the behavior of a heat recovery device of the ventilation system, in a dwelling of the Basque Country, under the energy and the exergy point of view. The aim is to show the different results that come from both perspectives. Heating period was monitored and data of the velocities and temperatures of the extracted and renovation airflows have been registered. With the data recorded, the effectiveness, energy efficiency and exergy efficiency of the recovery system have been calculated. Later, energy savings, primary energy savings and economic savings have been evaluated. Besides, the minimum difference between the outdoor and the indoor temperatures, from which the operation of the recovery system achieves a primary energy saving, an economic saving or an exergy saving were calculated. In addition to the exhaustive monitoring, the concentration of carbon dioxide in each room of the dwelling has been measured. The results obtained show the convenience of using ventilation systems with heat recovery from an energy point of view (with an energy efficiency of 89%), but not so if an exergy analysis is performed (with an exergy efficiency of 4%). After all, Second Law perspective penalizes a lot the electricity consumption for heating purposes, requiring a temperature differences (between the indoor and outdoor temperatures) higher than 32 °C in order to obtain exergy savings (not so under the energy perspective, where a difference of 1.6 °C is enough for having savings). The indoor air quality analysis confirms the adequacy in terms of CO2 concentration. This work is pioneer in terms of deep exergy application for ventilation systems.The authors acknowledge the support provided by the Laboratory for the Quality Control in Buildings of the Basque Government

A novel strategy to guarantee a minimum indoor temperature in social housing buildings

Energy poverty, along with climate change, is becoming one of the most worrying issues in Europe. Many people live without a minimum thermal comfort in their homes because they are not able to afford high energy bills. In other words, the indoor temperature of many dwellings remains below the recommended temperature during long periods, particularly in winter. This is more frequent among low-income families, which are over-represented in Spain’s social housing. In this paper, we present a simple and novel procedure to manage heating energy consumption in order to guarantee a minimum indoor temperature in social housing dwellings. To test the procedure, a social housing building located in the Basque Country, in northern Spain, has been selected as the case study. The heating consumption and outdoor temperature have been monitored for three winters and a characteristic curve for the heating consumption has been derived using the methodology proposed. Thanks to this procedure, the indoor conditions of the dwellings have improved by 80.9%, helping to alleviate energy poverty. The results show that the method is reliable, since the heating consumption needed to guarantee a specific indoor temperature could be estimated with an acceptable error rate. In the end, several aspects of this case study are discussed, and conclusions that propose certain suggestions to energy policies are derived.The authors would especially like to thank Alokabide S.A., the Social Housing institution of the Basque Government that manages public rental dwellings, specifically the technical team formed by Iñigo Aberasturi, Aitor Pradovaso and Carlos Orbea. The work has also been partially developed in the framework of the EnePoMAP Project, which has received funding from “la Caixa” Foundation under the project code LCF/PR/SR20/52550013. Finally, this work also received support from the Laboratory of Quality Control of Buildings of the Basque Government and the research group ENEDI from the University of the Basque Country UPV/EHU