100 research outputs found
Natural Materials - Materiality and construction of sustainable buildings - A one-to-one experience
Get PDFNatural materials are offered with a variety in almost every location. Using their potential in contemporary architecture diminishes the environmental impact of buildings. Distinct local architectural designs can be developed which are suited to the local building tradition and the local climate conditions.This brochure constitutes the practical outcome of an experimental construction process in the course, Materiality and Construction of Sustainable Buildings, which was conducted during the period March 12th – May 10th 2019.Contact: Prof. Dr. Runa T. Hellwig. CREATE. Dep. of Architecture Design and Media Technology, [email protected], +45 9940 362
Challenges and opportunities of Internet-of-Things in occupant-centric building operations: towards a life cycle assessment framework
Get PDFThe urgency to address the environmental impacts of the building sector, particularly emissions allocated to building operation, necessitates immediate, informed action. Occupant behaviour is a known driver of building operational emissions. Use of Internet-of-Things (IoT) devices holds great potential in mitigating and distributing occupancy-driven energy demand, ultimately aiming for net-zero emissions. However, a full accounting of the environmental impacts and advantages is still lacking. As the adoption of IoT scales up, what will be the environmental impact of the tools used, from sensor life cycle to data storage? This study reviews the interdisciplinary literature on life cycle assessment (LCA) of IoT in buildings, encompassing emissions from pre-deployment to end-of-life, as well as savings from reduced building operational emissions. This opens a vital discourse on the opportunities and challenges of building-related IoT
On the relation of thermal comfort practice and the energy performance gap
Get PDFRecent research results from different countries show that although energy efficiency measures in buildings indeed led to lower energy use in buildings, there is a performance gap between the calculated energy use and the actual measured energy use in energy-efficient houses, leading to a higher energy use than predicted. Thermal comfort related behaviour is one out of manifold reasons contributing to this performance gap. Thermal comfort requirements are based on objectively measurable parameters. A number of contextual factors impact an individual's thermal comfort perception and preference. Technological opportunities and material arrangements offer several ways to conditioning indoor environments. Research shows that they shape the occupants' thermal comfort attitudes. Over time, technology as conditioning practice and insulation has led to different thermal comfort practice in buildings contributing to this performance gap. As humans show an excellent adaptation potential towards a wide range of temperature, enabling them to adapt to diverse climates but also seasonally, it follows also the adaptation process can work in the opposite direction. Hence, that with reduced exposure to outdoor weather and more narrow temperature ranges inside building humans might also adapt to indoor thermal conditions and get more sensitive to small indoor temperature changes, leading probably to higher indoor temperature over time ("indoor exposure rebound"). As our energy conservation efforts of the recent years show less effects than expected, it seems that the two mainly applied sustainability strategies efficiency and consistency have limited effects as they are affected by rebound phenomena. Sufficiency, as the third sustainability strategy, is not yet a generally accepted strategy. It refers to what has been described as "the right measure". The question of what would be "the right measure" of indoor thermal comfort, meaning what thermal conditions would be sufficient, can be raised. Based on a discussion of findings from literature, it will be concluded that there is a need for a new thermal comfort thinking in climates which have the need for seasonal or all year round active conditioning leading to a more sufficient conditioning practice
Natürlich behaglich. Natürliche Lüftung und Behaglichkeit – Gegensätze?:(Naturally comfortable. Natural ventilation and comfort - opposites?)
Get PDFInnentemperaturtrends und die unbeabsichtigten Wechselwirkungen
Get PDFThis article was developed based on a keynote talk at the Building Physics Days in Weimar 2024.Abstract EnglishIn recent years, it is noticeable that indoor temperatures in residential buildings have followed three trends: decreasing spatial variation, decreasing temporal variation and simultaneously increasing mean levels of indoor temperature. At the same time, architectural design and the construction technologies applied in new buildings and building renovation have undergone a change. In addition, what is considered an appropriate indoor temperature level has changed over time. This is reflected both in quotes from the technical literature and in the requirements set in standards. Research suggests that such changing indoor temperature patterns are associated with unintended interactions in the following main areas: human health and resilience, human indoor climate perception, environmental impacts of buildings, and resilience of buildings in a changing climate. Possible explanations lie in considering the interplay of techno-cultural factors, techno-physical building factors, occupant behavioural factors, physiological adaptation factors and psychological factors, rather than considering any one of these factors individually. This leads to the question of whether the established ways of thinking in building planning and operation should remain unchanged in the future. The article concludes with suggestions for adapting these approaches to support such a discussion.Abstract GermanDieser Artikel wurde aus einem Keynotevortrag auf den Bauphysiktagen in Weimar 2024 entwickelt.KurzfassungIn den letzten Jahren ist es auffallend, dass die Innentemperaturen in Wohngebäuden drei Trends folgen: abnehmende räumliche Variation, abnehmende zeitliche Variation und gleichzeitig steigende mittlere Innentemperaturen. Architektonische Gestaltung und die in Neubauten und bei der Gebäudesanierung angewandten Bautechnologien haben sich seit den 70er Jahren stark verändert. Darüber hinaus hat sich das, was als angemessenes Innentemperaturniveau angesehen wird, im Laufe der Zeit verändert. Dies spiegelt sich sowohl in Zitaten aus der Fachliteratur als auch in den Anforderungen der Normen wider. Forschungsarbeiten legen nahe, dass solche veränderten Innentemperaturmuster mit unbeabsichtigten Wechselwirkungen in folgenden Hauptbereichen assoziiert sind: menschliche Gesundheit und Resilienz, menschliche Raumklimawahrnehmung, Umweltauswirkungen von Gebäuden sowie Resilienz von Gebäuden in einem sich verändernden Klima. Mögliche Erklärungsansätze liegen in der Betrachtung des Zusammenspiels von techno-kulturellen Faktoren, techno-bauphysikalischen Faktoren, verhaltensbezogenen Faktoren der Bewohner, physiologischen Anpassungsfaktoren und psychologischen Faktoren und nicht in der Betrachtung eines einzelnen dieser Faktoren. Dies führt zu der Frage, ob die etablierten Denkweisen in Gebäudeplanung und -betriebs in der Zukunft unverändert gelten sollen. Der Beitrag schließt mit Vorschläge für die Anpassung dieser Denkansätze, die eine solche Diskussion unterstützen sollen.This article was developed based on a keynote talk at the Building Physics Days in Weimar 2024.Abstract EnglishIn recent years, it is noticeable that indoor temperatures in residential buildings have followed three trends: decreasing spatial variation, decreasing temporal variation and simultaneously increasing mean levels of indoor temperature. At the same time, architectural design and the construction technologies applied in new buildings and building renovation have undergone a change. In addition, what is considered an appropriate indoor temperature level has changed over time. This is reflected both in quotes from the technical literature and in the requirements set in standards. Research suggests that such changing indoor temperature patterns are associated with unintended interactions in the following main areas: human health and resilience, human indoor climate perception, environmental impacts of buildings, and resilience of buildings in a changing climate. Possible explanations lie in considering the interplay of techno-cultural factors, techno-physical building factors, occupant behavioural factors, physiological adaptation factors and psychological factors, rather than considering any one of these factors individually. This leads to the question of whether the established ways of thinking in building planning and operation should remain unchanged in the future. The article concludes with suggestions for adapting these approaches to support such a discussion.Abstract GermanDieser Artikel wurde aus einem Keynotevortrag auf den Bauphysiktagen in Weimar 2024 entwickelt.KurzfassungIn den letzten Jahren ist es auffallend, dass die Innentemperaturen in Wohngebäuden drei Trends folgen: abnehmende räumliche Variation, abnehmende zeitliche Variation und gleichzeitig steigende mittlere Innentemperaturen. Architektonische Gestaltung und die in Neubauten und bei der Gebäudesanierung angewandten Bautechnologien haben sich seit den 70er Jahren stark verändert. Darüber hinaus hat sich das, was als angemessenes Innentemperaturniveau angesehen wird, im Laufe der Zeit verändert. Dies spiegelt sich sowohl in Zitaten aus der Fachliteratur als auch in den Anforderungen der Normen wider. Forschungsarbeiten legen nahe, dass solche veränderten Innentemperaturmuster mit unbeabsichtigten Wechselwirkungen in folgenden Hauptbereichen assoziiert sind: menschliche Gesundheit und Resilienz, menschliche Raumklimawahrnehmung, Umweltauswirkungen von Gebäuden sowie Resilienz von Gebäuden in einem sich verändernden Klima. Mögliche Erklärungsansätze liegen in der Betrachtung des Zusammenspiels von techno-kulturellen Faktoren, techno-bauphysikalischen Faktoren, verhaltensbezogenen Faktoren der Bewohner, physiologischen Anpassungsfaktoren und psychologischen Faktoren und nicht in der Betrachtung eines einzelnen dieser Faktoren. Dies führt zu der Frage, ob die etablierten Denkweisen in Gebäudeplanung und -betriebs in der Zukunft unverändert gelten sollen. Der Beitrag schließt mit Vorschläge für die Anpassung dieser Denkansätze, die eine solche Diskussion unterstützen sollen.<br/
KAPITEL 1.2 Raumklimatische Grundlagen (Chapter 1.2 Foundations of Indoor Climate)
No full textThis periodical is the classic compendium for german engineers in heating, ventilation and air-conditioning planning. It was established by Hermann recknagel 1896. 124 years after the first edition was published, now in 2020, the 80 edition is published. The compendium is aperiodical which is updated every second year.The contribution by Hellwig, Scherer, Bischof and Wiesmueller is the chapter on basic knowledge on indoor climate perception and requirements, which form the basis for every conditioning system of the indoor environment and hence determining - beside the building envelope - how energy efficient a building can be operated. <br/
KAPITEL 1.2 Raumklimatische Grundlagen (Chapter 1.2 Foundations of Indoor Climate)
No full textThis periodical is the classic compendium for German engineers in heating, ventilation and air-conditioning planning. It was established by Hermann Recknagel 1896. Now in 2024, the 82nd edition is published. The compendium is a periodical which is updated every second year.The contribution by Hellwig, Scherer, Bischof and Wiesmueller is the chapter on basic knowledge on indoor climate perception and requirements, which forms the basis for every conditioning system of the indoor environment and hence determining - beside the building envelope - how energy efficient a building can be operated
The colours of comfort : From thermal sensation to person-centric thermal zones for adaptive building strategies
Get PDFThermal comfort research has been traditionally based on cross-sectional studies and spatial aggregation of individual surveys at building level. This research design is susceptible to compositional effects and may lead to error in identifying predictors to thermal comfort indices, in particular in relation to adaptive mechanisms. A relationship between comfort and different predictors can be true at an individual level but not evident at the building level. In addition, cross-sectional studies overlook temporal changes in individual thermal perception due to contextual factors. To address these limitations, this study applied a longitudinal research design over 8 to 21 months in eight buildings located in six countries around the world. The dataset comprises of 5,567 individual thermal comfort surveys from 258 participants. The analysis aggregated survey responses at participant level and clustered participants according to their thermal sensation votes (TSV). Four TSV clusters were introduced, representing four different thermal sensation traits. Further analysis reviewed the probability of cluster membership in relation to demographic characteristics and behavioural adaptation. Finally, the analysis at individual level enabled the introduction of a new metric, the thermal zone (Zt), which in this study ranges from 21.5°C to 26.6°C. The thermal sensation traits and person-centric thermal zone (Zt) are a first step into the development of new metrics incorporating individual perceived comfort into dynamic building controls for adaptive buildings
Guidelines for low energy building design based on the adaptive thermal comfort concept - Technical report:IEA EBC Annex 69: Strategy and Practice of Adaptive Thermal Comfort in Low Energy Buildings.
Get PDFThe adaptive thermal comfort concept has been developed over many years and proven in numerous field studies (e.g. Webb 1964, Nicol and Humphreys 1973, Auliciems 1981b, de Dear et al. 1997, McCartney and Nicol 2002, Manu et al. 2016), showing that people are satisfied with a wide range of thermal conditions. Prerequisite is that people are provided with means to make themselves comfortable, that they know which opportunities they have, that it is socially acceptable to use these opportunities and that they are willing to use them (Hellwig, 2015). However, the overall understanding of how to design for such opportunities enabling the occupant to make themselves comfortable in relation to climate and building type, thus how to convert the adaptive thermal comfort concept into building design and concepts for operating buildings, is still limited. There are still common misunderstandings in the interpretation of the adaptive comfort approach among building planners and operators e.g. regarding the amount of control, the seriousness of this topic or the level of information needed by occupants for which reason guidance (e.g. CIBSE 2010, Cook et al. 2020) and knowledge transfer (e.g. Hellwig and Boerstra 2017, 2018) is absolutely essential. Consequently, there is still a gap between scientific research and real-world-application, which this report aims to diminish.In line with the activities within IEA EBC Annex 69 Subtasks A, B, and C, the present report includes four main sections, addressing the above listed identified challenges and barriers to the adoption of the adaptive thermal comfort in practice by explaining the adaptive thermal comfort principles, by illustrating the benefits from applying the adaptive principles in buildings, through guidance on how to implement the adaptive principles in the design and operation of buildings, especially providing guidance on how to design for adaptive opportunities. The Appendices contain additional information on standards, checklists for stakeholders in the design and operation of buildings as well as documentation and lessons learnt from the buildings investigated within this Annex 69 Subtask C. This report is formulated with the help of frameworks (Hellwig et al. 2019, Hellwig et al. 2020) developed to facilitate the adoption of adaptive principles in the design and operation of buildings. We aim to provide the knowledge on a general level of understanding, so that it is possible to apply the knowledge in different types of building usage, different climate zones and occupant groups. However, the majority of examples used in this report stems from office buildings, which is mainly rooted in the fact that the majority of research studies focussed on this type of building. Nevertheless, we have supplemented this report with examples from other building types. The target group of the guidelines in this report are building planners (architects, engineers, sustainability certification consultants/councils) and building operators (facility managers, operators, owners, and tenants). Furthermore, the guidelines in this report are intended as critical sources and guidance to educate future building professionals and stakeholders.The report includes four main sections, as outlined below.Section 2 summarises the three adaptive comfort principles, i.e. physiological, behavioural and psychological adaptation. The section follows with a discussion on the effectiveness of the adaptive principles and on the order of activation of adaptive responses. It ends with a brief account on the development of adaptive models.Section 3 describes the benefits from applying the adaptive principles in buildings, including energy savings, resilience to climate change, improved usability and thermal satisfaction, as well as improved health and well-being.Section 4 presents the developed framework for adopting the adaptive comfort principles in design and operation of buildings. The main elements of the framework are described, i.e. the building context, adaptive responses and actions, the building planning and design, –the adaptive opportunities design, and the operational planning and operation. Each of these subsections includes guidelines to facilitate the integration of adaptive principles. Section 4 ends with considerations and recommendations for adopting adaptive comfort in conditioned buildings, including advice for facilitating free-running mode in building operation as often as possible and ways to integrate the use of the adaptive principles in permanently or long-season conditioned spaces.AppendicesAppendix 1 summarises information on adaptive models used in international and national standards, as well as examples of models developed by research in various locations and climates.Appendix 2 provides checklists of parameters that can help stakeholders implement measures to ensure the availability of adaptive opportunities in buildings.Appendix 3 is a collation of case studies with practical learnings from adaptive buildings investigated in Annex 69 Subtask C.Appendix 4 lists publications, presentations and workshops related to Activity B2 of IEA EBC Annex 69.Authors of main report on guidelines, Appendix 1, 2, 4 worked out in Subtask B, Activity B2Lead: Runa T. Hellwig, Aalborg University, DenmarkCo-lead: Despoina Teli, Chalmers University, SwedenContributors:Marcel Schweiker, Karlsruhe Institute of Technology, GermanyRodrigo Mora, British Columbia Institute of Technology, CanadaJoon-Ho Choi, University of Southern California, USARajan Rawal, CEPT University, IndiaM.C.Jeffrey Lee National Taichung University of Science and Technology, TaiwanWang Zhaojun, Harbin Institute of Technology, ChinaFarah Al-Atrash, German Jordanian University, JordanAuthors of Appendix 3 Documentation of buildings investigated in Annex 69, Subtask CLead: Richard de Dear, University of Sydney, AustraliaCo-Lead: Stephanie Gauthier, University of Southampton, UK; Jungsoo Kim, University of Sydney, AustraliaContributors (in alphabetical order): Farah Al-Atrash, German Jordanian University, JordanLeonidas Bourikas, University of Southampton, UK Bin Cao, Tsinghua University, ChinaJoon-Ho Choi, University of Southern California, USAChungyoon Chun, Yonsei University, KoreaHeidi Creighton, Buro Happold Engineering, USAPaul Cooper, University of Wollongong, AustraliaJérôme Damiens, Tsinghua University, ChinaRichard de Dear, University of Sydney, AustraliaStephanie Gauthier, University of Southampton, UKRuna T. Hellwig, Aalborg University, DenmarkWenjie Ji, Tsinghua University, ChinaXinyu Jia, Tsinghua University, ChinaJungsoo Kim, University of Sydney, AustraliaSuhyun Kwon, Yonsei University, KoreaKyeongsuk Lee, University of Southern California, USA<br/
The ambivalence of personal control over indoor climate - how much personal control is adequate?
Get PDFLiterature sets personal control over indoor environmental conditions in relation to the gap between predicted and actual energy use, the gap between predicted and observed user satisfaction, and health aspects. A focus on building energy performance often leads to the proposal of more automated and less occupant control of the indoor environment. However, a high degree of personal control is desirable because research shows that a low degree (or no) personal control highly correlates with indoor environmental dissatisfaction and sick building syndrome symptoms. These two tendencies seem contradictory and optimisation almost impossible. Based on current efficiency classes describing the effect of room automation systems on building energy use during operation, fundamental thoughts related to thermophysiology and control, recent laboratory experiments, important lessons learnt from post-occupancy studies, and documented conceptual frameworks on the level of control perceived, we discuss the ambivalence of personal control and how much personal control is adequate. Often-proposed solutions ranging from fully automated controls, over manual controls to dummy controls are discussed according to their effect on a) building energy use during operation and b) occupants perceived control. The discussion points to the importance of adequate personal control. In order to meet the goals for nearly zero energy buildings and for a human-centric design, there is the need to establish design procedures for adequate personal control as part of the design process
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