Building Geometry as a Variable in Energy, Comfort, and Environmental Design Optimization—A Review from the Perspective of Architects

Due to negative environmental impacts caused by the building industry, sustainable buildings have recently become one of the most investigated fields in research. As the design technique itself is mainly responsible for building performance, building energy design optimization is of particular interest. Several studies concentrate on systems, operation, and control optimization, complemented by passive strategies, specifically related to the envelope. In building physics, different architectural considerations, in particular, the building’s shape, are essential variables, as they greatly influence the performance of a building. Most scientific work that takes into consideration building geometry explores spaces without any energy optimization or calculates optimization processes of a few basic variables of simplified space geometries. Review studies mainly discuss the historic development of optimization algorithms, building domains, and the algorithm-system and software framework performance with coupling issues. By providing a systemized clustering of different levels of shape integration intensities, space creation principals, and algorithms, this review explores the current status of sustainability related shape optimization. The review proves that geometry design variable modifications and, specifically, shape generation techniques offer promising optimization potential; however, the findings also indicate that building shape optimization is still in its infancy.

In Memory of George A. Martynov

Provided information about the deceased Georgy Aleksandrovich Martynov - Doctor of Physical and Mathematical Sciences, Professor, Chief Researcher of the Laboratory of Surface Forces of the A.N. Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, a prominent specialist in the field of the theory of liquid state and surface phenomena: basic biographical data, training at the Faculty of Physics of Lomonosov Moscow State University, work at the Institute of Building Physics, defense of candidate (technical) and doctoral (physical and mathematical) dissertations, authorship of more than two hundred scientific papers, three monographs, membership in academic councils, participation and organization of Russian and international conferences and seminars, editorial staff in scientific journals, leadership of doctoral and master's theses.

Hygrothermal simulations of timber-framed walls with air leakages

Air leakages can create substantial excess moisture loads into envelope structures and degrade their hygrothermal performance. Multiple previous research projects have studied the behaviour and modelling of air leakages in building physics applications, but it is still quite rare to see air leakages being considered in practical building design simulations. The purpose of this paper is to present the selection of input parameters for air leakage simulations, utilisation of a factorial design to manage simulation cases and the results for a timber-frame wall with and without air leakages. According to the results, the air permeability of mineral wool and the air pressure difference over the envelope were the two most important factors for the dry air mass flow through the structure, as opposed to gap width and leakage route. An ideally airtight structure had a better hygrothermal performance compared to leaky structure. However, when leakages were present, the exact yearly average air flow rate in the range 70…420 dm3/(m2h) did not have a strong correlation to the performance indicators. For the other studied variables, the existence of a 50 mm thick mineral wool insulation on the exterior side of the gypsum board wind barrier and the impacts from climate change had the biggest effect on the moisture performance of the structure.

The ZEB Laboratory: the development of a research tool for future climate adapted zero emission buildings

The building sector is responsible for approximately 40 % of the energy consumption and carbon emissions worldwide. Buildings of the future will have to comply not only with stricter energy regulations, but they will also have to face changing climate challenges. To increase the level of interdisciplinary knowledge and to develop and test innovative technology with users, new types of adaptive research facilities are needed. The development of the ZEB Laboratory replies to this need. Developing the building as a research tool has made us focus on 1) a flexible laboratory for tomorrow building design research and 2) making the building itself a climate adapted zero emission building. The laboratory building is realised following the Norwegian ZEB-COM ambition. The development of this research tool has called for an iterative approach with use of partnering and collaborative elements for planning and production. Connected challenges related to e.g. research facility needs, building process, building physics, flexibility of use, energy supply and indoor environment had to be solved through iterations and co-creation processes. This paper presents a modern research tool for climate adaptation and mitigation measures for buildings including stormwater management at site and assesses the development and building process of the laboratory.

Preface for the Proceedings of the 8th International Building Physics Conference

Menghao Qin1 and Carsten Rode1 1Department of Civil Engineering, Technical University of Denmark, Lyngby, 2800, Denmark Emails: [email protected] [email protected] The 8th International Building Physics Conference (IBPC 2021) took place online during August 25-27, 2021. IBPC 2021 was organized by the Technical University of Denmark in cooperation with Aalborg University, Aarhus University, University of Southern Denmark, and Lund University. More than 370 participants from 37 countries worldwide attended the conference. IBPC 2021 is the eighth edition of the official triennial conference of the International Association of Building Physics (IABP). The IBPC 2021 unites researchers, practitioners, educators, and students from the construction sector worldwide. We meet to exchange new research and innovative technologies and to discuss current and future challenges and sustainable solutions within building physics. This year, IBPC was held as a virtual meeting due to the impact of COVID-19 and the limitations on the entry and exit. IBPC 2021 used PheedLoop and Zoom as the platform holding the online conference. There were 170 oral presentations and 100 poster presentations were arranged during the three-day conference. Every presentation was about 15 minutes, including 3 minutes for the Q&A part. Authors made their presentations on the topics covering all aspects of building physics. Though the authors and speakers couldn’t communicate face to face, the passion for involvement wasn’t affected. Papers have been gathered through a call issued in August 2020. We received around 420 submissions from 45 countries. We employed a single-blind peer-review process involving scholars of various fields related to Building Physics as reviewers. At the end of the reviewing process, 248 papers were accepted for the conference proceedings - Journal of Physics: Conference Series. Here we would like to thank all the scientific committee members who made great efforts on paper reviewing. The appreciation also goes to other organizing committee members, program chairs, keynote/invited speakers, session chairs and all the authors. Thanks for their understanding and support in this special time. We hope all the participants had a wonderful time during the conference and got fruitful inspiration from the presentations delivered by speakers and authors. Given the high-quality works done by authors, reviewers, and other committee members, we are confident that the IBPC 2021 proceedings capture the current state of the research in the related fields and hope it will motivate some of you in the longer term. We are looking forward to seeing you again in IBPC 2024. List of titles Chairs, Organizing committee, Scientific committee are available in this Pdf.

A review on coupled building physics analyses

This paper reviews methods and tools for coupled building physics analyses in the context of Building Performance Simulations (BPS) with a focus on Building Energy Simulations (BES) and Computational Fluid Dynamics (CFD) as a common application. Furthermore, requirements regarding the necessary information for simulations, data models and coupling are identified. Possibilities of automated simulation model generation, data exchange and the performance of existing multi physics simulation models are analysed and limiting factors are discussed.

Modelling climate related performances of building wall coatings and understanding the portability of the “Künzel” rule in different climates

How may a coating affect the hygrothermal performance of the building envelope in different climates? Years ago, Helmut Künzel, one of the fathers of Building Physics, proposed, a simple, well-known rule, relating two characteristics of a coating: its water absorption coefficient and its vapour diffusion. The “Künzel rule” (and the associated diagram), based on a model confirmed by field tests in the German climate, set an upper limit to both parameters and their product, became a German standard and a practice among experts, practitioners and manufacturers, in many European countries. This paper proposes the results of an analysis aiming to verify its portability in other climates and is based on an extensive simulation of the hygrothermal performances of a reference wall in six different climatic conditions.

Moisture-induced deformations of wood and shape memory

Wood is known to swell substantially during moisture adsorption and shrink during desorption. These deformations may lead to wood damage in the form of cracking and disjoining of wooden components in e.g. floor or windows. Two swelling mechanisms may be distinguished: reversible swelling/shrinkage and moisture-induced shape memory effect. In the latter, wood is deformed in the wet state and afterward dried under maintained deformation, in order that wood retains its deformed shape even after the removal of the mechanical loading, called fixation. When wood is wetted again, it loses its fixation, partially regains its original shape, called recovery. These two mechanisms have their origin at the nanoscale and are modelled here using atomistic simulation and after upscaled to continuum level allowing finite element modelling. Hysteretic sorption and swelling are explained at nanoscale by the opening and closing of sorption sites in ad-and desorption, where in desorption water molecules preferentially remained bonded at sorption sites. The moisture-induced shape memory is explained by the moisture-induced activation of the interfaces between the reinforcing crystalline cellulose fibres and its matrix at nanoscale, referred to as a molecular switch. Our work aims to highlight that the understanding of sorption-induced reversible deformation and moisture-induced shape memory may play an important role in wood engineering and in building physics applications.

Digital Twins of Building Physics Experimental Laboratory Setups for Effective E-learning

Hands-on experiments in laboratories are fundamental educational tools for technical sciences. However, laboratories are expensive and not always accessible to students: lockdown and in-person meeting restrictions due to the ongoing Covid-19 pandemic, distant location of teachers and students, facilities used for higher-priority purposes. Moreover, creating specific experimental setups for teaching only can be costly. In that context, digitalizing laboratory setups provides an attractive teaching alternative for remote e-learning. Digital twins are not meant to replace real-world experiments but should enable flexible teaching and effective learning at a lower cost. They complement physical setups and can be virtual extensions, allowing for larger and more complex study cases. e-learning is now popular and many educational institutions provide open-access videos of entire courses. However, the digitalization of practical exercises for engineering is yet limited. The e-learning effort presented in this paper aims to establish a series of digital twins of experimental setups for teaching building physics, energy in buildings and indoor environment. The development of the two first digital twins is detailed here. They are designed for teaching operation and balancing hydronic heating systems. Their numerical models and graphical user interfaces are created with the LabVIEW programming environment.