Abstract - An energy auditing tool (PHPP) was evaluated against a dynamic simulation tool (TRNSYS) and used for the assessment of energy conservation measures in a demo case study. The comprehensive comparison of useful heating and cooling demands and loads included three building types (single-, multi-family house, and office), three building energy levels (before renovation and after renovation with a heating demand of 45 and 25 kWh/(m²a)) and seven European climates. Dynamic simulation results proved PHPP (monthly energy balance) to be able to calculate heating demand and energy savings with good precision and cooling demand with acceptable precision compared to detailed numerical models (TRNSYS). The average deviation between the tools was 8% for heating and 15% for cooling (considering climates with a relevant cooling load only). The higher the thermal envelope quality was, i.e. in case of good energy standards and in cold climates, the better was the agreement. Furthermore, it was confirmed that PHPP slightly overestimates the heating and cooling loads by intention for system design. (...)

Abstract - One of the promising use cases of building performance simulation (BPS) is its role as a virtual laboratory in research and development (R&D) projects that aim to bring innovative building components from initial idea towards market introduction. By facilitating what-if explorations and whole-building insights, BPS can create complementary value, alongside actual experiments. However, explorative R&D projects tend to be rather erratic and are more ill-defined than typical BPS tasks. This raises several issues concerning application, interpretation and communication of BPS-based performance predictions in explorative contexts. The aim of this paper is to highlight opportunities and potential pitfalls of the use of BPS in this application domain (...).

Abstract - During the last decades, a great number of innovative building envelope materials and façade components have been developed. The majority of these technologies promise significant improvements in energy efficiency and occupant's comfort, with products that are easily available in the market. However, it remains a challenge to assess the performance of such facades, leading to difficulties for efficient design, operation, and maintenance. As a consequence, the market adoption of adaptive facades is not realizing its full potential, resulting in missed opportunities for energy savings and improved occupant satisfaction. In this study, the current trends of adaptive facades are investigated, with particular emphasis on their performance assessment (...) Download open access paper

Abstract - Traditional façade characterisation metrics such as U-value and g-value are of limited value in the design process of buildings with adaptive façades. This issue is particularly important for adaptive façade components that have the capability of controlling thermal energy storage in the construction thermal mass. Building performance simulations can help to analyse the performance of buildings with adaptive façades, but such studies usually only provide information about the energy and comfort performance at room level. (...) This paper presents experiences and lessons learned from four European R&D projects that have introduced novel metrics to capture the dynamic performance of adaptive opaque façades. 

Abstract - Advanced glazing systems with special spectral characteristics or light redirecting behavior are commonly applied to improve building energy efficiency and indoor comfort conditions. The angle-dependent optical properties of such advanced windows can be markedly different from those of ordinary glass. To achieve accurate building performance predictions, it is necessary to represent the physical behavior of advanced window systems at a sufficiently high level of detail in building simulation programs [...]  Download open access paper

Abstract - In this paper the performance of a novel type of closed-loop forced convective dynamic insulation system is investigated. First results show that a ninefold higher U-value can be achieved in comparison with the insulating state of the system. Multiple case studies have been analysed to study the behaviour and performance of the system. We found that the dynamic insulation system can reduce the energy consumption and increase the indoor thermal comfort of a typical residential building, while using less auxiliary energy than comparable passive cooling systems, such as night ventilation. Applying dynamic insulation to a façade construction with a heavyweight interior partition and lightweight exterior partition resulted in the best performance [...]  Download open access publication

Abstract - This article presents an overview of possibilities and points of attention for modelling the performance of dynamic CFS in building performance simulation software. Following a detailed analysis of the unique requirements that are associated with modelling of CFS, a comparative study of the capabilities in different software implementations is presented. In addition, we present on overview of state-of-the-art approaches to obtain the necessary Bi-directional Scattering Distribution Functions (BSDF), involving experimental characterisation, databases, and component-level ray-tracing approaches. The second part of the paper provides a detailed discussion of a case study of a high reflective lamella system [...]

Abstract - In this paper, the energy performance of a solar thermal (ST) façade system is studied in relation to its connection to a district heating system. This concept allows for the direct use of ST heat in the building, while taking profit from the network for delivery/selling of excess heat and purchase of heat during periods of underproduction. The use of unglazed collectors for low-intrusive architectural interaction in façades is discussed. Studies are carried out on the heat production of the system and its capacity to cope with local demands. Economic studies are carried out in order to balance the investment and operational costs/profits of the system. Download open access publication

Abstract - The scope of this paper is to highlight the main barriers that are experienced in the development of façade-integrated solar water storage. This activity is a part of the SunRise project that aims to develop a new unitised curtain wall element for tertiary office buildings. The façade element integrates a complete solar thermal system consisting of a solar collector, hot water storage, a radiant panel, and all the required operation components. A mock-up of the solar façade is manufactured to identify practical constructional issues. The thermal behaviour of the tank is analysed through FEM simulations and laboratory tests. Download publication

Abstract - In 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. Download open access publication

Abstract - The paper presents results from three ongoing projects. BATISOL and BASSE investigate the development of solar thermal technology so as to fulfil the functional, constructional and formal requirements of building skins. Façade assemblies are turned into active skins by integrating unglazed solar collectors in the place of conventional renders and claddings. RETROKIT explores the usage of renewable energy gains within an alternative environmental control strategy, by direct supply of heated air into the ventilation system. Finally, a discussion is presented on architectural, constructional and thermal performance aspects of these solutions, based on both design assessments and experimental data. Download open access publication

Abstract - The main contribution of this review article is to bring together and analyse the existing information on building performance simulation of adaptive facades. In the first part, the unique requirements for successful modelling and simulation of adaptive facades are discussed. In the second part, the capabilities of five widely used BPS  tools are reviewed, in terms of their ability to model energy and occupant comfort performance of adaptive facades. Finally, it discusses various ongoing trends and research needs in this field.

Abstract  -  DALEC is a novel, combined lighting and thermal simulation web tool. This tool allows building designers to evaluate their individual façade concepts in terms of thermal and visual performance and ultimately their impact on overall building energy use. Although easy to use, the software accounts for the complex thermal and light processes in buildings, by way of sophisticated and time-saving pre-calculations. Based on climatic data a calculation of heating, cooling and electric lighting loads can be obtained within a simulation time shorter than one second. The model has been validated by comparison with experimental data and other state-of-the-art software and shows deviations less than 15%. Not only energy demand is considered, but also user behaviour (e.g. glare protection), as well as visual and thermal comfort. This innovative, holistic approach facilitates and accelerates the design of sustainable and energy-efficient building for new, as well as for refurbished buildings.

Abstract - Due to steadily increasing use of technologies for the reduction of the non-renewable energy needs in buildings (...)  deeper architectural integration is needed, also considering on cost and assembly process optimization to ensure wide market adoption. In this context, two main trends appear: Integration and hybridation of solar systems in building envelopes. Integrated solutions are created when modular and dimensionally variable glazed collectors are integrated in curtain wall structures or in external cladding systems. Hybrid solutions such as external thermal insulation systems and sandwich panels are generated where unglazed collectors are integrated as part of renders, claddings, etc. to obtain neutral aesthetical impact. Architectural, constructional and thermal results are discussed, not only based on design assessments, but also on manufacture, assembly and assessment results from experimental data.
 

Abstract - The layout of an air based solar cooling system integrated into a façade module was designed and assessed. This solution utilizes a triple state absorption module within a Sydney type vacuum tube solar collector to thermally condition an airflow directed to the internal space reducing the thermal load covered by traditional technologies (...). The results show that a combination of active and passive cooling can greatly limit the use of cooling coil even though the performance varies significantly with climate and façade orientation. On the contrary, the performance in heating have been found quite poor for all configurations studied. Abstract