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This paper reports on the research-driven design process of an innovative thermal mass concept: Convective Concrete. The goal is to improve building energy efficiency and comfort levels by addressing some of the shortcomings of conventional building slabs with high thermal storage capacity. Such heavyweight constructions tend to have a slow response time and do not make effective use of the available thermal mass. Convective Concrete explores new ways of making more intelligent use of thermal mass in buildings. To accomplish this on-demand charging of thermal mass, a network of ducts and fans is embedded in the concrete wall element. This is done by developing customized formwork elements in combination with advanced concrete mixtures. To achieve an efficient airflow rate, the embedded lost formwork and the concrete itself function like a lung. The convection takes place with separate pipes on both sides of the concrete���s core to increase the charge/discharge of the thermal storage process. The first stage of the research, described in this paper, is to simulate the Convective Concrete at the component level, whereupon a mock-up is tested in a climate test set-up. The paper concludes with describing planned activities for turning this concept into a real building product., Journal of Facade Design and Engineering, Vol. 5 No. 1 (2017): Special Issue Powerskin

This chapter discusses the simulation of urban thermal microclimate with a focus on heat waves in urban areas, the simulation of overheating of buildings and the effects of adaptation measures to limit temperatures in buildings and urban areas during heat waves. The spatial scales are the meteorological microscale (neighborhood scale) and the building scale; the methods are computational fluid dynamics and building energy simulation. Adaptation measures investigated at the neighborhood scale are avenue trees, green facades and green roofs; adaptation measures at the building scale are increased thermal resistance, increased thermal mass, increased short-wave reflectivity of facades and roofs, peak ventilation, vegetated roofs and exterior solar shading.

A full-size (1 × 5 m2) luminescent solar concentrator (LSC) has been constructed and the edge electric outputs from the attached photovoltaic cells monitored for a period of slightly over one year in the solar noise barrier (SONOB) “living lab” outdoor environment. The results of the edge electric output measurements were compared to ray-tracing simulations, revealing imperfections in the system design and production that resulted in the significantly reduced performance of the panel compared to expectations. Results of these calculations suggest edge emission improvements of a factor of 6–9 are possible: at these improved edge outputs, the LSC becomes a viable solar energy generator for the built environment, with significant visual appeal. A grey-box computer model has been developed to predict LSC performance using a realistic device design with reduced internal light scattering and better photovoltaic cell positioning. A second model is used for extrapolation of the LSC solar barrier electric performance with different orientations in different world locations.

Indoor air quality and thermal comfort of existing naturally ventilated classrooms in the Indian capital territory, Delhi, is substandard. This should be improved while trying to prevent the increase in energy demand. The research question focused on solution options to answer these contradictory requirements.

Oververhitting is een punt van zorg in woningen en andere gebouwen waar mensen verblijven. De veronderstelde veranderingen in het klimaat en daarnaast de lokale gevolgen van het zogenaamde ‘urban heat island’ effect kan het probleem doen toenemen. Is dit een mogelijk probleem in laag energie woningen, en hoe kunnen we hierop anticiperen. Dit artikel is een uitgebreide samenvatting van de presentatie, die is gegeven op het ISIAQ.nl symposium aan de TU Eindhoven op 5 april 2018.

Shading devices are effective in controlling glare and solar heat gains in buildings. However, this occurs at the expense of daylight and outside view. This paper evaluates the thermal and daylight performance of Lumiduct, a sun-controlling dynamic façade system that permits only diffuse radiation inside the building, while producing electricity. This imparts Lumiduct a unique characteristic of acting as a shading device while providing useful daylight and view to the outside. The first part of the paper briefly illustrates the working principle of Lumiduct and its functional characteristics and then, introduces the basic principles of the modelling and simulation strategy used to predict its performance. To demonstrate this strategy we use TypeDLT, a TRNSYS type that performs integrated thermal and daylight simulations by coupling TRNSYS’ multi-zone building model with Radiance’s three-phase method. This strategy relies on the use of customized and time-controlled bidirectional scattering distribution functions (BSDF) to characterize the separate treatment of direct and diffuse radiation and the sun-tracking behaviour of the façade. In the second part, we demonstrate the performance of Lumiduct in comparison to a high-performance window with and without a dynamic venetian blind system as a shading device for a typical office room for the climate of Amsterdam. The results show a significantly higher daylight utilization along with a reduction in energy use of the building.

Diverse studies hebben het belang van het monitoren van gebouwen in gebruik aangetoond. De verzamelde data geeft inzicht in het energieverbruik en de binnenklimaatkwaliteit van gebouwen en kan worden ingezet om de prestatie van gebouwen te controleren en optimaliseren. Echter in de huidige normen, als ISO 7730, NEN-EN 1525, ANSI/ASHRAE standard 55 en Nederlandse ISSO-richtlijnen wordt weinig informatie verstrekt over het constant meten van het binnenklimaat in open-kantoorvloeren. Deze situatie kan leiden tot incorrecte conclusies, waarbij gemeten data onvoldoende de werkelijke comfortomstandigheden weerspiegelen. Dit kan weer gevolgen hebben voor de gezondheid en productiviteit van de werknemers en het energieverbruik van het gebouw. Om in de toekomst de binnenklimaatkwaliteit van open-kantoorvloeren nauwkeuriger te bepalen met behulp van sensoren, zijn in dit onderzoek het aantal en de positie van de sensoren ter discussie gesteld.

Existing guidelines on monitoring of Indoor Climate Quality (ICQ) do not adequately address long term monitoring. A better understanding of the collection and analysis of monitored data, extending over a longtime period is required. This study aimed at addressing the aforementioned research gaps. The study took place in two office buildings, during two periods each: February & May (case I) and April & June (case II). Thermal nvironment data was obtained across several locations in the room. Results showed that measurement of temperature was most critical in the openplan office floors. Local heat sources had a significant influence on the measured temperatures. To collect representative data with the help of building management system (BMS) sensors, existence and fluctuation of local heat sources should be considered at the start of the ICQ assessment. Based on this information, the minimal distance between BMS sensor and workplace location can be determined. In the design process, the field study protocol can be used as a tool to predict the number of sensors and distance from occupants.

India's capital, New Delhi, struggles with high outdoor air pollution and extreme temperatures during summer and winter. Together they are liable to adversely affect health and learning of children in classrooms without mechanical ventilation and cooling. This work targets to provide a guideline on how to sustainably improve the indoor climate quality in such classrooms with a weighing of the measures against investment cost and energy needs. The current conditions in classrooms of 5 schools located in the National Capital Territory of Delhi were analysed. Major parts of these schools were completely reliant on natural ventilation. Thus indoor to outdoor PM2.5 concentration ratio remained close to 1. During summer, indoor temperature rises up to 40 °C. During winter, indoor CO2 concentration can exceed 1150 ppm. Using monitored conditions as input, a TRNSYS base model was created for the classrooms. This model functions as a test environment for proposed interventions towards improving indoor climate quality. The proposed solutions target CO2 level ≤ 1150 ppm, PM2.5 ≤ 25μg/m3 and temperatures within 80% acceptability range of the Indian adaptive thermal comfort model.

The increasing digitalisation of data is resulting in the need for ever greater computational capacity, which in turn leads to the increasing energy consumption in data centres. A large percentage of this energy use arises from the need to mechanically remove an enormous amount of heat from the data centre environment. In fact, in current practice, the mechanical infrastructure (especially cooling systems) of the data centre accounts for up to half of the overall energy consumption. To reduce the energy consumption of the mechanical infrastructure, several economisation methods are commonly implemented in cooling systems, one of which is the application of a direct air-side economiser addressed in the current research. The use of an air-side economiser has been shown to lead to major savings of the cooling electricity demand, and, as such, it has been widely used as a necessary addition to conventional cooling systems. This study analyses the energy breakdown of data centre cooling systems that include an air-side economiser in order to determine which components within the system are responsible for the major energy consumption. This study investigates, via a computational simulation, the impact of the use of a conventional cooling system and a system with an air-side economiser on total energy demand in three locations representing different climate regions in Europe. The study is especially focused on the energy demand related to the humidity treatment in the data rooms, since the effect is rarely considered in the overall DC energy balance. The results demonstrate, as expected, that the air-side economiser can yield major savings of around 62.5% to 78.7%, depending on the given climate regions. However, the key result of this study is that the humidity treatment necessary for the direct air-side economiser system may consume up to 34.8% of the total energy demand of the cooling system with the air-side economiser.