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Decentral monitoring as a contribution towards improving indoor comfort and operation of commercial buildings Many existing non‐residential buildings offer potential for improving the indoor climate and energy performance through improved use and operational management. To do this, however, the conditions must first be measured and assessed so that recommendations for action can be developed. Existing building automation systems are often not sufficiently qualified for these activities. A corresponding expansion of the hardware and/or software is often economically disproportionate. Against this background, room climate measurements were carried out in exemplary buildings with decentralised data loggers of different designs over at least one year. The three buildings selected for this paper have very different ventilation concepts. The two buildings without air conditioning systems showed the influence of user behaviour on the achieved indoor climate level in different ways. The building with an air‐handling system exemplified the influence of an unfavourable set point on energy consumption. Decentralised measurement technology offers great potential for quality assurance in existing buildings. In new buildings, it is necessary to design building automation systems for quality assurance tasks and not only for function assurance. [ABSTRACT FROM AUTHOR]

Diese Artikelserie stellt den Einsatz von Computerprogrammen in der Hochschullehre der Bauphysik und Gebäudetechnik für Architekten und Bauingenieure vor. In diesem Beitrag werden die Motivation zur Artikelserie und die Ergebnisse einer Online‐Umfrage an die Lehrenden der deutschsprachigen Hochschulen, initiiert und durchgeführt vom Fachgebiet Bauphysik und Technische Gebäudeausrüstung der Universität Wuppertal, aufgeführt. [ABSTRACT FROM AUTHOR]

Im Zuge der Erforschung des Klimawandels sind die Prognosemodelle in den letzten Jahren soweit verbessert worden, dass lokale und regionale Klimadatensätze für die Anwendung in Energieberechnungsverfahren für Gebäude vorliegen. Der Beitrag analysiert die Datensätze aus den aktuell verfügbaren Quellen und stellt die relevanten Charakteristika gegenüber. Mit Simulationsrechnungen anhand von drei Nichtwohngebäuden (Büro, Schule, Hotel) wird aufgezeigt, wie sich die Klimadaten auf den Energiebedarf, den Leistungsbedarf und den thermischen Komfort auswirken, sofern keinerlei Anpassungen bei der Baukonstruktion, der Anlagentechnik oder dem Nutzerverhalten erfolgen. Einem deutlich sinkenden Heizwärmebedarf steht bis 2050 eine Zunahme der sommerlichen Raumtemperaturen bzw. des Kältebedarfs gegenüber. Die sommerliche Situation wird insbesondere für Bürobauten kritisch, so dass technische Anlagen zur Kühlung in den sommerheißen Regionen erforderlich werden. Dieser Trend wurde bereits in den vergangenen Jahren beobachtet. Während es für Neubauten dazu energieeffiziente Lösungen gibt, ist die Entwicklung für Bestandsgebäude kritisch. Hier sind wesentliche Verbesserungen von Sonnenschutz und Lüftungsstrategien erforderlich. Für Schulen und Hotels fallen die zu erwartenden Veränderungen vergleichsweise moderat aus. Climate data and climate change - Analysis of the influence on energy demand, performance requirement and thermal comfort of buildings. Continuous research on climate change has improved the knowledge on climate forecast modelling, so that local and regional climate data sets for the application in building energy modelling are available. The paper analyses the data sets of most known sources and compares the relevant characteristics at four German locations. Simulation results for three commercial building examples (office, school and hotel) illustrate how the climate change may influence heating and cooling demands and capacities as well as the summer thermal comfort if no adjustments with respect to construction, service technology and user behaviour are applied. A significant decrease in space heating demand is contrasted by increased cooling demand and increased indoor temperatures during summer even until 2050. Especially for the office buildings, the summer conditions develop critical, so that active cooling will be mandatory in the summer hot regions. This trend was already detected during the past decade. The forecast is critical for all existing buildings. Significant improvements of the envelope properties such as glazing or shading and passive cooling options become mandatory. The changes predicted for schools and hotels remain moderate. [ABSTRACT FROM AUTHOR]

Ceiling fans allow an increase of the local air velocity on the human body. The associated heat transfer increases user's temperature tolerance in warm environments. In the presented study, the differences in the application of statistical turbulence models (RANS) for modelling the air flow induced by a ceiling integrated fan is outlined with particular focus on comparing steady and transient simulations. Results of a CFD simulation (Fluent) are shown and compared with measured data of the horizontal velocity distribution. The study shows that especially the transient simulation using the Realizable k‐ε model shows a stable convergence behaviour regarding the residuals as well as target values. But at 1.1 m above the floor, the mean absolute error of the transient simulation is larger compared to the stationary model using the Multiple Reference Frame (MRF) approach. Despite the stationary model produces an unrealistic velocity distribution in the immediate vicinity of the fan, if the moving zone needs to be small due to obstacles. For a freely suspended ceiling fan, the moving zone can be adjusted accordingly and the flow pattern can be improved. But modelling a ceiling integrated fan with a fan housing and obstacles in the near region, transient simulations using rigid body motion are required for accurate results. [ABSTRACT FROM AUTHOR]

In‐situ measurement of massive building components – Part 1: Comparison of test methods and influences in heating chamber tests In‐situ U‐value measurements are suitable for opaque constructions where a non‐destructive testing of thermal properties is required, e.g. for renovation. In‐situ U‐value measurements are the subject of two research projects from Germany and Switzerland. This Part 1 presents results of the project "LivingLab – Building Performance" at the University of Wuppertal. The aim is to investigate influences on in‐situ U‐value measurement methods for masonry structures in a hot box. It is shown, that in heat flux methods with long measurement periods, size of the heat flux plates and their positioning with respect to mortar joints do not show measurable differences. For uninsulated constructions, this method tends to show lower U‐values, for insulated constructions higher U‐values than calculated. In comparison, short‐term measurements are performed using so‐called "Rapid‐U‐Value Technique (Rapid‐U)". Larger scattering of the results and higher U‐values than with the heat flow method are shown. In Part 2, a research project from Switzerland is presented, in the context of which a practice‐oriented application aid for in‐situ U‐value measurement is being developed. In‐situ U‐value measurements using three different instruments and comparative measurements in the laboratory serve as a basis. [ABSTRACT FROM AUTHOR]

This study examines the use of tetrahedral [E(O-C6X4-CN)4]- anions (E = B, Al; X = H, F), which can be synthesized from the reaction of tetrahedral NaBH4/LiAlH4 and HO-C6X4-CN, as anionic linkers for the generation of 2D and 3D crystalline coordination polymer networks. Such polymer networks were obtained by the connection of tetrahedral p-cyanophenoxy aluminate or borate linkers with monocationic metal centers such as Li+, Na+, Ag+, and Cu+. These studies are specifically focused on the synthesis, structure, and stability of such polymers. Additionally, the perfluorinated O-C6F4-CN linker was used to study electronic influences. Salts bearing the perfluorinated [E(O-C6F4-CN)4]- anion decompose into E(O-C6F4-CN)3 and [O-C6F4-CN]-, which is also observed when a Lewis acid such as B(C6F5)3 is added. Moreover, addition of B(C6F5)3 leads to the formation of molecular-ion pairs because the cyano groups are now either completely or partly blocked. The structures of M[Al(O-C6H4-CN)4] (M = Li, Ag, Cu), Na[B(O-C6H4-CN)4], and Li[Al(O-C6F4-CN)4] as well as of the decomposition products Na(O-C6F4-CN), (THF)Al[O-C6H4-CN ·B(C6F5)3]3 (THF = tetrahydrofuran), Na[(F5C6)3B ·O-C6H4-CN ·B(C6F5)3], and Li[NC-C6F4-O-Al{O-C6F4-CN ·B(C6F5)3}3] are discussed. [ABSTRACT FROM AUTHOR]