@article{PollackLueckWolfetal.,
  author    = {Pollack, Moritz and L{\"u}ck, Andrea and Wolf, Mario and Kraft, Eckhard and V{\"o}lker, Conrad},
  title     = {Energy and Business Synergy: Leveraging Biogenic Resources from Agriculture, Waste, and Wastewater in German Rural Areas},
  series = {Sustainability},
  volume    = {2023},
  journal   = {Sustainability},
  number    = {volume 15, issue 24, article 16573},
  publisher = {MDPI},
  address   = {Basel},
  doi       = {10.3390/su152416573},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20231222-65172},
  pages     = {1 -- 25},
  abstract  = {The imperative to transform current energy provisions is widely acknowledged. However, scant attention has hitherto been directed toward rural municipalities and their innate resources, notably biogenic resources. In this paper, a methodological framework is developed to interconnect resources from waste, wastewater, and agricultural domains for energy utilization. This entails cataloging existing resources, delineating their potential via quantitative assessments utilizing diverse technologies, and encapsulating them in a conceptual model. The formulated models underwent iterative evaluation with engagement from diverse stakeholders. Consequently, 3 main concepts, complemented by 72 sub-concepts, were delineated, all fostering positive contributions to climate protection and providing heat supply in the rural study area. The outcomes' replicability is underscored by the study area's generic structure and the employed methodology. Through these inquiries, a framework for the requisite energy transition, with a pronounced emphasis on the coupling of waste, wastewater, and agriculture sectors in rural environments, is robustly analyzed.},
  subject      = {Energiewende},
  language  = {en}
}
@inproceedings{KieselEngelsVoelker,
  author    = {Kiesel, Gerd and Engels, Merit and V{\"o}lker, Conrad},
  title     = {Energetische Transformation im l{\"a}ndlichen Raum - Aufbau eines prozessorientierten Entwicklungs- und Moderationsmodells},
  series = {Schriftenreihe des Fachgebiets Bauphysik/Energetische Geb{\"a}udeoptimierung},
  booktitle = {Schriftenreihe des Fachgebiets Bauphysik/Energetische Geb{\"a}udeoptimierung},
  editor    = {Kornadt, Oliver and Carrigan, Svenja and Hofmann, Markus and V{\"o}lker, Conrad},
  publisher = {Eigenverlag Technische Universit{\"a}t Kaiserslautern},
  address   = {Kaiserslautern},
  isbn      = {978-3-95974-176-7},
  issn      = {2363-8206},
  doi       = {10.25643/bauhaus-universitaet.4656},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220617-46566},
  pages     = {3},
  abstract  = {Kleine Kommunen im l{\"a}ndlichen Raum sind aufgrund ihrer oft eingeschr{\"a}nkten personellen und finanziellen Kapazit{\"a}ten bisher eher sporadisch in den Themenfeldern Energieeffizienz und Erneuerbare Energien aktiv. Immer wieder stellt sich daher Frage, wie die Klimaschutzstrategien des Bundes und der L{\"a}nder dort mit dem verf{\"u}gbaren Personal kosteng{\"u}nstig realisierbar sind. Vor diesem Hintergrund wird ein Werkzeug entwickelt, mit dessen Hilfe der aktive Einstieg in diese Thematik mit geringen Aufwand und {\"u}berwiegend barrierefrei m{\"o}glich ist. Der Aufbau eines prozessorientierten Entwicklungs- und Moderationsmodells zur Erprobung und Umsetzung bezahlbarer Handlungsoptionen f{\"u}r Energieeinsparungen und effizienten Energieeinsatz im {\"u}berwiegend l{\"a}ndlichen gepr{\"a}gten Raum ist der Schwerpunkt der Softwarel{\"o}sung. Kommunen werden mit deren Hilfe in die Lage versetzt, in die notwendigen Prozesse der Energie- und W{\"a}rmewende einzusteigen. Dabei soll der modulare Aufbau die regul{\"a}ren Schritte notwendiger (integrierter) Planungsprozesse nicht vollst{\"a}ndig ersetzen. Vielmehr k{\"o}nnen innerhalb der Online-Anwendung - {\"u}berwiegend automatisiert - konkrete Maßnahmenvorschl{\"a}ge erstellt werden, die ein solides Fundament der k{\"u}nftigen energetischen Entwicklung der Kommunen darstellen. F{\"u}r eine gezielte Validierung der Ergebnisse und der Ableitung potentieller Maßnahmen werden f{\"u}r die Erprobung Modellkommunen in Th{\"u}ringen, Bayern und Hessen als Reallabore einbezogen. Das Tool steht bisher zun{\"a}chst nur den beteiligten Modellkommunen zur Verf{\"u}gung. Die entwickelte Softwarel{\"o}sung soll k{\"u}nftig Schritt f{\"u}r Schritt allen interessierten Kommunen mit diversen Hilfsmitteln und einer Vielzahl anderer praktischer Bestandteile zur Verf{\"u}gung gestellt werden.},
  subject      = {Modellierung},
  language  = {de}
}
@inproceedings{HartmannAlsaadVoelker,
  author    = {Hartmann, Maria and Alsaad, Hayder and V{\"o}lker, Conrad},
  title     = {Das Potential von Fassadenbegr{\"u}nungen zur Verringerung des W{\"a}rmeinseleffekts: Simulation eines Beispielquartiers},
  series = {Bauphysiktage Kaiserslautern 2022},
  booktitle = {Bauphysiktage Kaiserslautern 2022},
  address   = {Kaiserslautern},
  isbn      = {978-3-95974-176-7},
  issn      = {2363-8206},
  doi       = {10.25643/bauhaus-universitaet.4667},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220713-46676},
  pages     = {147-149},
  abstract  = {Die Auswirkungen einer Fassadenbegr{\"u}nung auf den W{\"a}rmeinseleffekt in Stuttgart wurde f{\"u}r eine Hitzeperiode numerisch simuliert und bewertet. Die Ergebnisse zeigten positive Auswirkungen innerhalb des Simulationsgebiets sowie eine geringe Fernwirkung auf benachbarte Stadtquartiere. Diese {\"A}nderungen k{\"o}nnen zur Verbesserung des thermischen Komforts im Außenraum beitragen. Eine reduzierte Temperatur der Außenoberfl{\"a}che f{\"u}hrt dar{\"u}ber hinaus auch zu einer geringeren Oberfl{\"a}chentemperatur der Wandinnenseite, welche die Innenraumtemperatur beeinflusst. Folglich kann die thermische Behaglichkeit auch im Innenraum erh{\"o}ht werden.},
  subject      = {Mikroklima},
  language  = {de}
}
@inproceedings{GeskeBenzVoelker,
  author    = {Geske, Mara and Benz, Alexander and V{\"o}lker, Conrad},
  title     = {Anwendung georeferenzierter Bilddaten bei energetischen Quartiersanalysen},
  series = {Tagungsband Bauphysiktage Kaiserslautern 2022},
  booktitle = {Tagungsband Bauphysiktage Kaiserslautern 2022},
  editor    = {Kornadt, Oliver and Carrigan, Svenja and Hofmann, Markus and V{\"o}lker, Conrad},
  publisher = {Eigenverlag der Technischen Universit{\"a}t Kaiserslautern},
  address   = {Kaiserslautern},
  isbn      = {987-3-95974-176-7},
  issn      = {2363-8206},
  doi       = {10.25643/bauhaus-universitaet.4654},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220617-46544},
  pages     = {127-129},
  abstract  = {Bei Analysen des Geb{\"a}udebestands im Quartierskontext werden zu Dokumentationszwecken viele Bilddaten erzeugt. Diese Daten sind im Nachhinein h{\"a}ufig keinen eindeutig genauen Standorten und Blickwinkeln auf das Bauwerk zuzuordnen. Insbesondere gilt dies f{\"u}r Ortsunkundige oder f{\"u}r Detailaufnahmen. Eine zus{\"a}tzliche Herausforderung stellt die Aufnahme von W{\"a}rmebr{\"u}cken- oder andersartigen Geb{\"a}udedetails durch Thermogramme dar. In der Praxis kommen hier oftmals analoge, fehleranf{\"a}llige L{\"o}sungen zum Einsatz. Durch die Nutzung von Georeferenzierung kann diese L{\"u}cke geschlossen und eine eindeutige Kommunikation und Auswertung gew{\"a}hrleistet werden. Im Gegensatz zu den {\"u}blichen Kameras sind Smartphones nach Stand der Technik ausreichend ausgestattet, um neben Daten zu Standort auch die Orientierungswinkel einer Bildaufnahme zu dokumentieren. Die georefenzierten Bilder k{\"o}nnen auf Grundlage der in den sogenannten Exif-Daten mitgeschriebenen Informationen h{\"a}ndisch in ein bestehendes Quartiersmodell integriert werden. Anhand eines universit{\"a}ren Musterquartiers wird die nutzerfreundliche Realisierung beispielhaft erprobt und auf ihre Potentiale zur Automatisierung in Python untersucht. Hierf{\"u}r wurde ein bestehendes Quartiersmodell als geometrische Grundlage genutzt und um RGB-Bilder sowie Thermogramme erweitert. Das beschriebene Vorgehen wird im Rahmen der Anwendung auf seinen m{\"o}glichen Einsatz im Rahmen einer energetischen Quartierserfassung sowie einer Bauschadensdokumentation untersucht. Mit dem vorliegenden Beitrag wird dem Nutzenden ein Werkzeug bereitgestellt, das die hochwertige Dokumentation einer Bestandserfassung, auch im Quartierskontext, erm{\"o}glicht.},
  subject      = {Quartiersanalyse},
  language  = {de}
}
@article{AlsaadHartmannVoelker,
  author    = {Alsaad, Hayder and Hartmann, Maria and V{\"o}lker, Conrad},
  title     = {Hygrothermal simulation data of a living wall system for decentralized greywater treatment},
  series = {Data in Brief},
  volume    = {2022},
  journal   = {Data in Brief},
  number    = {volume 40, article 107741},
  publisher = {Elsevier},
  address   = {Amsterdam},
  doi       = {10.1016/j.dib.2021.107741},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220106-45483},
  pages     = {12},
  abstract  = {This dataset presents the numerical analysis of the heat and moisture transport through a facade equipped with a living wall system designated for greywater treatment. While such greening systems provide many environmental benefits, they involve pumping large quantities of water onto the wall assembly, which can increase the risk of moisture in the wall as well as impaired energetic performance due to increased thermal conductivity with increased moisture content in the building materials. This dataset was acquired through numerical simulation using the coupling of two simulation tools, namely Envi-Met and Delphin. This coupling was used to include the complex role the plants play in shaping the near-wall environmental parameters in the hygrothermal simulations. Four different wall assemblies were investigated, each assembly was assessed twice: with and without the living wall. The presented data include the input and output parameters of the simulations, which were presented in the co-submitted article [1].},
  subject      = {Kupplung},
  language  = {en}
}
@article{TeitelbaumAlsaadAvivetal.,
  author    = {Teitelbaum, Eric and Alsaad, Hayder and Aviv, Dorit and Kim, Alexander and V{\"o}lker, Conrad and Meggers, Forrest and Pantelic, Jovan},
  title     = {Addressing a systematic error correcting for free and mixed convection when measuring mean radiant temperature with globe thermometers},
  series = {Scientific reports},
  volume    = {2022},
  journal   = {Scientific reports},
  number    = {Volume 12, article 6473},
  publisher = {Springer Nature},
  address   = {London},
  doi       = {10.1038/s41598-022-10172-5},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220509-46363},
  pages     = {18},
  abstract  = {It is widely accepted that most people spend the majority of their lives indoors. Most individuals do not realize that while indoors, roughly half of heat exchange affecting their thermal comfort is in the form of thermal infrared radiation. We show that while researchers have been aware of its thermal comfort significance over the past century, systemic error has crept into the most common evaluation techniques, preventing adequate characterization of the radiant environment. Measuring and characterizing radiant heat transfer is a critical component of both building energy efficiency and occupant thermal comfort and productivity. Globe thermometers are typically used to measure mean radiant temperature (MRT), a commonly used metric for accounting for the radiant effects of an environment at a point in space. In this paper we extend previous field work to a controlled laboratory setting to (1) rigorously demonstrate that existing correction factors used in the American Society of Heating Ventilation and Air-conditioning Engineers (ASHRAE) Standard 55 or ISO7726 for using globe thermometers to quantify MRT are not sufficient; (2) develop a correction to improve the use of globe thermometers to address problems in the current standards; and (3) show that mean radiant temperature measured with ping-pong ball-sized globe thermometers is not reliable due to a stochastic convective bias. We also provide an analysis of the maximum precision of globe sensors themselves, a piece missing from the domain in contemporary literature.},
  subject      = {Strahlungstemperatur},
  language  = {en}
}
@article{AlsaadHartmannHilbeletal.,
  author    = {Alsaad, Hayder and Hartmann, Maria and Hilbel, Rebecca and V{\"o}lker, Conrad},
  title     = {ENVI-met validation data accompanied with simulation data of the impact of facade greening on the urban microclimate},
  series = {Data in Brief},
  volume    = {2022},
  journal   = {Data in Brief},
  number    = {Volume 42, article 108200},
  publisher = {Elsevier},
  address   = {Amsterdam},
  doi       = {10.1016/j.dib.2022.108200},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220511-46455},
  pages     = {1 -- 13},
  abstract  = {This dataset consists mainly of two subsets. The first subset includes measurements and simulation data conducted to validate the simulation tool ENVI-met. The measurements were conducted at the campus of the Bauhaus-University Weimar in Weimar, Germany and consisted of recording exterior air temperature, globe temperature, relative humidity, and wind velocity at 1.5 m at four points on four different days. After the measurements, the geometry of the campus was modelled and meshed; the simulations were conducted using the weather data of the measurements days with the aim of investigating the accuracy of the model. The second data subset consists of ENVI-met simulation data of the potential of facade greening in improving the outdoor environment and the indoor air temperature during heatwaves in Central European cities. The data consist of the boundary conditions and the simulation output of two simulation models: with and without facade greening. The geometry of the models corresponded to a residential buildings district in Stuttgart, Germany. The simulation output consisted of exterior air temperature, mean radiant temperature, relative humidity, and wind velocity at 12 different probe points in the model in addition to the indoor air temperature of an exemplary building. The dataset presents both vertical profiles of the probed parameters as well as the time series output of the five-day simulation duration. Both data subsets correspond to the investigations presented in the co-submitted article [1].},
  subject      = {Messung},
  language  = {en}
}
@article{AlsaadVoelker,
  author    = {Alsaad, Hayder and V{\"o}lker, Conrad},
  title     = {Qualitative evaluation of the flow supplied by personalized ventilation using schlieren imaging and thermography},
  series = {Building and Environment},
  volume    = {2020},
  journal   = {Building and Environment},
  number    = {Volume 167, article 106450},
  publisher = {Elsevier},
  address   = {New York},
  doi       = {10.25643/bauhaus-universitaet.4511},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20211008-45117},
  pages     = {11},
  abstract  = {Personalized ventilation (PV) is a mean of delivering conditioned outdoor air into the breathing zone of the occupants. This study aims to qualitatively investigate the personalized flows using two methods of visualization: (1) schlieren imaging using a large schlieren mirror and (2) thermography using an infrared camera. While the schlieren imaging was used to render the velocity and mass transport of the supplied flow, thermography was implemented to visualize the air temperature distribution induced by the PV. Both studies were conducted using a thermal manikin to simulate an occupant facing a PV outlet. As a reference, the flow supplied by an axial fan and a cased axial fan was visualized with the schlieren system as well and compared to the flow supplied by PV. Schlieren visualization results indicate that the steady, low-turbulence flow supplied by PV was able to penetrate the thermal convective boundary layer encasing the manikin's body, providing clean air for inhalation. Contrarily, the axial fan diffused the supplied air over a large target area with high turbulence intensity; it only disturbed the convective boundary layer rather than destroying it. The cased fan supplied a flow with a reduced target area which allowed supplying more air into the breathing zone compared to the fan. The results of thermography visualization showed that the supplied cool air from PV penetrated the corona-shaped thermal boundary layer. Furthermore, the supplied air cooled the surface temperature of the face, which indicates the large impact of PV on local thermal sensation and comfort.},
  subject      = {Bildverarbeitung},
  language  = {en}
}
@inproceedings{AlsaadVoelker,
  author    = {Alsaad, Hayder and V{\"o}lker, Conrad},
  title     = {Measuring and visualizing the flow supplied by personalized ventilation},
  series = {Proceedings Book Roomvent 2020},
  booktitle = {Proceedings Book Roomvent 2020},
  address   = {Turin, Italy},
  doi       = {10.25643/bauhaus-universitaet.4657},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220622-46573},
  abstract  = {This study investigates the flow supplied by personalized ventilation (PV) by means of anemometer measurements and schlieren visualization. The study was conducted using a thermal manikin to simulate a seated occupant facing a PV outlet. Air velocity was measured at multiple points in the flow field; the collected velocity values were used to calculate the turbulence intensity. Results indicated that PV was supplying air with low turbulence intensity that was able to penetrate the convective boundary layer of the manikin to supply clean air for inhalation. The convective boundary layer, however, obstructed the supplied flow and reduced its velocity by a total of 0.26 m/s. The PV flow preserved its value until about 10 cm from the face where velocity started to drop. Further investigations were conducted to test a PV diffuser with a relatively large outlet diameter (18 cm). This diffuser was developed using 3d-modelling and 3d-printing. The diffuser successfully distributed the flow over the larger outlet area. However, the supplied velocity and turbulence fields were not uniform across the section.},
  subject      = {Bel{\"u}ftung},
  language  = {en}
}
@article{BecherGenaAlsaadetal.,
  author    = {Becher, Lia and Gena, Amayu Wakoya and Alsaad, Hayder and Richter, Bernhard and Spahn, Claudia and V{\"o}lker, Conrad},
  title     = {The spread of breathing air from wind instruments and singers using schlieren techniques},
  series = {Indoor Air},
  volume    = {2021},
  journal   = {Indoor Air},
  number    = {volume 31, issue 6},
  publisher = {Wiley Blackwell},
  address   = {Oxford},
  doi       = {10.1111/ina.12869},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220209-45817},
  pages     = {1798 -- 1814},
  abstract  = {The spread of breathing air when playing wind instruments and singing was investigated and visualized using two methods: (1) schlieren imaging with a schlieren mirror and (2) background-oriented schlieren (BOS). These methods visualize airflow by visualizing density gradients in transparent media. The playing of professional woodwind and brass instrument players, as well as professional classical trained singers were investigated to estimate the spread distances of the breathing air. For a better comparison and consistent measurement series, a single high note, a single low note, and an extract of a musical piece were investigated. Additionally, anemometry was used to determine the velocity of the spreading breathing air and the extent to which it was quantifiable. The results showed that the ejected airflow from the examined instruments and singers did not exceed a spreading range of 1.2 m into the room. However, differences in the various instruments have to be considered to assess properly the spread of the breathing air. The findings discussed below help to estimate the risk of cross-infection for wind instrument players and singers and to develop efficacious safety precautions, which is essential during critical health periods such as the current COVID-19 pandemic.},
  subject      = {Covid-19},
  language  = {en}
}
@article{DokhanchiArnoldVogeletal.2020,
  author    = {Dokhanchi, Najmeh Sadat and Arnold, J{\"o}rg and Vogel, Albert and V{\"o}lker, Conrad},
  title     = {Measurement of indoor air temperature distribution using acoustic travel-time tomography: Optimization of transducers location and sound-ray coverage of the room},
  series = {Measurement},
  volume    = {2020},
  journal   = {Measurement},
  number    = {Volume 164, article 107934},
  publisher = {Elsevier},
  address   = {Amsterdam},
  doi       = {10.1016/j.measurement.2020.107934},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220524-46473},
  year      = {2020},
  abstract  = {Acoustic travel-time TOMography (ATOM) allows the measurement and reconstruction of air temperature distributions. Due to limiting factors, such as the challenge of travel-time estimation of the early reflections in the room impulse response, which heavily depends on the position of transducers inside the measurement area, ATOM is applied mainly outdoors. To apply ATOM in buildings, this paper presents a numerical solution to optimize the positions of transducers. This optimization avoids reflection overlaps, leading to distinguishable travel-times in the impulse response reflectogram. To increase the accuracy of the measured temperature within tomographic voxels, an additional function is employed to the proposed numerical method to minimize the number of sound-path-free voxels, ensuring the best sound-ray coverage of the room. Subsequently, an experimental set-up has been performed to verify the proposed numerical method. The results indicate the positive impact of the optimal positions of transducers on the distribution of ATOM-temperatures.},
  subject      = {Bauphysik},
  language  = {en}
}
@article{BecherVoelkerRodehorstetal.,
  author    = {Becher, Lia and V{\"o}lker, Conrad and Rodehorst, Volker and Kuhne, Michael},
  title     = {Background-oriented schlieren technique for two-dimensional visualization of convective indoor air flows},
  series = {Optics and Lasers in Engineering},
  volume    = {2020},
  journal   = {Optics and Lasers in Engineering},
  number    = {Volume 134, article 106282},
  doi       = {https://doi.org/10.1016/j.optlaseng.2020.106282},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220810-46972},
  pages     = {9},
  abstract  = {This article focuses on further developments of the background-oriented schlieren (BOS) technique to visualize convective indoor air flow, which is usually defined by very small density gradients. Since the light rays deflect when passing through fluids with different densities, BOS can detect the resulting refractive index gradients as integration along a line of sight. In this paper, the BOS technique is used to yield a two-dimensional visualization of small density gradients. The novelty of the described method is the implementation of a highly sensitive BOS setup to visualize the ascending thermal plume from a heated thermal manikin with temperature differences of minimum 1 K. To guarantee steady boundary conditions, the thermal manikin was seated in a climate laboratory. For the experimental investigations, a high-resolution DLSR camera was used capturing a large field of view with sufficient detail accuracy. Several parameters such as various backgrounds, focal lengths, room air temperatures, and distances between the object of investigation, camera, and structured background were tested to find the most suitable parameters to visualize convective indoor air flow. Besides these measurements, this paper presents the analyzing method using cross-correlation algorithms and finally the results of visualizing the convective indoor air flow with BOS. The highly sensitive BOS setup presented in this article complements the commonly used invasive methods that highly influence weak air flows.},
  subject      = {Raumklima},
  language  = {en}
}
@article{AlsaadVoelker,
  author    = {Alsaad, Hayder and V{\"o}lker, Conrad},
  title     = {Der K{\"u}hlungseffekt der personalisierten L{\"u}ftung},
  series = {Bauphysik},
  volume    = {2020},
  journal   = {Bauphysik},
  number    = {volume 42, issue 5},
  publisher = {Ernst \& Sohn bei John Wiley \& Sons},
  address   = {Hoboken},
  doi       = {10.25643/bauhaus-universitaet.4272},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20201020-42723},
  pages     = {218 -- 225},
  abstract  = {Personalisierte L{\"u}ftung (PL) kann die thermische Behaglichkeit sowie die Qualit{\"a}t der eingeatmeten Atemluft verbessern, in dem jedem Arbeitsplatz Frischluft separat zugef{\"u}hrt wird. In diesem Beitrag wird die Wirkung der PL auf die thermische Behaglichkeit der Nutzer unter sommerlichen Randbedingungen untersucht. Hierf{\"u}r wurden zwei Ans{\"a}tze zur Bewertung des K{\"u}hlungseffekts der PL untersucht: basierend auf (1) der {\"a}quivalenten Temperatur und (2) dem thermischen Empfinden. Grundlage der Auswertung sind in einer Klimakammer gemessene sowie numerisch simulierte Daten. Vor der Durchf{\"u}hrung der Simulationen wurde das numerische Modell zun{\"a}chst anhand der gemessenen Daten validiert. Die Ergebnisse zeigen, dass der Ansatz basierend auf dem thermischen Empfinden zur Evaluierung des K{\"u}hlungseffekts der PL sinnvoller sein kann, da bei diesem die komplexen physiologischen Faktoren besser ber{\"u}cksichtigt werden.},
  subject      = {L{\"u}ftung},
  language  = {de}
}
@article{AlsaadVoelker,
  author    = {Alsaad, Hayder and V{\"o}lker, Conrad},
  title     = {Performance evaluation of ductless personalized ventilation in comparison with desk fans using numerical simulations},
  series = {Indoor Air},
  volume    = {2020},
  journal   = {Indoor Air},
  publisher = {John Wiley \& Sons Ltd},
  doi       = {10.1111/ina.12672},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200422-41407},
  pages     = {14},
  abstract  = {The performance of ductless personalized ventilation (DPV) was compared to the performance of a typical desk fan since they are both stand-alone systems that allow the users to personalize their indoor environment. The two systems were evaluated using a validated computational fluid dynamics (CFD) model of an office room occupied by two users. To investigate the impact of DPV and the fan on the inhaled air quality, two types of contamination sources were modelled in the domain: an active source and a passive source. Additionally, the influence of the compared systems on thermal comfort was assessed using the coupling of CFD with the comfort model developed by the University of California, Berkeley (UCB model). Results indicated that DPV performed generally better than the desk fan. It provided better thermal comfort and showed a superior performance in removing the exhaled contaminants. However, the desk fan performed better in removing the contaminants emitted from a passive source near the floor level. This indicates that the performance of DPV and desk fans depends highly on the location of the contamination source. Moreover, the simulations showed that both systems increased the spread of exhaled contamination when used by the source occupant.},
  subject      = {Behaglichkeit},
  language  = {en}
}
@article{AlsaadVoelker,
  author    = {Alsaad, Hayder and V{\"o}lker, Conrad},
  title     = {Could the ductless personalized ventilation be an alternative to the regular ducted personalized ventilation?},
  series = {Indoor Air},
  volume    = {2020},
  journal   = {Indoor Air},
  publisher = {John Wiley \& Sons Ltd},
  doi       = {10.1111/ina.12720},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200805-42072},
  pages     = {13},
  abstract  = {This study investigates the performance of two systems: personalized ventilation (PV) and ductless personalized ventilation (DPV). Even though the literature indicates a compelling performance of PV, it is not often used in practice due to its impracticality. Therefore, the present study assesses the possibility of replacing the inflexible PV with DPV in office rooms equipped with displacement ventilation (DV) in the summer season. Numerical simulations were utilized to evaluate the inhaled concentration of pollutants when PV and DPV are used. The systems were compared in a simulated office with two occupants: a susceptible occupant and a source occupant. Three types of pollution were simulated: exhaled infectious air, dermally emitted contamination, and room contamination from a passive source. Results indicated that PV improved the inhaled air quality regardless of the location of the pollution source; a higher PV supply flow rate positively impacted the inhaled air quality. Contrarily, the performance of DPV was highly sensitive to the source location and the personalized flow rate. A higher DPV flow rate tends to decrease the inhaled air quality due to increased mixing of pollutants in the room. Moreover, both systems achieved better results when the personalized system of the source occupant was switched off.},
  subject      = {Str{\"o}mungsmechanik},
  language  = {en}
}
@article{GenaVoelkerSettles,
  author    = {Gena, Amayu Wakoya and V{\"o}lker, Conrad and Settles, Gary},
  title     = {Qualitative and quantitative schlieren optical measurement of the human thermal plume},
  series = {Indoor Air},
  volume    = {2020},
  journal   = {Indoor Air},
  number    = {volume 30, issue 4},
  publisher = {John Wiley \& Sons},
  doi       = {10.1111/ina.12674},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200709-41936},
  pages     = {757 -- 766},
  abstract  = {A new large-field, high-sensitivity, single-mirror coincident schlieren optical instrument has been installed at the Bauhaus-Universit{\"a}t Weimar for the purpose of indoor air research. Its performance is assessed by the non-intrusive measurement of the thermal plume of a heated manikin. The schlieren system produces excellent qualitative images of the manikin's thermal plume and also quantitative data, especially schlieren velocimetry of the plume's velocity field that is derived from the digital cross-correlation analysis of a large time sequence of schlieren images. The quantitative results are compared with thermistor and hot-wire anemometer data obtained at discrete points in the plume. Good agreement is obtained, once the differences between path-averaged schlieren data and planar anemometry data are reconciled.},
  subject      = {Raumklima},
  language  = {en}
}
@unpublished{VogelVoelkerBodeetal.,
  author    = {Vogel, Albert and V{\"o}lker, Conrad and Bode, Matthias and Marx, Steffen},
  title     = {Messung und Simulation der Erw{\"a}rmung von erm{\"u}dungsbeanspruchten Betonprobek{\"o}rpern},
  series = {Bauphysik},
  volume    = {2020},
  journal   = {Bauphysik},
  number    = {Volume 42, Issue 2},
  publisher = {John Wiley and Sons},
  doi       = {10.25643/bauhaus-universitaet.4147},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200425-41471},
  pages     = {86 -- 93},
  abstract  = {Im vorliegenden Beitrag werden Messungen und Berechnungen vorgestellt, die die Temperaturentwicklung in Betonzylindern aufgrund zyklischer Beanspruchung genau beschreiben. Die Messungen wurden in einem Versuchsstand, die Berechnungen im FEM-Programm ANSYS durchgef{\"u}hrt. Mit Hilfe der Temperaturmessungen konnten die Simulationen f{\"u}r die Temperaturentwicklung der Betonzylinder mit der verwendeten Betonrezeptur validiert werden. Die Untersuchungen lassen den Schluss zu, dass bei zyklischer Probek{\"o}rperbelastung und der einhergehenden Probek{\"o}rperdehnung Energie dissipiert wird und diese maßgeblich f{\"u}r die Erw{\"a}rmung der Probe verantwortlich ist.},
  subject      = {zyklische Beanspruchung},
  language  = {de}
}
@unpublished{VogelBenzVoelker,
  author    = {Vogel, Albert and Benz, Alexander and V{\"o}lker, Conrad},
  title     = {Untersuchung des W{\"a}rme{\"u}bergangs von zyklisch beanspruchten Betonzylindern},
  volume    = {2020},
  number    = {Volume 42, Issue 3},
  publisher = {John Wiley and Sons},
  doi       = {10.25643/bauhaus-universitaet.4181},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200619-41813},
  pages     = {131 -- 138},
  abstract  = {Wiederkehrende Belastungen, wie sie beispielsweise an Br{\"u}cken oder Windenergieanlagen auftreten, k{\"o}nnen innerhalb der Nutzungsdauer solcher Bauwerke bis zu 1.000.000.000 Lastwechsel erreichen. Um das dadurch eintretende Erm{\"u}dungsverhalten von Beton zu untersuchen, werden diese zyklischen Beanspruchungen in mechanischen Versuchen mit Pr{\"u}fzylindern nachgestellt. Damit Versuche mit solch hohen Lastwechselzahlen in akzeptablen Zeitdauern durchgef{\"u}hrt werden k{\"o}nnen, wird die Belastungsfrequenz erh{\"o}ht. Als Folge dieser erh{\"o}hten Belas-tungsfrequenz erw{\"a}rmen sich allerdings die Betonprobek{\"o}rper, was zu einem fr{\"u}heren, unrealistischen Versagenszeitpunkt f{\"u}hren kann, weshalb die Erw{\"a}rmung begrenzt werden muss. Um die W{\"a}rmefreisetzung in der Probe zu untersuchen, wurden Versuche und Simulationen durchgef{\"u}hrt. Im Beitrag wird die analytische und messtechnische Analyse des W{\"a}rme{\"u}bergangs an erw{\"a}rmten Betonzylindern vorgestellt. Resultierend daraus wird eine M{\"o}glichkeit zur Reduktion der Erw{\"a}rmung an zyklisch beanspruchten Betonzylindern vorgestellt.},
  subject      = {Zyklische Beanspruchung},
  language  = {de}
}
@inproceedings{DokhanchiArnoldVogeletal.,
  author    = {Dokhanchi, Najmeh Sadat and Arnold, J{\"o}rg and Vogel, Albert and V{\"o}lker, Conrad},
  title     = {Acoustic Travel-Time Tomography: Optimal Positioning of Transceiver and Maximal Sound-Ray Coverage of the Room},
  series = {Fortschritte der Akustik - DAGA 2019},
  booktitle = {Fortschritte der Akustik - DAGA 2019},
  doi       = {10.25643/bauhaus-universitaet.3877},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190408-38778},
  pages     = {4},
  abstract  = {Acoustic travel-time tomography (ATOM) determines the distribution of the temperature in a propagation medium by measuring the travel-time of acoustic signals between transmitters and receivers. To employ ATOM for indoor climate measurements, the impulse responses have been measured in the climate chamber lab of the Bauhaus-University Weimar and compared with the theoretical results of its image source model (ISM). A challenging task is distinguishing the reflections of interest in the reflectogram when the sound rays have similar travel-times. This paper presents a numerical method to address this problem by finding optimal positions of transmitter and receiver, since they have a direct impact on the distribution of travel times. These optimal positions have the minimum number of simultaneous arrival time within a threshold level. Moreover, for the tomographic reconstruction, when some of the voxels remain empty of sound-rays, it leads to inaccurate determination of the air temperature within those voxels. Based on the presented numerical method, the number of empty tomographic voxels are minimized to ensure the best sound-ray coverage of the room. Subsequently, a spatial temperature distribution is estimated by simultaneous iterative reconstruction technique (SIRT). The experimental set-up in the climate chamber verifies the simulation results.},
  subject      = {Bauphysik},
  language  = {en}
}
@unpublished{BodeMarxVogeletal.,
  author    = {Bode, Matthias and Marx, Steffen and Vogel, Albert and V{\"o}lker, Conrad},
  title     = {Dissipationsenergie bei Erm{\"u}dungsversuchen an Betonprobek{\"o}rpern},
  volume    = {2019},
  doi       = {10.25643/bauhaus-universitaet.4493},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20211012-44938},
  pages     = {9},
  abstract  = {Aufgrund des visko-elastoplastischen Materialverhaltens von Beton wird Probek{\"o}rpern und Bauteilen infolge zyklischer Beanspruchungen Energie zugef{\"u}hrt. Die entsprechenden Energiegr{\"o}ßen werden durch Hysteresefl{\"a}chen der Spannungs-Dehnungslinien beschrieben. In der Literatur finden sich dabei unterschiedliche Ans{\"a}tze, wof{\"u}r diese Energie verwendet wird. Erste Untersuchungen zeigen, dass zumindest ein Teil dieser dissipierten Energie in thermische Energie umgewandelt wird. Mithilfe der in diesem Beitrag beschriebenen Methodik lassen sich diese Energiegr{\"o}ßen f{\"u}r jeden Lastwechsel eines Erm{\"u}dungsversuches schnell und zuverl{\"a}ssig bestimmen. Anschließend wurden mit dem implementierten Algorithmus die dissipierten Energien von insgesamt 27 zyklischen Versuchen ausgewertet. Analog zu der Dehnungsentwicklung und der Steifigkeitsdegradation weisen auch die Verl{\"a}ufe der dissipierten Energie {\"u}ber die Lastwechselzahl einen dreiphasigen Verlauf auf. Die Auswertung zeigt außerdem eine Korrelation zwischen der Bruchlastwechselzahl und der dissipierten Energie. Auch der Zusammenhang zwischen Probek{\"o}rpererw{\"a}rmung und dissipierter Energie konnte best{\"a}tigt werden.},
  subject      = {Erm{\"u}dung},
  language  = {de}
}
@article{BenzTarabenLichtenheldetal.,
  author    = {Benz, Alexander and Taraben, Jakob and Lichtenheld, Thomas and Morgenthal, Guido and V{\"o}lker, Conrad},
  title     = {Thermisch-energetische Geb{\"a}udesimulation auf Basis eines Bauwerksinformationsmodells},
  series = {Bauphysik},
  journal   = {Bauphysik},
  number    = {40, Heft 2},
  doi       = {10.25643/bauhaus-universitaet.3835},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20181221-38354},
  pages     = {61 -- 67},
  abstract  = {F{\"u}r eine Absch{\"a}tzung des Heizw{\"a}rmebedarfs von Geb{\"a}uden und Quartieren k{\"o}nnen thermisch-energetische Simulationen eingesetzt werden. Grundlage dieser Simulationen sind geometrische und physikalische Geb{\"a}udemodelle. Die Erstellung des geometrischen Modells erfolgt in der Regel auf Basis von Baupl{\"a}nen oder Vor-Ort-Begehungen, was mit einem großen Recherche- und Modellierungsaufwand verbunden ist. Sp{\"a}tere bauliche Ver{\"a}nderungen des Geb{\"a}udes m{\"u}ssen h{\"a}ufig manuell in das Modell eingearbeitet werden, was den Arbeitsaufwand zus{\"a}tzlich erh{\"o}ht. Das physikalische Modell stellt die Menge an Parametern und Randbedingungen dar, welche durch Materialeigenschaften, Lage und Umgebungs-einfl{\"u}sse gegeben sind. Die Verkn{\"u}pfung beider Modelle wird innerhalb der entsprechenden Simulations-software realisiert und ist meist nicht in andere Softwareprodukte {\"u}berf{\"u}hrbar. Mithilfe des Building Information Modeling (BIM) k{\"o}nnen Simulationsdaten sowohl konsistent gespeichert als auch {\"u}ber Schnittstellen mit entsprechenden Anwendungen ausgetauscht werden. Hierf{\"u}r wird eine Methode vorgestellt, die thermisch-energetische Simulationen auf Basis des standardisierten {\"U}bergabe-formats Industry Foundation Classes (IFC) inklusive anschließender Auswertungen erm{\"o}glicht. Dabei werden geometrische und physikalische Parameter direkt aus einem {\"u}ber den gesamten Lebenszyklus aktuellen Geb{\"a}udemodell extrahiert und an die Simulation {\"u}bergeben. Dies beschleunigt den Simulations-prozess hinsichtlich der Geb{\"a}udemodellierung und nach sp{\"a}teren baulichen Ver{\"a}nderungen. Die erarbeite-te Methode beruht hierbei auf einfachen Modellierungskonventionen bei der Erstellung des Bauwerksinformationsmodells und stellt eine vollst{\"a}ndige {\"U}bertragbarkeit der Eingangs- und Ausgangswerte sicher. Thermal building simulation based on BIM-models. Thermal energetic simulations are used for the estimation of the heating demand of buildings and districts. These simulations are based on building models containing geometrical and physical information. The creation of geometrical models is usually based on existing construction plans or in situ assessments which demand a comparatively big effort of investigation and modeling. Alterations, which are later applied to the structure, request manual changes of the related model, which increases the effort additionally. The physical model represents the total amount of parameters and boundary conditions that are influenced by material properties, location and environmental influences on the building. The link between both models is realized within the correspondent simulation soft-ware and is usually not transferable to other software products. By Applying Building Information Modeling (BIM) simulation data is stored consistently and an exchange to other software is enabled. Therefore, a method which allows a thermal energetic simulation based on the exchange format Industry Foundation Classes (IFC) including an evaluation is presented. All geometrical and physical information are extracted directly from the building model that is kept up-to-date during its life cycle and transferred to the simulation. This accelerates the simulation process regarding the geometrical modeling and adjustments after later changes of the building. The developed method is based on simple conventions for the creation of the building model and ensures a complete transfer of all simulation data.},
  subject      = {Building Information Modeling},
  language  = {de}
}
@article{BenzTarabenLichtenheldetal.,
  author    = {Benz, Alexander and Taraben, Jakob and Lichtenheld, Thomas and Morgenthal, Guido and V{\"o}lker, Conrad},
  title     = {Thermisch-energetische Geb{\"a}udesimulation auf Basis eines Bauwerksinformationsmodells},
  series = {Bauphysik},
  journal   = {Bauphysik},
  number    = {40, Heft 2},
  doi       = {10.25643/bauhaus-universitaet.3819},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20181102-38190},
  pages     = {61 -- 67},
  abstract  = {F{\"u}r eine Absch{\"a}tzung des Heizw{\"a}rmebedarfs von Geb{\"a}uden und Quartieren k{\"o}nnen thermisch-energetische Simulationen eingesetzt werden. Grundlage dieser Simulationen sind geometrische und physikalische Geb{\"a}udemodelle. Die Erstellung des geometrischen Modells erfolgt in der Regel auf Basis von Baupl{\"a}nen oder Vor-Ort-Begehungen, was mit einem großen Recherche- und Modellierungsaufwand verbunden ist. Sp{\"a}tere bauliche Ver{\"a}nderungen des Geb{\"a}udes m{\"u}ssen h{\"a}ufig manuell in das Modell eingearbeitet werden, was den Arbeitsaufwand zus{\"a}tzlich erh{\"o}ht. Das physikalische Modell stellt die Menge an Parametern und Randbedingungen dar, welche durch Materialeigenschaften, Lage und Umgebungs-einfl{\"u}sse gegeben sind. Die Verkn{\"u}pfung beider Modelle wird innerhalb der entsprechenden Simulations-software realisiert und ist meist nicht in andere Softwareprodukte {\"u}berf{\"u}hrbar. Mithilfe des Building Information Modeling (BIM) k{\"o}nnen Simulationsdaten sowohl konsistent gespeichert als auch {\"u}ber Schnittstellen mit entsprechenden Anwendungen ausgetauscht werden. Hierf{\"u}r wird eine Methode vorgestellt, die thermisch-energetische Simulationen auf Basis des standardisierten {\"U}bergabe-formats Industry Foundation Classes (IFC) inklusive anschließender Auswertungen erm{\"o}glicht. Dabei werden geometrische und physikalische Parameter direkt aus einem {\"u}ber den gesamten Lebenszyklus aktuellen Geb{\"a}udemodell extrahiert und an die Simulation {\"u}bergeben. Dies beschleunigt den Simulations-prozess hinsichtlich der Geb{\"a}udemodellierung und nach sp{\"a}teren baulichen Ver{\"a}nderungen. Die erarbeite-te Methode beruht hierbei auf einfachen Modellierungskonventionen bei der Erstellung des Bauwerksinformationsmodells und stellt eine vollst{\"a}ndige {\"U}bertragbarkeit der Eingangs- und Ausgangswerte sicher. Thermal building simulation based on BIM-models. Thermal energetic simulations are used for the estimation of the heating demand of buildings and districts. These simulations are based on building models containing geometrical and physical information. The creation of geometrical models is usually based on existing construction plans or in situ assessments which demand a comparatively big effort of investigation and modeling. Alterations, which are later applied to the structure, request manual changes of the related model, which increases the effort additionally. The physical model represents the total amount of parameters and boundary conditions that are influenced by material properties, location and environmental influences on the building. The link between both models is realized within the correspondent simulation soft-ware and is usually not transferable to other software products. By Applying Building Information Modeling (BIM) simulation data is stored consistently and an exchange to other software is enabled. Therefore, a method which allows a thermal energetic simulation based on the exchange format Industry Foundation Classes (IFC) including an evaluation is presented. All geometrical and physical information are extracted directly from the building model that is kept up-to-date during its life cycle and transferred to the simulation. This accelerates the simulation process regarding the geometrical modeling and adjustments after later changes of the building. The developed method is based on simple conventions for the creation of the building model and ensures a complete transfer of all simulation data.},
  subject      = {Geb{\"a}udeh{\"u}lle},
  language  = {de}
}
@article{AlsaadVoelker,
  author    = {Alsaad, Hayder and V{\"o}lker, Conrad},
  title     = {Performance assessment of a ductless personalized ventilation system using a validated CFD model},
  series = {Journal of Building Performance Simulation},
  volume    = {2018},
  journal   = {Journal of Building Performance Simulation},
  number    = {11, Heft 6},
  doi       = {10.25643/bauhaus-universitaet.3850},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190218-38500},
  pages     = {689 -- 704},
  abstract  = {The aim of this study is twofold: to validate a computational fluid dynamics (CFD) model, and then to use the validated model to evaluate the performance of a ductless personalized ventilation (DPV) system. To validate the numerical model, a series of measurements was conducted in a climate chamber equipped with a thermal manikin. Various turbulence models, settings, and options were tested; simulation results were compared to the measured data to determine the turbulence model and solver settings that achieve the best agreement between the measured and simulated values. Subsequently, the validated CFD model was then used to evaluate the thermal environment and indoor air quality in a room equipped with a DPV system combined with displacement ventilation. Results from the numerical model were then used to quantify thermal sensation and comfort using the UC Berkeley thermal comfort model.},
  subject      = {Ventilation},
  language  = {en}
}
@article{VoelkerAlsaad,
  author    = {V{\"o}lker, Conrad and Alsaad, Hayder},
  title     = {Simulating the human body's microclimate using automatic coupling of CFD and an advanced thermoregulation model},
  series = {Indoor Air},
  volume    = {2018},
  journal   = {Indoor Air},
  number    = {28, Heft 3},
  doi       = {10.25643/bauhaus-universitaet.3851},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190218-38517},
  pages     = {415 -- 425},
  abstract  = {This study aims to develop an approach to couple a computational fluid dynamics (CFD) solver to the University of California, Berkeley (UCB) thermal comfort model to accurately evaluate thermal comfort. The coupling was made using an iterative JavaScript to automatically transfer data for each individual segment of the human body back and forth between the CFD solver and the UCB model until reaching convergence defined by a stopping criterion. The location from which data are transferred to the UCB model was determined using a new approach based on the temperature difference between subsequent points on the temperature profile curve in the vicinity of the body surface. This approach was used because the microclimate surrounding the human body differs in thickness depending on the body segment and the surrounding environment. To accurately simulate the thermal environment, the numerical model was validated beforehand using experimental data collected in a climate chamber equipped with a thermal manikin. Furthermore, an example of the practical implementations of this coupling is reported in this paper through radiant floor cooling simulation cases, in which overall and local thermal sensation and comfort were investigated using the coupled UCB model.},
  subject      = {Numerische Str{\"o}mungssimulation},
  language  = {en}
}
@article{VoelkerMaempelKornadt,
  author    = {V{\"o}lker, Conrad and M{\"a}mpel, Silvio and Kornadt, Oliver},
  title     = {Measuring the human body's micro-climate using a thermal manikin},
  series = {Indoor Air},
  journal   = {Indoor Air},
  number    = {24, 6},
  doi       = {10.25643/bauhaus-universitaet.3815},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20181025-38153},
  pages     = {567 -- 579},
  abstract  = {The human body is surrounded by a micro-climate which results from its convective release of heat. In this study, the air temperature and flow velocity of this micro-climate were measured in a climate chamber at various room temperatures, using a thermal manikin simulating the heat release of the human being. Different techniques (Particle Streak Tracking, thermography, anemometry, and thermistors) were used for measurement and visualization. The manikin surface temperature was adjusted to the particular indoor climate based on simulations with a thermoregulation model (UCBerkeley Thermal Comfort Model). We found that generally, the micro-climate is thinner at the lower part of the torso, but expands going up. At the head, there is a relatively thick thermal layer, which results in an ascending plume above the head. However, the micro-climate shape strongly depends not only on the body segment, but also on boundary conditions: the higher the temperature difference between the surface temperature of the manikin and the air temperature, the faster the air flow in the micro-climate. Finally, convective heat transfer coefficients strongly increase with falling room temperature, while radiative heat transfer coefficients decrease. The type of body segment strongly influences the convective heat transfer coefficient, while only minimally influencing the radiative heat transfer coefficient.},
  subject      = {Raumklima},
  language  = {en}
}
@article{VoelkerBeckmannKoehlmannetal.,
  author    = {V{\"o}lker, Conrad and Beckmann, Julia and Koehlmann, Sandra and Kornadt, Oliver},
  title     = {Occupant requirements in residential buildings - an empirical study and a theoretical model},
  series = {Advances in Building Energy Research},
  journal   = {Advances in Building Energy Research},
  number    = {7 (1)},
  doi       = {10.25643/bauhaus-universitaet.3813},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20181015-38137},
  pages     = {35 -- 50},
  abstract  = {Occupant needs with regard to residential buildings are not well known due to a lack of representative scientific studies. To improve the lack of data, a large scale study was carried out using a Post Occupancy Evaluation of 1,416 building occupants. Several criteria describing the needs of occupants were evaluated with regard to their subjective level of relevance. Additionally, we investigated the degree to which deficiencies subjectively exist, and the degree to which occupants were able to accept them. From the data obtained, a hierarchy of criteria was created. It was found that building occupants ranked the physiological needs of air quality and thermal comfort the highest. Health hazards such as mould and contaminated building materials were unacceptable for occupants, while other deficiencies were more likely to be tolerated. Occupant satisfaction was also investigated. We found that most occupants can be classified as satisfied, although some differences do exist between different populations. To explain the relationship between the constructs of what we call relevance, acceptance, deficiency and satisfaction, we then created an explanatory model. Using correlation and regression analysis, the validity of the model was then confirmed by applying the collected data. The results of the study are both relevant in shaping further research and in providing guidance on how to maximize tenant satisfaction in real estate management.},
  subject      = {Post Occupancy Evaluation},
  language  = {en}
}
@techreport{VogelVoelkerArnoldetal.,
  author    = {Vogel, Albert and V{\"o}lker, Conrad and Arnold, J{\"o}rg and Schmidt, Jens and Thurow, Torsten and Braunes, J{\"o}rg and Tonn, Christian and Bode, Kay-Andr{\´e} and Baldy, Franziska and Erfurt, Wolfgang and Tatarin, Ren{\´e}},
  title     = {Methoden und Baustoffe zur nutzerorientierten Bausanierung. Schlussbericht zum InnoProfile Forschungsvorhaben},
  organization    = {Bauhaus-Universit{\"a}t Weimar},
  isbn      = {978-3-86068-501-3 (Printausg.)},
  doi       = {10.25643/bauhaus-universitaet.2022},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20130830-20229},
  pages     = {106},
  abstract  = {Nutzerorientierte Bausanierung bedeutet eine gegen{\"u}ber dem konventionellen Vorgehen deutlich verst{\"a}rkte Ausrichtung des Planungs- und Sanierungsprozesses auf die Anforderungen und Bed{\"u}rfnisse des zuk{\"u}nftigen Nutzers eines Geb{\"a}udes. Dies hat einerseits ein hochwertigeres Produkt zum Ergebnis, erfordert andererseits aber auch den Einsatz neuer Methoden und Baustoffe sowie ein vernetztes Zusammenarbeiten aller am Bauprozess Beteiligten. Der Fokus der Publikation liegt dabei auf den Bereichen, die eine hohe Relevanz f{\"u}r die nutzerorientierte Bausanierung aufweisen. Dabei handelt es sich insbesondere um: Computergest{\"u}tztes Bauaufmaß und digitale Bauwerksmodellierung (BIM), bauphysikalische Methoden zur Optimierung von Energieeffizienz und Behaglichkeit bei der Sanierung von Bestandsgeb{\"a}uden, zerst{\"o}rungsfreie Untersuchungsmethoden im Rahmen einer substanzschonenden Bauzustandsanalyse und Entwicklung von Erg{\"a}nzungsbaustoffen. Das Projekt nuBau ist eine Kooperation zwischen den Fakult{\"a}ten Bauingenieurwesen und Architektur der Bauhaus-Universit{\"a}t Weimar. Die beteiligten Professuren sind: Bauphysik, Informatik in der Architektur, Polymere Werkstoffe und Werkstoffe des Bauens.},
  subject      = {Nutzerorientierte Bausanierung},
  language  = {de}
}
@article{VoelkerKornadtOstry,
  author    = {V{\"o}lker, Conrad and Kornadt, Oliver and Ostry, Milan},
  title     = {Temperature reduction due to the application of phase change materials},
  series = {Energy and Buildings},
  journal   = {Energy and Buildings},
  number    = {40, 5},
  doi       = {10.25643/bauhaus-universitaet.3816},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20181025-38166},
  pages     = {937 -- 944},
  abstract  = {Overheating is a major problem in many modern buildings due to the utilization of lightweight constructions with low heat storing capacity. A possible answer to this problem is the emplacement of phase change materials (PCM), thereby increasing the thermal mass of a building. These materials change their state of aggregation within a defined temperature range. Useful PCM for buildings show a phase transition from solid to liquid and vice versa. The thermal mass of the materials is increased by the latent heat. A modified gypsum plaster and a salt mixture were chosen as two materials for the study of their impact on room temperature reduction. For realistic investigations, test rooms were erected where measurements were carried out under different conditions such as temporary air change, alternate internal heat gains or clouding. The experimental data was finally reproduced by dint of a mathematical model.},
  subject      = {Raumklima},
  language  = {en}
}
@misc{Voelker2005,
  type      = {Master Thesis},
  author    = {V{\"o}lker, Conrad},
  title     = {Untersuchungen hinsichtlich des Einflusses von PCM auf die Raumlufttemperatur},
  doi       = {10.25643/bauhaus-universitaet.663},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-6639},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  year      = {2005},
  abstract  = {Das Ziel der vorliegenden Diplomarbeit war es, „Untersuchungen hinsichtlich des Einflusses von Phase Change Materials auf die Raumlufttemperatur" durchzuf{\"u}hren und anschließend die Ergebnisse auszuwerten. Dabei galt es, thermodynamische Grundlagen zu erl{\"a}utern sowie den derzeitigen Stand der Forschung darzulegen. Dies wurde umfassend bearbeitet, allerdings kann hierbei aufgrund des Umfangs und der Vielfalt im Bereich der internationalen PCM-Forschung kein Anspruch auf Vollst{\"a}ndigkeit erhoben werden. Ein Hauptteil dieser Arbeit bestand darin, den Versuchsaufbau der Referenzr{\"a}ume im Eiermann-Bau in Apolda als Grundlage f{\"u}r sp{\"a}tere Messungen detailliert zu beschreiben. Dabei wurde auf die gesamte Messanlage, die eingebrachten PCM sowie auf daraus resultierende physikalische Kenngr{\"o}ßen ausf{\"u}hrlich eingegangen. Es galt, geometrische, chemische und physikalische Einfl{\"u}sse einzusch{\"a}tzen, aber auch Schwachstellen aufzudecken, um die sp{\"a}ter folgenden Messreihen exakt auswerten zu k{\"o}nnen. Als kritisch einzusch{\"a}tzende Gr{\"o}ße fiel dabei besonders das eingebrachte Salzgemisch auf, welches hinsichtlich des Schmelz- und Kristallisationsbereiches als kaum beurteilbar auffiel. Dies konnte auch nach mehreren Untersuchungen, hier ist insbesondere die dynamische Differenzkalorimetrie zu nennen, nicht hinreichend gekl{\"a}rt werden. Basierend auf diesen Erkenntnissen wurden vergleichende Messreihen durchgef{\"u}hrt, welche durch verschiedene Luftwechselraten gestaltet wurden. Im Maximum konnte dabei im PCM-konditionierten Raum eine Reduktion der Temperatur um 6 K erreicht werden. Dabei muss allerdings ber{\"u}cksichtigt werden, dass diese Differenz gr{\"o}ßtenteils auf die thermische Masse des Salzgemischs zur{\"u}ckgef{\"u}hrt werden kann. Eine abschließende Messung ohne Salzgemisch zeigte, dass aufgrund des latenten W{\"a}rmespeicherverm{\"o}gens des PCM-Putzes lediglich eine thermische Differenz von 2 K erreicht werden kann. Hinsichtlich der Luftwechselrate ist anzumerken, dass die erwartete, vergleichsweise z{\"u}gige Ausk{\"u}hlung trotz L{\"u}ftung in der Praxis nicht nachvollzogen werden konnte. Zur Auswertung der gewonnenen Messwerte galt es, das am Lehrstuhl Bauphysik vorhandene mathematische Minimalmodell auf die am Objekt vorhandenen Randbedingungen anzupassen. Aus den Datenwolken der Atmosph{\"a}rentemperatur sowie der Globalstrahlung mussten Funktionen approximiert werden, da diese {\"a}ußeren Zw{\"a}nge einen entscheidenden Einfluss auf den Verlauf der Innenraumtemperatur aus{\"u}ben. Die Ergebnisse der Berechungen des Temperaturverlaufs k{\"o}nnen als zufrieden stellend betrachtet werden, jedoch wurde deutlich, dass ein genaues Nachstellen nicht m{\"o}glich ist. Dies ist vor allem auf die Tatsache zur{\"u}ckzuf{\"u}hren, dass das Minimalmodell lediglich eine Beschreibung der wesentlichen Prozesse mathematisch abbildet. Eine kritische Auseinandersetzung hinsichtlich allgemeiner Standpunkte als auch der Anwendbarkeit auf die Referenzr{\"a}ume wurde abschließend diskutiert.},
  subject      = {Latentw{\"a}rmespeicher},
  language  = {de}
}