@article{JentschKulleBodeetal.,
  author    = {Jentsch, Mark F. and Kulle, Christoph and Bode, Tobias and Pauer, Toni and Osburg, Andrea and Namgyel, Karma and Euthra, Karma and Dukjey, Jamyang and Tenzin, Karma},
  title     = {Field study of the building physics properties of common building types in the Inner Himalayan valleys of Bhutan},
  series = {Energy for Sustainable Development 38},
  journal   = {Energy for Sustainable Development 38},
  doi       = {10.25643/bauhaus-universitaet.3139},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170419-31393},
  pages     = {48 -- 66},
  abstract  = {Traditionally, buildings in the Inner Himalayan valleys of Bhutan were constructed from rammed earth in the western regions and quarry stone in the central and eastern regions. Whilst basic architectural design elements have been retained, the construction methods have however changed over recent decades alongside expectations for indoor thermal comfort. Nevertheless, despite the need for space heating, thermal building performance remains largely unknown. Furthermore, no dedicated climate data is available for building performance assessments. This paper establishes such climatological information for the capital Thimphu and presents an investigation of building physics properties of traditional and contemporary building types. In a one month field study 10 buildings were surveyed, looking at building air tightness, indoor climate, wall U-values and water absorption of typical wall construction materials. The findings highlight comparably high wall U-values of 1.0 to 1.5 W/m²K for both current and historic constructions. Furthermore, air tightness tests show that, due to poorly sealed joints between construction elements, windows and doors, many buildings have high infiltration rates, reaching up to 5 air changes per hour. However, the results also indicate an indoor climate moderating effect of more traditional earth construction techniques. Based on these survey findings basic improvements are being suggested.},
  subject      = {Luftdichtheit},
  language  = {en}
}
@misc{Jahn,
  type      = {Master Thesis},
  author    = {Jahn, Rosa},
  title     = {Evaluation von Nutzerbed{\"u}rfnissen in Wohngeb{\"a}uden unter Ber{\"u}cksichtigung hygrothermischer Messdaten},
  doi       = {10.25643/bauhaus-universitaet.1875},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20130320-18758},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  abstract  = {Evaluation von Nutzerbed{\"u}rfnissen in Wohngeb{\"a}uden unter Ber{\"u}cksichtigung hygrothermischer Messdaten},
  subject      = {Raumklima},
  language  = {de}
}
@phdthesis{Holeck2008,
  author    = {Holeck, Stefan},
  title     = {Energieoptimierung in Krankenh{\"a}usern Qualit{\"a}t und Quantit{\"a}t des Energiebedarfs von Krankenh{\"a}usern unter besonderer Ber{\"u}cksichtigung des Einflusses des architektonischen und baukonstruktiven Entwurfes},
  doi       = {10.25643/bauhaus-universitaet.1224},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20080207-12913},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  year      = {2008},
  abstract  = {Krankenh{\"a}user sind heute {\"a}ußerst komplexe Objekte, in denen komplizierte funktionale Anforderungen zusammen stoßen, die nur mit Hilfe einer sehr intensiven technischen Ausstattung zufrieden stellend gel{\"o}st werden k{\"o}nnen. Sie sind durch die medizintechnische Ausr{\"u}stung, die zum Teil sehr hohen hygienischen Anforderungen, die Patientenanspr{\"u}che sowie die sch{\"a}rferen wirtschaftlichen Bedingungen gekennzeichnet. Gleichzeitig haben Krankenh{\"a}user einen sehr hohen Energieverbrauch, der ein großes Einsparpotenzial beinhaltet, das vor dem Hintergrund der schlechteren Verf{\"u}gbarkeit und der {\"o}kologischen Probleme des CO2-Ausstoßes durch die Verbrennung fossiler Brennstoffe sowie der Notwendigkeit einer gesicherten Energieversorgung eine zunehmende Bedeutung hat. Die energetische Struktur eines Geb{\"a}udes wird entscheidend in den fr{\"u}hen projekt- und Entwurfsphasen f{\"u}r die gesamte Lebensdauer des Geb{\"a}udes festgelegt. Der Architekt und andere Entscheider ben{\"o}tigen daher Instrumente, um diese Struktur einfach bestimmen und beurteilen zu k{\"o}nnen. Hierf{\"u}r ist eine energetische Analyse und die Definition des Einflusspotenzials des architektonischen und baukonstruktiven Entwurfes auf den Energieverbrauch notwendig. Darauf aufbauend werden spezifische fl{\"a}chenbezogene Energieaufwandszahlen gebildet, wodurch eine energetische Beurteilung unabh{\"a}ngig von konkreten Entw{\"u}rfen m{\"o}glich wird. Durch die Definition von optimalen energetischen Strukturen einzelner Referenzbereiche von Krankenh{\"a}usern wird ein Maßstab geschaffen, an dem die tats{\"a}chlichen Entw{\"u}rfe gemessen werden k{\"o}nnen, um daraus dimensionslose fl{\"a}chenbezogene Energieaufwandszahlen bilden zu k{\"o}nnen. Diese stellen Kennzahlen f{\"u}r die energetische Struktur von Entw{\"u}rfen dar, wodurch eine Vergleichbarkeit sowohl bei einzelnen Bereichen des Krankenhauses wie auch beim gesamten Geb{\"a}ude hergestellt wird. Energetisch vorteilhafter ist eine fl{\"a}chige Geb{\"a}udestruktur mit einer direkten Zuordnung der Technikzentralen zu den angeschlossenen Versorgungsbereichen. Die Schaffung von optimierten Installationsbedingungen erm{\"o}glicht eine energieoptimierte Struktur der Technischen Ausr{\"u}stung und ist beim Entwurf zu ber{\"u}cksichtigen.},
  subject      = {Frankfurt <Main> / Dezernat Umwelt},
  language  = {de}
}
@misc{Rothe2005,
  type      = {Master Thesis},
  author    = {Rothe, Christian},
  title     = {Untersuchung diffuser koh{\"a}renter Schallfelder in Atrien},
  doi       = {10.25643/bauhaus-universitaet.678},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-6786},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  year      = {2005},
  abstract  = {In dieser Diplomarbeit werden - anhand eines Simulationsprogrammes - die diffusen Schallfelder in Atrien untersucht. Diesbez{\"u}glich standen Referenzobjekte in Berlin zur Verf{\"u}gung. Es wurde untersucht, inwieweit sich die Raumgeometrie, die Volumina und die Absorptionseigenschaften der Umh{\"u}llungsfl{\"a}chen auf die Energieverteilung im Atriumsraum auswirken. Ziel der Arbeit ist es, Optimierungspotenziale aufzuzeigen und L{\"o}sungsvorschl{\"a}ge zu entwickeln, die zeigen, mit welchen Mitteln und Methoden die Raumakustik nachtr{\"a}glich verbessert werden kann.},
  subject      = {Absorption},
  language  = {de}
}
@phdthesis{Kuhne1998,
  author    = {Kuhne, Michael},
  title     = {Modellierung des Energietransports durch Verglasungen},
  doi       = {10.25643/bauhaus-universitaet.43},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20040220-458},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  year      = {1998},
  abstract  = {Es werden sowohl analytische als auch numerische Verfahren zur Berechnung der W{\"a}rmeverluste von Verglasungen vorgestellt, wobei alle am Energietransport beteiligten Prozesse, die W{\"a}rmeleitung, die thermisch getriebenen Konvektionsstr{\"o}mungen und die infrarote Strahlungswechselwirkung, korrekt und vollst{\"a}ndig ber{\"u}cksichtigt werden. Mit Hilfe numerischer Str{\"o}mungssimulation werden Verglasungen systematisch hinsichtlich der F{\"u}llgasart, der Infrarotverspiegelung, der Einbaulage und des Scheibenabstandes sowie der Anzahl der Gaszwischenr{\"a}ume (Zwei-, Drei- und Vierscheiben-Verglasung) untersucht und verglichen. Die Abh{\"a}ngigkeit des k-Wertes von den Temperaturen der angrenzenden Klimate (Atmosph{\"a}re und Innenraum) wird dargestellt.},
  subject      = {Verglasung},
  language  = {de}
}
@article{SalandinArnoldKornadt,
  author    = {Salandin, Andrea and Arnold, J{\"o}rg and Kornadt, Oliver},
  title     = {Noise in an intensive care unit},
  series = {The Journal of the Acoustical Society of America},
  volume    = {2011},
  journal   = {The Journal of the Acoustical Society of America},
  number    = {130 (6)},
  doi       = {10.25643/bauhaus-universitaet.3264},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170713-32649},
  pages     = {3754 -- 3760},
  abstract  = {Patients and staff in hospitals are exposed to a complex sound environment with rather high noise levels. In intensive care units, the main noise sources are hospital staff on duty and medical equipment, which generates both operating noise and acoustic alarms. Although noise in most cases is produced during activities for the purpose of saving life, noise can induce significant changes in the depth and quality of sleep and negatively affect health in general. Results of a survey of hospital staff are presented as well as measurements in two German hospital wards: a standard two-bed room and a special Intermediate Care Unit (IMC-Unit), each in a different Intensive Care Unit (ICU). Sound pressure data were collected over a 48 hour period and converted into different levels (LAFeq, LAFmax, LAFmin, LAF 5\%), as well as a rating level LAr, which is used to take tonality and impulsiveness into account. An analysis of the survey and the measured data, together with a comparison of thresholds of national and international regulations and standards describe the acoustic situation and its likely noise effects on staff and patients.},
  subject      = {L{\"a}rm},
  language  = {en}
}
@inproceedings{Dokhanchi,
  author    = {Dokhanchi, Najmeh Sadat},
  title     = {Acoustic travel time tomography: Applicability of an array of directional sound sources},
  editor    = {Arnold, J{\"o}rg},
  doi       = {10.25643/bauhaus-universitaet.4658},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220622-46589},
  abstract  = {The technique of Acoustic travel-time TOMography (ATOM) allows for measuring the distribution of air temperatures throughout the entire room based on the determined sound-travel-times of early reflections, currently up to second order reflections. The number of detected early reflections in the room impulse response (RIR) which stands for the desired sound paths inside the room, has a significant impact on the resolution of reconstructed temperatures. This study investigates the possibility of utilizing an array of directional sound sources for ATOM measurements instead of a single omnidirectional loudspeaker used in the previous studies [1-3]. The developed measurement setup consists of two directional sound sources placed near the edge of the floor in the climate chamber of the Bauhaus-University Weimar and one omnidirectional receiver at center of the room near the ceiling. In order to compensate for the reduced number of sound paths when using directional sound sources, it is proposed to take high-energy early reflections up to third order into account. For this purpose, the simulated travel times up to third-order image sources were implemented in the image source model (ISM) algorithm, by which these early reflections can be detected effectively for air temperature reconstructions. To minimize the uncertainties of travel-times estimation due to the positioning of the sound transducers inside the room, measurements were conducted to determine the exact emitting point of the utilized sound source i.e. its acoustic center (AC). For these measurements, three types of excitation signals (MLS, linear and logarithmic chirp signals) with various frequency ranges were used considering that the acoustic center of a sound source is a frequency dependent parameter [4]. Furthermore, measurements were conducted to determine an optimum excitation signal based on the given condition of the ATOM measurement set-up which defines an optimum method for the RIR estimation correspondingly. Finally, the uncertainty of the measuring system utilizing an array of directional sound sources was analyzed.},
  subject      = {Bauphysik},
  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}
}
@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}
}
@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}
}
@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}
}
@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{Jentsch,
  author    = {Jentsch, Mark F.},
  title     = {Entwicklung eines Sommerreferenzjahres zur Bestimmung der sommerlichen {\"U}berhitzung von Geb{\"a}uden},
  series = {Bauphysiktage Kaiserslautern 2015, Kaiserslautern, 21-22 Oktober 2015},
  booktitle = {Bauphysiktage Kaiserslautern 2015, Kaiserslautern, 21-22 Oktober 2015},
  editor    = {Kornadt, Oliver},
  publisher = {Eigenverlag der Technischen Universit{\"a}t Kaiserslautern},
  address   = {Kaiserslautern},
  doi       = {10.25643/bauhaus-universitaet.3105},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170516-31058},
  pages     = {53-61},
  abstract  = {Die Ableitung von sommer-fokussierten warmen Referenzjahren aus langj{\"a}hrigen Klimadaten erfolgt in Europa bisher nach unterschiedlichen, l{\"a}nderspezifischen Methoden, die sich in der Regel allein auf die Trockentemperatur beziehen und in der Auswahl eines zusammenh{\"a}ngenden realen Sommerhalbjahres resultieren. Simulationsergebnisse zur sommerlichen {\"U}berhitzung von nat{\"u}rlich bel{\"u}fteten Geb{\"a}uden in Deutschland und Großbritannien zeigen jedoch f{\"u}r einige Wetterstationen weniger {\"U}berhitzung f{\"u}r Simulationen mit dem sommer-fokussierten Referenzjahr als f{\"u}r solche mit dem entsprechenden Testreferenzjahr (TRY) f{\"u}r den gleichen Ort. Dies gilt insbesondere dann, wenn einzelne Monate miteinander verglichen werden. Neben der Wahl eines kompletten Halbjahres, das sowohl extrem warme als auch vergleichsweise k{\"u}hle Monate beinhalten kann, liegt dies vor allem begr{\"u}ndet in der fehlenden Ber{\"u}cksichtigung der Solarstrahlung bei der Auswahl eines warmen Referenzjahres, die jedoch eine wichtige Rolle f{\"u}r sommerliche {\"U}berhitzungserscheinungen in Geb{\"a}uden spielt. Eine verl{\"a}ssliche, allgemein anerkannte Methode zur Erstellung von sommer-fokussierten Referenzjahren erscheint daher auch im Hinblick auf die rechtlichen Rahmenbedingungen in der Europ{\"a}ischen Union, die Strategien zur nat{\"u}rlichen Bel{\"u}ftung von Neubauten und Sanierungen beg{\"u}nstigen, erforderlich. Diese Arbeit pr{\"a}sentiert einen Ansatz zur Erstellung eines Sommerreferenzjahres (Summer Reference Year - SRY) aus dem TRY eines gegebenen Ortes und langj{\"a}hrigen Klimadaten. Die existierenden TRY-Daten werden hierbei skaliert, um den Bedingungen f{\"u}r Trockentemperatur und Solarstrahlung von nah-extremen Kandidatenjahren zu entsprechen, die separat {\"u}ber einen statistischen Ansatz ausgew{\"a}hlt werden. Anschließend werden Feuchttemperatur, Windgeschwindigkeit und Luftdruck des TRY durch lineare Korrelationen mit der Trockentemperatur angepasst, um die entsprechenden SRY-Daten zu erhalten. Der Vorteil dieser Methode liegt darin, dass das grundlegende Wettermuster des TRY erhalten bleibt und somit eine klare Relation zwischen SRY und TRY besteht, die eine Vergleichbarkeit von Simulationsergebnissen gew{\"a}hrleistet. {\"U}ber vergleichende Geb{\"a}udesimulationen mit dem zugrundeliegenden TRY und langj{\"a}hrigen Klimadatens{\"a}tzen kann nachgewiesen werden, dass sich das SRY zur Ermittlung sommerlicher {\"U}berhitzungserscheinungen in nat{\"u}rlich bel{\"u}fteten Geb{\"a}uden eignet. Weiterhin kann gezeigt werden, dass das SRY im Gegensatz zur direkten Nutzung eines Kandidatenjahres f{\"u}r einen nah-extremen Sommer die M{\"o}glichkeit eines monatsscharfen Vergleichs mit dem TRY erlaubt und frei von wenig repr{\"a}sentativen Besonderheiten ist, die in den entsprechenden Kandidatenjahren vorhanden sein k{\"o}nnen.},
  subject      = {Bauphysik},
  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}
}
@phdthesis{Laar2002,
  author    = {Laar, Michael},
  title     = {Untersuchung zur Tageslichtnutzung in den feucht-heißen Tropen am Beispiel Rio de Janeiros},
  doi       = {10.25643/bauhaus-universitaet.47},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20040225-497},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  year      = {2002},
  abstract  = {Bei der Untersuchung der Tageslichtnutzung in den Tropen werden zun{\"a}chst die geschichtliche Entwicklung der Architektur in Rio de Janeiro und ihre klimatische Anpassung, die Tageslichtsituation vor Ort und die Bedingungen f{\"u}r den visuellen Komfort an Bildschirmarbeitspl{\"a}tzen in B{\"u}rogeb{\"a}uden analysiert. In einem zweiten Schritt werden Auslegungskriterien f{\"u}r Tageslichtkontrollsysteme festgelegt und ein Auslegungskonzept erarbeitet. Auf dieser Grundlage wird {\"u}ber Simulationen mit Siview/Radiance das Potential 12 verschiedener Tageslichtkontrollsysteme f{\"u}r verschiedene Himmelszust{\"a}nde ermittelt. {\"U}ber eine neu entwickelte Methodik wird die Tageslichtautonomie f{\"u}r verschiedene Fassadenorientierungen unter Einsatz der entwickelten Tageslichtkontrollsysteme f{\"u}r den Standort Rio de Janeiro ermittelt. Der Einfluss der M{\"o}blierung wird beispielhaft untersucht. Abschließend wird eine energetische Bilanz, die sowohl die Kunstlichteinsparung als auch die K{\"u}hllast durch Kunst- und Tageslicht ber{\"u}cksichtigt, an zwei Systemen beispielhaft erstellt.},
  subject      = {Rio de Janeiro},
  language  = {de}
}
@misc{Grossmann,
  author    = {Großmann, Felix},
  title     = {Capturing Sheep With Minecraft},
  doi       = {10.25643/bauhaus-universitaet.1753},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20121107-17530},
  pages     = {24},
  abstract  = {Capturing Sheep With Minecraft befasst sich mit ausgew{\"a}hlten Problemen der Bauphysik und deren Umsetzung mithilfe des Computerspiels Minecraft. Es werden ausgew{\"a}hlte Probleme der Bauphysik in Minecraft abgebildet um diese Sch{\"u}lern und Studenten n{\"a}her zu bringen. Es wurde ein Szenario in Minecraft entworfen welches durch entgegenwirken der abgebildeten Probleme, durch den Spieler gel{\"o}st werden soll.},
  subject      = {Minecraft},
  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}
}
@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}
}
@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{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}
}
@article{AlsaadHartmannVoelker,
  author    = {Alsaad, Hayder and Hartmann, Maria and Voelker, Conrad},
  title     = {The effect of a living wall system designated for greywater treatment on the hygrothermal performance of the facade},
  series = {Energy and Buildings},
  volume    = {2022},
  journal   = {Energy and Buildings},
  number    = {volume 255, article 111711},
  doi       = {10.1016/j.enbuild.2021.111711},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20240116-65299},
  pages     = {17},
  abstract  = {Besides their multiple known benefits regarding urban microclimate, living walls can be used as decentralized stand-alone systems to treat greywater locally at the buildings. While this offers numerous environmental advantages, it can have a considerable impact on the hygrothermal performance of the facade as such systems involve bringing large quantities of water onto the facade. As it is difficult to represent complex entities such as plants in the typical simulation tools used for heat and moisture transport, this study suggests a new approach to tackle this challenge by coupling two tools: ENVI-Met and Delphin. ENVI-Met was used to simulate the impact of the plants to determine the local environmental parameters at the living wall. Delphin, on the other hand, was used to conduct the hygrothermal simulations using the local parameters calculated by ENVI-Met. Four wall constructions were investigated in this study: an uninsulated brick wall, a precast concrete plate, a sandy limestone wall, and a double-shell wall. The results showed that the living wall improved the U-value, the exterior surface temperature, and the heat flux through the wall. Moreover, the living wall did not increase the risk of moisture in the wall during winter and eliminated the risk of condensation.},
  subject      = {Feuchteleitung},
  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}
}
@inproceedings{Dokhanchi,
  author    = {Dokhanchi, Najmeh Sadat},
  title     = {Reconstruction of the indoor air temperature distribution using acoustic travel-time tomography},
  editor    = {Arnold, J{\"o}rg},
  doi       = {10.25643/bauhaus-universitaet.4659},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220622-46593},
  abstract  = {Acoustic travel-time tomography (ATOM) is being increasingly considered recently as a remote sensing methodology to determine the indoor air temperatures distribution. It employs the relationship between the sound velocities along sound-paths and their related travel-times through measured room-impulse-response (RIR). Thus, the precise travel-time estimation is of critical importance which can be performed by applying an analysis time-window method. In this study, multiple analysis time-windows with different lengths are proposed to overcome the challenge of accurate detection of the travel-times at RIR. Hence, the ATOM-temperatures distribution has been measured at the climate chamber lab of the Bauhaus-University Weimar. As a benchmark, the temperatures of NTC thermistors are compared to the reconstructed temperatures derived from the ATOM technique illustrating this technique can be a reliable substitute for traditional thermal sensors. The numerical results indicate that the selection of an appropriate analysis time-window significantly enhances the accuracy of the reconstructed temperatures distribution.},
  subject      = {Bauphysik},
  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{VogelArnoldVoelkeretal.,
  author    = {Vogel, Albert and Arnold, J{\"o}rg and Voelker, Conrad and Kornadt, Oliver},
  title     = {Data for sound pressure level prediction in lightweight constructions caused by structure-borne sound sources and their uncertainties},
  series = {Data in Brief},
  volume    = {2023},
  journal   = {Data in Brief},
  number    = {Volume 48, June 2023, article 109292},
  publisher = {Elsevier},
  address   = {Amsterdam},
  doi       = {10.1016/j.dib.2023.109292},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20230719-64114},
  pages     = {1 -- 16},
  abstract  = {When predicting sound pressure levels induced by structure-borne sound sources and describing the sound propagation path through the building structure as exactly as possible, it is necessary to characterize the vibration behavior of the structure-borne sound sources. In this investigation, the characterization of structure-borne sound sources was performed using the two-stage method (TSM) described in EN 15657. Four different structure-borne sound sources were characterized and subsequently installed in a lightweight test stand. The resulting sound pressure levels in an adjacent receiving room were measured. In the second step, sound pressure levels were predicted according to EN 12354-5 based on the parameters of the structure-borne sound sources. Subsequently, the predicted and the measured sound pressure levels were compared to obtain reliable statements on the achievable accuracy when using source quantities determined by TSM with this prediction method.},
  subject      = {Bauakustik},
  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}
}
@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}
}