Nuclear power plants provide about 11 percent of the world's electricity production. For fission process is uranium fuels used with varying percentage of enrichment 235U for most of nuclear reactors. Uranium reserves are reducing and their mining cost increases. Therefore, the thorium fuel is discussed as revolution fuel for current and future nuclear power plants. This diploma thesis deals with possibility of thorium fuel utilization at various types of nuclear reactors with a focus on light water reactors. The practical part of the thesis is focused on simulation and calculations of various uranium dioxide and thorium dioxide layers at the fuel rods. Model of WWER 440 reactor was developed for the calculations with the addition of thorium fuel. The model simulates burning out of fuel for 5 years, with monitoring of fuel behavior and tracking changes of each material. The thesis tries to define the suitable ratio and parameters of layers combination of uranium and thorium fuel. For these ratios and parameters the thesis tries to give sufficient amount of computational analyzes.

Energy efficiency of the building sector is a key strategy to achieve national climate goals in Sweden and other European countries. In this thesis, several renovation scenarios for a case study office building in Sweden are analysed and compared based on their energy performance, environmental impacts, and economic costs from a life cycle perspective. As a baseline, the case study building was simulated in IDA ICE and compared with the simulated renovation scenarios. For the Life Cycle Analysis (LCA) and the Life Cycle Costs (LCC), the commercially available software OneClickLCA was used. The renovation scenarios were carried out over three rounds: (i) material type scenarios where five insulation materials (glass wool, rock wool, hemp fiber, Expanded Polystyrene (EPS), and Extruded Polystyrene (XPS)) and two frame materials (wood and steel) are compared; (ii) insulation thickness optimization from economic and environmental performance perspectives (iii) comparison of combination with other typical renovation measures such as changing of windows, improving specific fan power, heat exchanger efficiencies, and lightings. The results show that glass wool gives the most economical and environmental performance, followed by rock wool and EPS. When considering other environmental indicators, hemp fiber presents the best environmental option. However, it is not competitive with traditional insulation materials from an economic perspective. The insulation thickness scenarios show different optimal economic and environmental performance points, giving total energy savings of 5 % and 9,5 %, respectively. When considering other typical energy efficiency measures, the highest impact on the energy performance was found when improving the specific fan power (SFP) and switching to LED lights with total electricity reductions (including user-based electricity consumption) of 4 % and 14 %, respectively. Conclusively, the case study showed how the electricity and heating demand of the studied office building could be reduced, and the environmental and economic consequences of the different energy-efficiency measures.

[IT] Importanti cambiamenti sociodemografici, come la crescita della popolazione mondiale e l’urbanizzazione, stanno incrementando il fabbisogno di alimenti a livello mondiale. In contemporanea si sta assistendo ad una profonda trasformazione della dieta umana che tende sempre più a prediligere prodotti di origine animale, frutta e verdura al posto dei cereali. In quest’ottica, serre e stalle per l’allevamento intensivo possono ricoprire un ruolo di spicco, in quanto in grado di produrre tali alimenti con dei rendimenti decisamente maggiori rispetto a quelli che caratterizzano la produzione di vegetali in campo aperto e l’allevamento estensivo. Tra i vari fattori che contribuiscono ad incrementare la produttività di questi edifici agricoli vi è il controllo delle condizioni climatiche interne. Tale controllo del clima interno avviene, in molti casi, attraverso sistemi meccanici il cui utilizzo causa un considerevole consumo energetico che costituisce una minaccia per la transizione verso un’agricoltura più sostenibile. L’obiettivo generale di questa tesi è, quindi, di contribuire alla transizione verso un’agricoltura più sostenibile attraverso il miglioramento della prestazione energetica per il controllo climatico di serre e stalle per l’allevamento intensivo. Per raggiungere tale obiettivo, è stato adottato un triplice approccio basato su un’analisi di letteratura, campagne sperimentali di monitoraggio ed attività di modellazione energetica. L’analisi di letteratura è stata svolta con il fine di districare la complessa rete di relazioni esistente tra controllo climatico e altri domini di interesse della produzione agricola. Il nesso tra prestazione energetica e controllo climatico è stato approfondito analizzando dei set di dati reali acquisiti in una serra e due porcilaie attraverso campagne di monitoraggio. Questo nesso è stato ulteriormente approfondito adottando un approccio numerico che ha portato allo sviluppo e validazione di tre modelli di simulazione energetica per serre, per stalle da polli da carne e per stalle da suini da ingrasso. Ciascun modello di simulazione integra le principali caratteristiche tipiche di tali edifici per stimare con accuratezza i profili temporali delle condizioni ambientali interne e del consumo di energia termica ed elettrica. Le potenzialità di questi modelli nel migliorare la prestazione energetica e le condizioni climatiche di serre e stalle sono state esplorate analizzando specifiche problematiche relazionate al consumo energetico. Il modello energetico per le stalle per polli da carne, infatti, è stato adottato per valutare le potenzialità di un nuovo approccio per la progettazione energeticamente efficiente dell’involucro basato sull’energia primaria. Lo stesso modello è stato usato per valutare la variazione del consumo energetico causata dall’adozione di una strategia di ventilazione mirata al miglioramento del benessere dei polli allevati attraverso la riduzione della concentrazione interna di gas nocivi. Questa tesi contribuisce alla transizione verso una agricoltura più sostenibile fornendo nuove conoscenze e strumenti necessari al miglioramento della prestazione energetica per controllo climatico di serre e stalle per l’allevamento intensivo. Le analisi svolte, infatti, quantificano potenziali riduzioni del consumo energetico ottenibili attraverso l’implementazione di misure di efficientamento energetico, sia a livello di involucro (isolamento termico) che a livello di sistema di controllo climatico (ventilatori a portata variabile). Ulteriori misure per l’efficientamento energetico potrebbero essere valutate attraverso tali modelli che rappresentano importanti risultati di questa ricerca. Essi, infatti, potrebbero avere ricadute positive a livello locale in quanto vari portatori d’interesse (agricoltori, ingegneri e fabbricanti) potrebbero adottarli come strumenti di supporto alle decisioni per valutare nuove tecnologie, strategie e soluzioni mirate alla diminuzione del consumo energetico di serre e stalle. Questi nuovi modelli rappresentano anche un solido punto di partenza per future ricerche in questo campo. Futuri sviluppi potrebbero portare alla creazione di ulteriori moduli di calcolo per valutare altri aspetti, come la variazione della produttività, l’emissione di contaminanti e il benessere animale. Le nuove conoscenze generate in questa tesi potrebbero avere ricadute positive anche a livello globale, in quanto potrebbero rappresentare i fondamenti tecnici per nuovi quadri normativi e schemi di incentivi mirati al miglioramento della performance energetica di edifici agricoli controllati climaticamente attraverso una strategia di tipo top-down. / [ES] Importantes cambios sociodemográficos están conduciendo hacia un considerable crecimiento de la demanda de alimentos a nivel mundial. Al mismo tiempo se está observando una profunda transformación de la dieta humana, que tiende a incluir más productos de origen animal, fruta y verdura. Invernaderos y granjas de ganadería intensiva pueden desempeñar un papel principal, debido a que proporcionan los productos agrícolas necesarios con rendimientos notablemente mayores que los de la producción en campo abierto y de la ganadería extensiva. Entre los factores que contribuyen a incrementar la productividad de estos edificios agrícolas se sitúa el control de las condiciones climáticas internas. Dicho control se realiza a través de sistemas mecánicos cuyo uso causa un considerable consumo energético que representa una amenaza para la transición hacia una agricultura sostenible. El objetivo de esta tesis es contribuir a la transición hacia una agricultura más sostenible a través de la mejora de la prestación energética por control climático de invernaderos y granjas de ganadería intensiva. Para alcanzar dicho objetivo, se ha adoptado un enfoque triple basado en un análisis de literatura, campañas experimentales de monitorización y actividades de modelización energética. El análisis de literatura se ha llevado a cabo con el fin de desentrañar la red de relaciones existentes entre el control climático y otros dominios de interés de la producción agrícola. El nexo entre prestación energética y control climático se ha acometido analizando conjuntos de datos reales, adquiridos en un invernadero y dos granjas de cerdos. El análisis de dicho nexo se ha profundizado adoptando un enfoque numérico que ha llevado al desarrollo y validación de tres modelos de simulación energética para invernaderos y para granjas de pollos y cerdos. Las potencialidades de estos modelos para la mejora de las prestaciones energéticas y las condiciones climáticas se han explorado analizando problemáticas específicas. El modelo energético para granjas de pollos se ha adoptado para el diseño energéticamente eficiente de la envolvente de este tipo de edificio. El mismo modelo se ha usado para evaluar las variaciones de consumo energético causadas por la adopción de una estrategia de ventilación orientada a la mejora del bienestar de los pollos. Esta tesis contribuye a la transición hacia una agricultura más sostenible proporcionando nuevos conocimientos e instrumentos para la mejora de la prestación energética para el control climático de invernaderos y granjas. Los análisis realizados cuantifican potenciales disminuciones del consumo energético alcanzables a través de la implementación de medidas para la eficiencia energética a nivel de envolvente (aislamiento térmico) y a nivel de sistema de control climático (ventiladores con caudal variable). Ulteriores medidas para la eficiencia energética podrían evaluarse a través de dichos modelos que representan importantes resultados de esta investigación. Estos modelos podrían tener repercusiones positivas a nivel local, ya que muchas partes interesadas (agricultores, ingenieros y fabricantes) podrían adoptarlos como instrumentos de apoyo a la toma de decisiones para evaluar nuevas tecnologías y estrategias orientadas a la disminución del consumo energético. Estos nuevos modelos representan también un sólido punto de partida para futuras investigaciones en este campo. Futuros desarrollos podrían implementar nuevos módulos de cálculos para evaluar otros aspectos, como la variación de la productividad, la emisión de contaminantes y el bienestar animal. Los nuevos conocimientos generados en esta tesis podrían tener repercusiones positivas incluso a nivel global, puesto que podrían representar los fundamentos técnicos para nuevos marcos normativos y sistemas de incentivos orientados a la mejora de la prestación energética de edificios agrícolas controlados climáticamente a través de una estrategia de tipo top-down. / [CA] Importants canvis sociodemogràfics estan conduint cap a un considerable creixement de la demanda d'aliments a nivell mundial. Al mateix temps s'està observant una profunda transformació de la dieta humana, que tendeix a incloure més productes d'origen animal, fruita i verdura. Hivernacles i granges de ramaderia intensiva poden exercir un paper principal, pel fet que proporcionen els productes agrícoles necessaris amb rendiments notablement majors que els de la producció en camp obert i de la ramaderia extensiva. Entre els factors que contribueixen a incrementar la productivitat d'aquests edificis agrícoles se situa el control de les condicions climàtiques internes. Aquest control del clima intern es realitza a través de sistemes mecànics, l'ús dels quals causa un considerable consum energètic que representa una amenaça per a la transició cap a una agricultura sostenible. L'objectiu general d'aquesta tesi és contribuir a la transició cap a una agricultura més sostenible a través de la millora de la prestació energètica per al control climàtic d'hivernacles i granges de ramaderia intensiva. Per a aconseguir aquest objectiu, s'ha adoptat un enfocament triple basat en una anàlisi de literatura, campanyes experimentals de monitoratge i activitats de modelització energètica. L'anàlisi de literatura s'ha dut a terme amb la finalitat de desentranyar la complexa xarxa de relacions existents entre el control climàtic i altres dominis d'interés de la producció agrícola. El nexe entre prestació energètica i control climàtic s'ha analitzat amb conjunts de dades reals, adquirides en un hivernacle i dues granges de porcs. L'anàlisi d'aquest nexe s'ha aprofundit encara més adoptant un enfocament numèric que ha portat al desenvolupament i validació de tres models de simulació energètica per a hivernacles i per a granges de pollastres i porcs d'engreixament. Les potencialitats d'aquests models per a la millora de les prestacions energètiques i les condicions climàtiques s'han explorat analitzant problemàtiques específiques. El model energètic per a granges de pollastres s'ha adoptat per al disseny energèticament eficient de l'envolupant d'aquesta mena d'edifici. El mateix model s'ha usat per a avaluar les variacions de consum energètic causades per l'adopció d'una estratègia de ventilació orientada a la millora del benestar dels pollastres. Aquesta tesi contribueix a la transició cap a una agricultura més sostenible proporcionant nous coneixements i instruments per a la millora de la prestació energètica per al control climàtic d'hivernacles i granges. Les anàlisis realitzades quantifiquen potencials disminucions del consum energètic assolibles a través de la implementació de mesures per a l'eficiència energètica tant a nivell d'envolupant (aïllament tèrmic) com a nivell de sistema de control climàtic (ventiladors amb cabal variable). Ulteriors mesures per a l'eficiència energètica podrien avaluar-se a través d'aquests models que representen importants resultats d'aquesta investigació. Aquests models podrien tindre repercussions positives a nivell local, ja que moltes parts interessades (agricultors, enginyers i fabricants) podrien adoptar-los com a instruments de suport a la presa de decisions per a avaluar noves tecnologies i estratègies orientades a la disminució del consum energètic d'hivernacles i granges. Aquests nous models representen també un sòlid punt de partida per a futures investigacions en aquest camp. Futurs desenvolupaments podrien implementar nous mòduls de càlculs per a avaluar altres aspectes, com la variació de la productivitat, l'emissió de contaminants i el benestar animal. Els nous coneixements generats en aquesta tesi podrien tindre repercussions positives fins i tot a nivell global, ja que podrien representar els fonaments tècnics per a nous marcs normatius i sistemes d'incentius orientats a la millora de la prestació energètica d'edificis agrícoles controlats climàticament a través d'una estratègia de tipus top-down. / [EN] Socio-demographic trends, such as population growth and urbanization, are leading to a significant increase of the world food demand. At the same time, there is a shift of the human diet toward livestock products, vegetables, and fruit rather than cereals. Greenhouses and livestock houses can play a primary role since they can supply the necessary agricultural products with higher yields than on-field crop production and extensive animal farming. One way in which productivity is enhanced in these agricultural buildings is by a fine-tuned control of the indoor climate conditions. For this purpose, mechanical climate control systems are often adopted, but they entail a considerable energy consumption whose estimated increase may jeopardize the transition toward a sustainable agriculture. The overall objective of this thesis, hence, is to contribute to the transition toward a sustainable agriculture by improving the energy performance for climate control of greenhouses and livestock houses. To achieve this objective, a three-pronged approach was taken involving a literature review, experimental monitoring campaigns, and energy modelling activities. The literature review was performed to unpick the tangle of mutual relations between climate control and other domains of agricultural production. The nexus between energy performance and climate control was investigated analyzing real datasets acquired through monitoring campaigns performed in a greenhouse and two pig houses. This nexus was further studied adopting a numerical approach which led to the development and validation of three energy simulation models for greenhouses, broiler houses and pig houses. Each simulation model integrates the main features typical of greenhouses and livestock houses to estimate the time profiles of lumped indoor climate conditions and thermal and electrical energy consumption. The opportunities in improving the energy performance and the indoor climate conditions provided by the developed energy models were explored by analyzing specific energy-related problems. The broiler house energy model was adopted to evaluate the potentialities of a new primary energy approach for the energy-efficient envelope design of broiler houses. The same model was applied to evaluate the variation of energy consumption achieved by an improved ventilation strategy aimed at enhancing broiler welfare by reducing indoor noxious gas concentrations. This thesis contributes to the transition toward a more sustainable agriculture providing new knowledge and tools necessary for improving the energy performance for climate control of greenhouses and livestock houses. The performed analyses, in fact, quantify potential decrease of energy consumption achievable through the implementation of energy-efficient measures at both envelope -thermal insulation- and climate control system -variable angular speed fans- level. Further energy-efficient measures could be evaluated adopting the developed energy simulation models that are valuable outputs of this investigation. These models could have a positive impact at local level since stakeholders -farmers, engineers, and manufacturers- could adopt them as decision support tools for the evaluation of new technologies, strategies and solutions aimed at decreasing the overall energy consumption of greenhouses and livestock houses. These novel models represent also a robust starting point for future research in this field. Future advances may lead to the development of further calculation modules to evaluate other aspects of greenhouses and livestock houses, such as productivity variations, contaminant emissions and animal welfare. The new knowledge generated in this thesis could have positive impacts also at global level since it may represent the technical basis for new normative frameworks and incentive schemes aimed at improving the energy performance of climate-controlled agricultural buildings through a top-down approach. / Costantino, A. (2021). Improving Climate Control and Energy Performance in Greenhouses and Livestock Houses: Modelling Advances and Experimental Results [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/178457 / TESIS

Es ist ein politisch erklärtes Ziel, den Ausstoß von klimaschädlichen Treibhausgasen weltweit zu verringern. Eine wesentliche Stellschraube im Gebiet des Bauwesens stellt hierbei die Einsparung von Energien zur Raumkonditionierung dar. Diese wird unter anderem über das Lüftungskonzept beeinflusst. Die Belüftung von Gebäuden ist zwingend notwendig, um die Emissionen der Baustoffe und die der Menschen, beispielsweise ihren CO2-Ausstoß über die Atmung, abzuführen und der Schimmelbildung vorzubeugen. Erfolgt die Belüftung über öffenbare Fenster – natürliche Lüftung – wird so allerdings energetisch aufwändig temperierte Raumluft mit untemperierter Außenluft ausgetauscht. Daraus können Wärmeverluste und thermisches Unbehagen resultieren. Energieeffiziente Technologien sind ventilatorgestützte Lüftungssysteme mit Wärmerückgewinnung. Doch nicht für alle Gebäudekonzepte und Nutzer stellen diese Lüftungskonzepte einen hohen Nutzerkomfort dar. Korrelationen zwischen Gebäuden mit ventilatorgestützten Lüftungsystemen und dem Sick-Building-Syndrom sind in der Literatur beschrieben, während hier für natürliche Lüftungskonzepte keine Korrelation besteht. Stattdessen wird in Nutzerbefragungen der natürlichen Lüftung eine hohe Akzeptanz zugeschrieben. Mit elektrisch angetriebenen Fenstern kann die natürliche Lüftung nutzerunabhängig gesteuert und so Wärmeverluste und thermisches Unbehagen kontrolliert werden. Bisher sind die Auslegungen solcher kontrollierten natürlichen Lüftungskonzepte noch sehr planungsintensiv. Das Ziel der Arbeit ist es, für Büro- und Verwaltungsgebäude Öffnungs- und Schließsignale einer kontrollierten natürlichen Lüftung zu geben. Diese zeichnen sich darüber aus, dass sie ein gesundes Raumklima, eine hohe Nutzerbehaglichkeit und Energieeffizienz über den Jahresverlauf schaffen und auf ihre Robustheit gegenüber Änderungen von Gebäuderandbedingungen überprüft sind. Für das Ziel wird ein über CO2- und Temperatursensoren gesteuertes Fenstersystem mittels dynamisch thermischer Gebäudesimulationen in vier Varianten von Schließsignalen auf thermische Behaglichkeit und Energiebedarf untersucht. Die Grundlage dazu stellt die bezüglich Entwurf, Konstruktion und Nutzung allgemeingültige Entwicklung eines Büroraums dar. Der Büroraum wird im Simulationsmodell abgebildet und in Realität errichtet. Die Kombination von Simulationsmodell und realem, als experimentellem Teststand ausgeführtem Büroraum ermöglicht verifizierte Ergebnisse. So werden vier Berechnungsmodelle für Luftvolumenströme von Fenstern über den Teststand verifiziert. Dazu dienen Luftwechselmessungen nach der Konstantinjektionsmethode an 173 Fensteröffnungen für fünf Außentemperatur- und elf Windgeschwindigkeitsbereiche. Das Berechnungsmodell nach DIN EN 16798-7 zeigt sich als realitätsnah. Da dieses Berechnungsmodell nicht im Gebäudesimulationsprogramm implementiert ist, wird eine Methode zur Implementierung entwickelt. Über das entwickelte Simulationsmodell zeigt sich, dass eine kombinierte CO2- und temperaturgesteuerte kontrollierte natürliche Lüftung nur zweimal im Jahr ihre Grenzwerte zur Fensteröffnung und -schließung variieren muss, um ganzjährig eine hohe Energieeffizienz und Nutzerbehaglichkeit zu schaffen. Die Schließsignale des sensorgesteuerten Fenstersystems werden in eine Zeitsteuerung überführt. Es zeigt sich, dass für die kühlen Monate jede Öffnung mit identischer Dauer angesetzt werden darf. In wärmeren Monaten muss die Öffnungsdauer in Abhängigkeit der Außentemperatur angepasst werden, so dass eine Zeitsteuerung mit einer Außentemperaturmessung gekoppelt werden muss. Die Ergebnisse zeigen, dass über eine Variation der Schließsignale einer kontrollierten natürlichen Lüftung die Energieeffizienz und die thermische Behaglichkeit wesentlich gesteigert werden und dass selbst bei geringen Windgeschwindigkeiten und Temperaturdifferenzen die Raumluftqualität stets gewährleistet ist. Für nahezu alle Standorte in Deutschland kann die kontrollierte natürliche Lüftung so den Kühlbedarf der untersuchten Büroräume eliminieren, ohne in einer sommerlichen Überhitzung der Räume zu resultieren. Die entwickelten und bezüglich Raumluftqualität und thermischer Behaglichkeit charakterisierten Sensor- und Zeitsteuerungen tragen dazu bei, die kontrollierte natürliche Lüftung als wartungsarme, technikreduzierte Alternative zu der ventilatorgestützten Lüftung zu etablieren.:1 Einleitung 2 Natürliche Lüftung 3 Kontrollmöglichkeiten der natürlichen Lüftung 4 Entwicklung der Untersuchungsmodelle 5 Voruntersuchungen 6 Sensorsteuerung für den Basisraum 7 Zeitsteuerung für den Basisraum 8 Übertragung auf unterschiedliche Gebäuderandbedingungen 9 Diskussion und Empfehlungen 10 Zusammenfassung und Ausblick 11 Literatur 12 Abbildungsnachweis 13 Bezeichnungen 14 Anhang / It is a politically declared goal to reduce the emission of climate-damaging greenhouse gases worldwide. To support this goal by the building industry a key driver is the saving of energy for room conditioning. Among other factors, this is influenced by the ventilation concept. Also the ventilation of buildings is absolutely necessary in order to remove the emissions of the building materials and those of the people, for example their CO2 emissions through breathing as well as to prevent mould. However, if ventilation is carried out via openable windows - natural ventilation - then energetically expensive tempered room air is exchanged with cold outside air. This could result in heat loss and thermal discomfort. Mechanical ventilation systems with heat recovery are energy-efficient technologies. However, these ventilation concepts do not represent a high level of user comfort for all building concepts and users. Correlations between buildings with mechanical ventilation systems and sick building syndrome are described in the literature, while there is no such correlation for natural ventilation concepts. Instead, a high level of acceptance is attributed to it in user surveys. With electrically driven and controlled windows, natural ventilation can be controlled independently from the user, thus minimizing heat loss and thermal discomfort. So far, the design of such controlled natural ventilation concepts is still very planning-intensive. The aim of this work is to provide opening and closing signals for controlled natural ventilation in office buildings. These are characterized for their capability to create a high indoor air quality, high user comfort and high energy efficiency over the course of the year and are tested for their robustness against changes in building characteristics. To achieve this goal, a window system controlled by CO2 and temperature sensors is examined for its impact on thermal comfort and energy demand by means of building simulation tools with four variants of closing signals. As a basis for this examination an office room is utilized that conforms to the current standards in terms of design, construction and use. The office space is transferred to a simulation model and constructed in reality. The combination of the simulation model and the real office space, which is designed as an experimental test rig, enables verified results. Thus, four calculation models for air flow volumes of windows are verified via the test rig. Air exchange measurements according to the constant injection method on 173 window openings for five outdoor temperature and eleven wind speed ranges are used for this purpose. The calculation model according to DIN EN 16798-7 proves to be close to reality. Since this calculation model is not implemented in the building simulation program, a method for its implementation is developed. Using the developed simulation model, it is shown that a combined CO2- and temperature-controlled natural ventilation creates a high energy efficiency and user comfort throughout the year by varying its limit values for window opening and closing only twice a year. The closing signals of the sensor controlled window system are transferred to a time control system. It turns out that for the cold months, each opening could be set to the same opening time. In warmer months, the opening time must be adjusted depending on the outside temperature. Thus, a time control should be coupled with an outside air temperature measurement. The results show that by varying the closing signals of a controlled natural ventilation system, the energy efficiency and thermal comfort is significantly increased and that a high indoor air quality is always guaranteed even at low wind speeds and low temperature differences. For almost all locations in Germany, controlled natural ventilation can thus eliminate the cooling requirements in the office spaces studied without overheating in the summer. The developed sensor and time control systems are characterized by high indoor air quality and good thermal comfort. Thus, these systems are a contribution to promote controlled natural ventilation as a low-maintenance and technically reduced alternative to mechanical ventilation.:1 Einleitung 2 Natürliche Lüftung 3 Kontrollmöglichkeiten der natürlichen Lüftung 4 Entwicklung der Untersuchungsmodelle 5 Voruntersuchungen 6 Sensorsteuerung für den Basisraum 7 Zeitsteuerung für den Basisraum 8 Übertragung auf unterschiedliche Gebäuderandbedingungen 9 Diskussion und Empfehlungen 10 Zusammenfassung und Ausblick 11 Literatur 12 Abbildungsnachweis 13 Bezeichnungen 14 Anhang