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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Energianvändning i badhus : Simulering och jämförelse av gamla och nya system / Energy use in public baths : simulation and comparsion of old and new systems

Fredriksson, Lisa January 2012 (has links)
Every year new premises are built in Sweden, and even if they are made as energy efficient as possible, this will not reduce the energy demands, but the rate of the increase of the energy use will be reduced. One type of facility in Sweden that is a major energy user is public baths, and this makes public baths an interesting facility to study more closely. There are around 500 public baths in Sweden and about 75 % of those can be seen as older baths with large need of renovation, and they all require a high level of energy efficiency measures. To show how the energy demand increase or decrease depending on the changes chosen to be made, the simulation application IDA Indoor Climate and Energy was used. Simulations were made and compared for several cases, with two extreme cases as starting points. The cases were older and newer ventilation systems, with and without return air flow, older and newer building envelopes and how the indoor climate and the energy demand is affected by the swimming pool covered or not covered during the night. The biggest difference in heat demand was found to be in the two extreme cases, and the use of recirculated air has the highest impact.
52

Tolérance et efficacité de la ventilation non invasive à domicile chez 44 patients âgés de 75 ans et plus

Papin, Olivier Chollet, Sylvaine. January 2005 (has links) (PDF)
Thèse d'exercice : Médecine. Médecine générale : Université de Nantes : 2005. / Bibliogr. f. 101-106 [ 63 réf.].
53

Prédiction des performances thermo-aérauliques des bâtiments par association de modèles de différents niveaux de finesse au sein d'un environnement orienté objet

Mora, Laurent Inard, Christian January 2003 (has links)
Thèse doctorat : Génie civil : La Rochelle : 2003. / Bibliogr. p. 173-182.
54

Développement et évaluation de stratégies de contrôle de ventilation appliquées aux locaux de grandes dimensions

Cordier, Nicolas Michel, Pierre January 2007 (has links)
Thèse doctorat : Génie Civil : Villeurbanne, INSA : 2007. / Titre provenant de l'écran-titre. Bibliogr. p. 315-321.
55

Analysis of complex ventilation networks in multiple fan coal mines

El-Nagdy, Khaled Ali. January 1900 (has links)
Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains xvii, 181 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 157-161).
56

Functional model and second law analysis method for energy efficient process design applications in HVAC systems design /

Harutunian, Vigain, Jones, J. W. January 2003 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2003. / Supervisor: Jerold W. Jones. Vita. Includes bibliographical references. Available also from UMI Company.
57

Air flow disturbance by moving objects at local exhaust ventilation

Aguirre Sánchez, Mikel January 2015 (has links)
The present thesis aims to study the effect of human movements on local exhaust ventilation. In its simplest terms, local exhaust ventilation is a system which has the function of extracting contaminated air situated close to the contaminant source, protecting a working person from exposure to hazardous substances by containing or capturing them locally, at the emission point. As an important security measure referred to terms of health, it is crucial for the healthiness of workers to control and prevent them from the exposure to vapour, mist, dust or other airborne contaminants. Additionally, to a lesser degree of significance, it can be stressed an expected increase in worker performance due to an improvement of the working conditions. There is an existing necessity for well-defined and appropriate methods to test the performance of local exhaust devices in order to reach standard efficiency values. The lack of an international standardization led to the realization of this study, which, ultimately, has the purpose of obtaining relevant results that can be utilized for future normalized test procedures. The study entails full scale experimental measurements that include air velocity measurements in 3 dimensions, a local exhaust ventilation device with circular hood and a flat flanged plate and a controlled generation of air turbulence through physical movements of a human-sized cylinder, simulating a walking person. The present study extends previous similar studies at the University of Gävle, where the controlled air turbulence was generated by a moving plate. After meaningful results obtained in that study, one of the considerations was to better simulate a walking person, by replacing the plate for a movable cylinder. The present study points at a larger similarity occurring with a cylinder than with a plate, as regards the air flow pattern produced by a real walking person. As in the previous study, the Percentage of Negative Velocities, PNV, has been used as the main measure of turbulence induced risk of contaminant spread. The PNV represents the fraction of the time when the flow is directed opposite to the suction air stream in front of the local exhaust hood. The obtained results conclude that the use of the cylinder as a moving object has been an improvement to simulate the effect of the movement of a human being on a relaxed walking pace. The present study was carried out in parallel with the thesis work by Leyre Catalán Ros, which complements this study by analyzing the effect of an added heated dummy, simulating a person seated in front of the local exhaust device.
58

Relative effectiveness of ventilation in community indoor environmentsfor controlling infection

Gao, Xiaolei., 高晓磊. January 2011 (has links)
The existence, probability and control measures of airborne infections have been widely discussed for centuries. Although public belief regarding airborne infection kept on altering throughout the entire history of medicine and is still controversial, many airborne transmission experiments and airborne infection outbreak analyses have been carried out. Different airborne transmission models have been built and various airborne control measures have been evaluated. One of the major knowledge gaps obstructing applications of some airborne control measures in clinical practices and public applications is that there is a lack of evidence in proving the effectiveness of such measures. Ventilation as an important airborne infection control method can be achieved by opening windows, or increasing the outdoor air supply rate in mechanical ventilation systems or indirectly by using filters and ultraviolet equipments. However the applications of ventilation in infection control were largely restricted to isolation rooms rather than regarded as a public control measure. In this study we focus on evaluating the effectiveness of ventilation as a community measure. Results, therefore, can provide evidence for using ventilation as a public health measure for controlling respiratory diseases transmitted by the airborne route or multi-routes. Two mathematical modeling approaches (deterministic model and social network model) are adopted to estimate different airborne diseases outbreaks with a focus on ventilation and a corresponding analysis of their relative effectiveness compared with other public health measures. A comprehensive understanding of detailed control strategies (including both engineering and public health control) will be achieved through gradually complicated and realistic models. It’s commonly believed that many respiratory infections are transmitted through multiple routes including airborne, droplet-borne and contact routes. Hence the effectiveness of airborne control measures was doubted when the airborne route was not dominant. Therefore, we developed a model to simulate partially airborne transmitted diseases outbreaks and evaluated the relative effectiveness of ventilation when the role of airborne transmission altered. Knowing the complex transmission mechanisms of respiratory transmission and the role of the airborne route in the transmission process is essential in determining the effectiveness of airborne control measures. Hence in this study we also tested the virus exposures dose to infectious patients at different distances when patients were carrying out different respiratory activities. A complex model considering transmission mechanisms of respiratory infections was also built to evaluate the influence of the transmission route in large scale outbreak simulations. The results showed that increasing ventilation rate especially in homes, offices and classrooms is an effective control method for controlling airborne and partially airborne transmitted infections. Combining isolation and increasing ventilation rate can reach similar or even better control effect compared with other general public health interventions such as vaccination. This finding suggested the important role of ventilation in airborne infectious disease prevention and intervention. The ventilation rate required by existing ventilation standards such as ASHRAE 62 might be too low for the purpose of controlling possible airborne outbreaks. / published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy
59

Effect of internal thermal mass on building thermal performance

Yam, Chi-wai., 任志偉. January 2003 (has links)
published_or_final_version / abstract / toc / Mechanical Engineering / Master / Master of Philosophy
60

A framework for the implementation of design assistances for preliminary concept design of laboratories

Sheward Garcia, Hugo A. 21 September 2015 (has links)
A framework for the implementation of automated ventilation systems engineering was proposed. An extensive research in the area of design guidelines and best practices for the design and operations of laboratories was conducted. a software prototype was created to better support the integration of ventilation engineering to early design stages was created. New methodologies for enhancing the semantics and for deriving building morphology information from early design BIM models were created. The prototype software was tested using as reference currently available practices. Findings concerning the speed of operation, the extended capabilities of the proposed framework and the implication for future research are discussed.

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