Download or read book A Ventilation Strategy Based on Confluent Jets written by Setareh Janbakhsh and published by Linköping University Electronic Press. This book was released on 2015-04-27 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study presents air distribution systems that are based on confluent jets; this system can be of interest for the establishment of indoor environments, to fulfill the goals of indoor climate and energy-efficient usage. The main objective of this study is to provide deeper understanding of the flow field development of a supply device that is designed based on wall confluent jets and to investigate the ventilation performance by experimental and numerical methods. In this study, the supply device can be described as an array of round jets on a flat surface attached to a side wall. Multiple round jets that issue from supply device apertures are combined at a certain distance downstream from the device and behave as a united jet or so-called confluent jets. Multiple round jets that are generated from the supply device move downward and are attached to the wall at the primary region, due to the Coanda effect, and then they become wall confluent jets until the floor wall is reached. A wall jet in a secondary region is formed along the floor after the stagnation region. The characteristics of the flow field and the ventilation performance of conventional wall confluent jets and modified wall confluent jets supply devices are investigated experimentally in an office test room. The study of the modified wall confluent jets is intended to improve the efficiency of the conventional one while maintaining acceptable thermal comfort in an office environment. The results show that the modified wall confluent jets supply device can provide acceptable thermal comfort for the occupant with lower airflow rate compared to the conventional wall confluent jets supply device. Numerical predictions using three turbulence models (renormalization group (RNG k– ?), realizable (Re k– ?), and shear stress transport (SST k– ?) are evaluated by measurement results. The computational box and nozzle plate models are used to model the inlet boundary conditions of the nozzle device. In the isothermal study, the wall confluent jets in the primary region and the wall jet in the secondary region, when predicted by the three turbulence models, are in good agreement with the measurements. The non-isothermal validation studies show that the SST k– ? model is slightly better at predicting the wall confluent jets than the other two models. The SST k– ? model is used to investigate the effects of the nozzle diameter, number of nozzles, nozzle array configuration, and inlet discharge height on the ventilation performance of the proposed wall confluent jets supply device. The nozzle diameter and number of nozzles play important roles in determining the airflow pattern, temperature field, and draught distribution. Increased temperature stratification and less draught distribution are achieved by increasing the nozzle diameter and number of nozzles. The supply device with smaller nozzle diameters and fewer nozzles yields rather uniform temperature distribution due to the dominant effect of mixing. The flow behavior is nearly independent of the inlet discharge height for the studied range. The proposed wall confluent jets supply device is compared with a mixing supply device, impinging supply device and displacement supply device. The results show that the proposed wall confluent jets supply device has the combined behavior of both mixing and stratification principles. The proposed wall confluent jets supply device provides better overall ventilation performance than the mixing and displacement supply devices used in this study. This study covers also another application of confluent jets that is based on impinging technology. The supply device under consideration has an array of round jets on a curve. Multiple jets issue from the supply device aperture, in which the supply device is positioned vertically and the jets are directed against a target wall. The flow behavior and ventilation performance of the impinging confluent jets supply device is studied experimentally in an industrial premise. The results show that the impinging confluent jets supply device maintains acceptable thermal comfort in the occupied zone by creating well-distributed airflow during cold and hot seasons.

Download or read book On the performance of stratified ventilation written by Ulf Larsson and published by Linköping University Electronic Press. This book was released on 2018-08-20 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: People nowadays spend most of their time indoors, for example in their homes, cars, in trains, at work, etc. In Sweden, the energy demand in the built environment is a growing issue. The building sector accounts for 40% of total energy use and 15% of total CO2 emissions, and around one-third of the energy use in the world is related to providing a healthy and good comfort indoors. To achieve acceptable indoor climates new designs for the ventilation systems have been proposed in recent decades, among them stratified ventilation systems. Stratified ventilation is a concept that often allows good performance for both indoor air quality and thermal comfort. Stratified ventilation systems are effective in reducing cross contamination, since there is virtually no mixing in the space; the temperature and the pollutant concentration increase linearly from the heat source with the height of the occupied zone. There are many different ventilation supply devices using the stratified principle, such as displacement supply device (DSD), impinging jet supply device (IJSD) and wall confluent jet supply device (WCJSD). The main aim of this thesis is to analyze and compare different supply devices based on stratified ventilation, with different setups, related to thermal indoor climate, energy efficiency and ventilation efficiency. The ultimate goal is to contribute to an increased understanding of how ventilation systems with stratified supply devices perform. Two scientific methods have mainly been used in this thesis, i.e., experimental and numerical investigations. For numerical experiments the CFD (Computational Fluid Dynamics) code ANSYS and FIDAP have been used. Experimental studies have been performed with thermocouples, Hot-Wire Anemometry (HWA) and Hot-Sphere Anemometry, thermal comfort measurement equipment and tracer gas measurement equipment. This thesis mainly focuses on three research questions: Interaction between a supply device based on stratified ventilation and downdraft from windows; Flow behavior, energy performance and air change effectiveness for different supply devices based on stratified ventilation; and Thermal comfort for different supply devices based on stratified ventilation. Research question one showed that the arrangement of displacement supply device and window in cold climate has significant effect on the flow pattern below the window. Different supply airflow rates have an effect on both the velocity and the temperature of the downdraft. In this case the velocity decreased by approximately 9.5% and the temperature in the downdraft decreased 0.5°C when the flowrate from the supply device increased from 10 to 15 l/s. Research question two showed that airflow patterns between different air supply systems were essentially related to characteristics of air supply devices, such as the type, configuration and position, as well as air supply velocities and momentum. For WCJSD, IJSD and DSD, positions of heat sources (such as occupant, computers, lights and external heat sources) played an important role in formation of the room airflow pattern. One interesting observation is that the temperature in the occupied zone is lower and a more stratified temperature field implies a more efficient heat removal by a stratified air supply device. The results revealed that the lowest temperature in the occupied zone was achieved for DSD, but with IJSD and WCJSD slightly warmer, while the system with a mixing supply device (MSD) showed a much higher temperature. The results confirm that air change effectiveness (ACE) for the DSD, WCJSD and IJSD is close to each other. However, MSD shows lower ACE in all the present papers than IJSD, WCJSD and DSD. Research question three showed that ventilation systems with stratified supply devices in almost all of the studied cases showed an acceptable level for predicted percentage dissatisfied (PPD), predicted mean vote (PMV) and percentage dissatisfied due to draft (DR). If comparing ventilation systems, using IJSD, WCJSD or DSD with MSD always showed thermal comfort better or at the same level. Människor spenderar en stor del av sin tid inomhus, exempelvis i sina bostäder och bilar, på tåg och på arbetet. Sveriges energibehov i den byggda miljön har en växande trend. Byggnadssektorn står för 40 % av det totala energibehovet och för 15 % av CO2 utsläppet och för cirka en tredjedel av energianvändningen i världen för att tillhandahålla en hälsosam och bra inomhusmiljö. För att skapa en bra inomhusmiljö har nya sätt att ventilera inomhusmiljön utvecklats under de senaste årtiondena. De olika principer som används för att ventilera en byggnad kan indelas i: kolvströmning, omblandande strömning och deplacerande strömning. De genererar rumsförhållanden som ger olika fördelning av hastighet, temperatur och föroreningar i det ventilerade utrymmet. Stratifierad ventilation är ett koncept som ofta ger ett bra utfall av både inomhusluftkvalitet och termisk komfort. Stratifierade system är effektiva för att minska korskontaminering, eftersom det nästan inte finns någon omblandning i rummet, temperaturen och föroreningskoncentration ökar linjärt från värmekällan med höjden i vistelsezonen. Det finns många olika ventilationsdon som använder den stratifierade principen, såsom deplacerande ventilationsdon (DSD), impinging jet-ventilationsdon (IJSD) och väggbaserad confluent jet-ventilationsdon (WCJSD). Huvudsyftet med denna avhandling är att analysera och jämföra olika tilluftsdon baserat på stratifierad princip i olika rumskonfigurationer med avseende på termiskt inomhusklimat, energieffektivitet och ventilationseffektivitet. Det yttersta målet är att bidra till ökad förståelse för hur ventilationssystem med olika stratifierade tilluftsdon fungerar. Två vetenskapliga metoder har huvudsakligen använts i denna avhandling: experimentella och numeriska analyser. För numeriska analyser har CFD (Computational Fluid Dynamics) använts. De simuleringsprogram som utnyttjats för detta ändamål är ANSYS och FIDAP. Experimenten har utförts med hjälp av termoelement, varmtråds- och varmsfärsteknik, mätutrustning för termisk komfort och mätutrustning för spårgas. Denna avhandling fokuserar framför allt på tre forskningsfrågor: interaktion mellan ett tilluftsflöde från ett deplacerande don och kallraset från ett fönster; strömningsbilden, energiprestandan och luftbyteseffektiviteten för olika tilluftsdon baserat på stratifierad ventilation; och termisk komfort för olika tilluftsdon baserade på stratifierad ventilation. Forskningsfråga ett visade att kombinationen av tilluftsflöde genom ett deplacerande don och fönster i kallt klimat har tydlig effekt på strömningsbilden för kallraset under fönstret. Olika tilluftsflöden har en effekt på både hastigheten och temperaturen i kallraset. I detta fall minskade hastigheten med ca 9,5% och temperaturen i kallraset minskade med 0,5°C när flödeshastigheten från tilluftsdonet ökade från 10 till 15 l/s. Forskningsfråga två visade att luftflödesmönstren mellan olika luftförsörjningssystem väsentligen var relaterade till egenskaper hos tilluftsdonen, såsom typ, konfiguration och position samt lufttillförselhastigheter och impulskraft. För WCJSD, IJSD och DSD spelade värmekällans placering, d.v.s. människor, datorer, belysning och externa värmekällor, en viktig roll vid utformningen av rummets luftflödesmönster. En intressant observation är att temperaturen i vistelsezonen är lägre och rummet har ett mer stratifierat temperaturfält, vilket innebär en effektivare ventilering av den zonen. Resultaten visade att den lägsta temperaturen i vistelsezonen uppnåddes för DSD medan IJSD och WCJSD visade en något högre temperatur, systemet med ett omblandande don (MSD) visade en påtagligt högre temperatur. Resultaten bekräftar också att luftförändringseffektiviteten (ACE) för DSD, WCJSD och IJSD ligger nära varandra. MSD visar dock i alla ingående artiklar lägre ACE än IJSD, WCJSD och DSD. Forskningsfråga tre visade att ventilationssystem med stratifierade tilluftsdon i nästan samtliga studerade fallen haren acceptabel nivå för predicted mean vote (PPD), predicted mean vote (PMV) och percentage dissatisfied due to draft (DR). Om man jämförde ventilationssystem IJSD, WCJSD eller DSD med MSD visade det sig alltid att den termiska komforten var bättre eller på samma nivå som för MSD.

Download or read book Proceedings of EcoComfort 2024 written by Zinoviy Blikharskyy and published by Springer Nature. This book was released on with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Urban Transition written by Marita Wallhagen and published by BoD – Books on Demand. This book was released on 2023-12-20 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of CEE 2019 written by Zinoviy Blikharskyy and published by Springer. This book was released on 2019-08-08 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers the latest advances, innovations, and applications in the field of effective methods of calculation, resource-saving technologies and advanced materials in civil and environmental engineering, as presented by leading international researchers and engineers at the XVII International Scientific Conference Current Issues of Civil and Environmental Engineering “Lviv- Košice – Rzeszów”, held in Lviv, Ukraine on September 11-13, 2019. It covers highly diverse topics, including structural shaping and optimization; aspects of structural behavior and modeling; advanced analysis methods; experimental tests and numerical simulations; design codes, in particular Eurocodes and other national and regional limit state codes; and highway and bridges engineering. It also discusses modern architectural and structural solutions; innovative materials and products; durability and maintenance; fabrication and erection; sustainability in construction; renewable energy sources; heat, gas and water supply; ventilation and air-conditioning; ecological and energy-saving technologies, modern water-purification and treatment technologies; and the protection of water ecosystems. The contributions, which were selected by means of a rigorous international peer-review process, highlight numerous exciting ideas that will spur novel research directions and foster multidisciplinary collaborations.

Download or read book Challenges Opportunities and Solutions in Structural Engineering and Construction written by Nader Ghafoori and published by CRC Press. This book was released on 2009-10-29 with total page 1032 pages. Available in PDF, EPUB and Kindle. Book excerpt: Challenges, Opportunities and Solutions in Structural Engineering and Construction addresses the latest developments in innovative and integrative technologies and solutions in structural engineering and construction, including: Concrete, masonry, steel and composite structures; Dynamic impact and earthquake engineering; Bridges and

Download or read book Office Buildings written by Pranab Kumar Nag and published by Springer. This book was released on 2018-12-31 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together concepts from the building, environmental, behavioural and health sciences to provide an interdisciplinary understanding of office and workplace design. Today, with changes in the world of work and the relentless surge in technology, offices have emerged as the repositories of organizational symbolism, denoted by the spatial design of offices, physical settings and the built environment (architecture, urban locale). Drawing on Euclidian geometry that quantifies space as the distance between two or more points, a body of knowledge on office buildings, the concept of office and office space, and the interrelationships of spatial and behavioural attributes in office design are elucidated. Building and office work-related illnesses, namely sick building syndrome and ailments arising from the indoor environment, and the menace of musculoskeletal disorders are the alarming manifestations that critically affect employee satisfaction, morale and work outcomes. With a focus on office ergonomics, the book brings the discussion on the fundamentals of work design, with emphasis on computer workstation users. Strategic guidance of lighting systems and visual performance in workplaces are directed for better application of ergonomics and improvement in office indoor environment. It discusses the profiles of bioclimatic, indoor air quality, ventilation intervention, lighting and acoustic characteristics in office buildings. Emphasis has been given to the energy performance of buildings, and contemporary perspectives of building sustainability, such as green office building assessment schemes, and national and international building-related standards and codes. Intended for students and professionals from ergonomics, architecture, interior design, as well as construction engineers, health care professionals, and office planners, the book brings a unified overview of the health, safety and environment issues associated with the design of office buildings.

Download or read book Attachment Ventilation Theory written by Angui Li and published by Springer Nature. This book was released on 2023-05-02 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book systematically summarizes the current research progress of attachment ventilation, covering vertical wall attachment, column attachment, and adaptive attachment ventilation. Attachment ventilation is a high-performance ventilation mode that was first proposed by the author, Prof. Angui Li 20 years ago. Now it has been widely used in office spaces, subway stations, high-speed railway stations, international airport terminals, and other large spaces. This book introduces attachment ventilation in detail to eliminate the cooling/heating load of the occupied zone and provide an expected environment for the air-conditioned zone. Attachment ventilation combines the advantages of traditional mixed ventilation and displacement ventilation. This book consists of six chapters, covering a series of airflow patterns, mechanisms, parameter correlations, and attachment ventilation design methods. It is helpful for HVAC engineers to design attachment ventilation effectively.

Download or read book Proceedings of the 1st International Conference on Water Energy Food and Sustainability ICoWEFS 2021 written by João Rafael da Costa Sanches Galvão and published by Springer Nature. This book was released on 2021-05-08 with total page 947 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the proceedings of the 1st International Conference on Water Energy Food and Sustainability – ICoWEFS 2021, a major forum to foster innovation and exchange knowledge in the water-energy-food nexus, embracing the Sustainable Development Goals (SDGs) of the United Nations, bringing together leading academics, researchers and industrial experts. It contains the work of authors from 33 countries.

Download or read book Ventilation of Buildings written by H.B. Awbi and published by Routledge. This book was released on 2004-06-02 with total page 537 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hazim Awbi's Ventilation of Buildings has become established as the definitive text on the subject. This new, thoroughly revised, edition builds on the basic principles of the original text drawing in the results of considerable new research in the field. A new chapter on natural ventilation is also added and recent developments in ventilation concepts and room air distribution are also considered. The text is intended for the practitioner in the building services industry, the architect, the postgraduate student undertaking courses or research in HVAC, building services engineering, or building environmental engineering, and the undergraduate studying building services as a major subject. Readers are assumed to be familiar with the basic principles of fluid flow and heat transfer and some of the material requires more advanced knowledge of partial differential equations which describe the turbulent flow and heat transfer processes of fluids. The book is both a presentation of the practical issues that are needed for modern ventilation system design and a survey of recent developments in the subject

Download or read book Oh s Intensive Care Manual E Book written by Andrew D Bersten and published by Elsevier Health Sciences. This book was released on 2008-12-05 with total page 1292 pages. Available in PDF, EPUB and Kindle. Book excerpt: The sixth edition of Oh’s Intensive Care Manual provides practical, concise information on all aspects of intensive care. Written in a clear and accessible style and now for the first time presented in colour throughout, this book enables the user to manage a patient in an ICU setting effectively without recourse to large text/reference works or specialized monographs. This thoroughly revised and updated edition reflects the best and most current practice from leading centres in Australia, the UK and Western Europe. Although primarily intended for the trainee and practitioner in intensive care, nurses and other allied health professionals will find that this is an invaluable tool in helping to deal with a broad spectrum of conditions encountered in the ICU. Represents a consensus of practice/standard of care in Australia/NZ, UK and Europe. Treatment guidelines are authoritative since they follow those that are Recommended/laid down by Professional societies. Comprehensive, covers all important areas of intensive care medicine. Provides a single resource that will cover everything that a user will need to know during the course of an ICU rotation. No need to refer to a larger textbook. Information on management and treatment of conditions is balanced by pathophysiological and pharmacological background. This is not just a "cook book" of procedures. It provides all of the essential information for candidates wishing to pass professional examinations. Covers the paediatric as well as the adult patient in the ICU. Provides quick access and practical guidance for all clinical scenarios. Extensive list of key references most taken from the last three years. Helps trainees and practitioners prepare for case conference/presentations. Addition of colour throughout to highlight summary boxes, tables, charts and flow diagrams.Will make key information more accessible, easier and faster to retrieve. Line drawings extensively re-done in colour throughout.Will improve the user’s understanding of the physiological processes under discussion. 5-10 Key points added at end of chapters. Will provide the user with a useful summary of the essential bottom line information. Pitfalls in treatment and management emphasized in each chapter.Providers the user with expert advice on practical issues that will be encountered on a day-to-day basis in the ICU. Includes the most current classification and “clinical scoring schemes. Keeps the user abreast of the latest developments in diagnosis and management.

Download or read book Human Interaction Emerging Technologies IHIET AI 2023 Artificial Intelligence Future Applications written by Tareq Ahram and Redha Taiar and published by AHFE Conference. This book was released on 2023-04-13 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: Human Interaction & Emerging Technologies: Artificial Intelligence & Future Applications Proceedings of the 9th International Conference on Human Interaction and Emerging Technologies, IHIET-AI 2023, April 13–15, 2023, Lausanne, Switzerland

Download or read book Human Interaction Emerging Technologies and Future Systems V written by Tareq Ahram and published by Springer Nature. This book was released on 2021-09-09 with total page 1316 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reports on research and developments in human–technology interaction. A special emphasis is given to human–computer interaction and its implementation for a wide range of purposes such as health care, aerospace, telecommunication, and education, among others. The human aspects are analyzed in detail. Timely studies on human-centered design, wearable technologies, social and affective computing, augmented, virtual and mixed reality simulation, human rehabilitation, and biomechanics represent the core of the book. Emerging technology applications in business, security, and infrastructure are also critically examined, thus offering a timely, scientifically grounded, but also professionally oriented snapshot of the current state of the field. The book gathers contributions presented at the 5th International Conference on Human Interaction and Emerging Technologies (IHIET 2021, August 27–29, 2021) and the 6th International Conference on Human Interaction and Emerging Technologies: Future Systems (IHIET-FS 2021, October 28–30, 2021), held virtually from France. It offers a timely survey and a practice-oriented reference guide to researchers and professionals dealing with design, systems engineering, and management of the next-generation technology and service systems.

Download or read book Industrial Ventilation Design Guidebook written by Howard D. Goodfellow and published by Academic Press. This book was released on 2021-06-04 with total page 745 pages. Available in PDF, EPUB and Kindle. Book excerpt: Industrial Ventilation Design Guidebook, Volume 2: Engineering Design and Applications brings together researchers, engineers (both design and plants), and scientists to develop a fundamental scientific understanding of ventilation to help engineers implement state-of-the-art ventilation and contaminant control technology. Now in two volumes, this reference contains extensive revisions and updates as well as a unique section on best practices for the following industrial sectors: Automotive; Cement; Biomass Gasifiers; Advanced Manufacturing; Industrial 4.0); Non-ferrous Smelters; Lime Kilns; Pulp and Paper; Semiconductor Industry; Steelmaking; Mining. - Brings together global researchers and engineers to solve complex ventilation and contaminant control problems using state-of-the-art design equations - Includes an expanded section on modeling and its practical applications based on recent advances in research - Features a new chapter on best practices for specific industrial sectors

Download or read book System Performance Evaluation and Design Guidelines for Displacement Ventilation written by Qingyan Chen and published by American Society of Heating Refrigerating and Air-Conditioning Engineers. This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents system performance evaluation, and includes a 10-step design guideline for displacement ventilation systems for U.S. buildings. These design guidelines present two important models: 1) to calculate the temperature difference between the head and the foot level of an occupant; and 2) one to determine the ventilation effectiveness at the breathing level.The book notes that: A displacement ventilation system can provide a thermally comfortable indoor environment at a high cooling load through careful design. The indoor air quality in a space with displacement ventilation is better if the contaminant sources are associates with the heat sources. The displacement ventilation system can also save energy but requires a separate heating system if it is applied to building perimeter zones. 6 x 9, soft cover.

Download or read book Pediatric and Neonatal Mechanical Ventilation written by Peter C. Rimensberger and published by Springer. This book was released on 2014-11-12 with total page 1584 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by outstanding authorities from all over the world, this comprehensive new textbook on pediatric and neonatal ventilation puts the focus on the effective delivery of respiratory support to children, infants and newborns. In the early chapters, developmental issues concerning the respiratory system are considered, physiological and mechanical principles are introduced and airway management and conventional and alternative ventilation techniques are discussed. Thereafter, the rational use of mechanical ventilation in various pediatric and neonatal pathologies is explained, with the emphasis on a practical step-by-step approach. Respiratory monitoring and safety issues in ventilated patients are considered in detail, and many other topics of interest to the bedside clinician are covered, including the ethics of withdrawal of respiratory support and educational issues. Throughout, the text is complemented by numerous illustrations and key information is clearly summarized in tables and lists.

Download or read book Building Ventilation written by David Etheridge and published by . This book was released on 1996-12-23 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book sets down the fundamentals of the theory and measurement of building ventilation and describes the various techniques for predicting and measuring ventilation. It addresses both envelope flows and internal air motion. The first part of the book is primarily concerned with physical descriptions and theoretical models: starting with an overview of the basic mechanisms and characteristics of envelope flows, it then addresses the treatment of the flow characteristics of individual openings and mathematical models for complete building envelopes. Theories for internal air motion are then discussed in detail: mechanisms of mass transport in terms of air motion and age distribution, primary air flows in isolation, resulting flows in enclosed spaces, and flows through large internal openings. The second part, concerned with measurement techniques both at full scale and at model scale, begins with techniques for determining flow characteristics of envelope openings. The use of tracer gases in the study of age distribution and ventilation efficiency is dealt with in detail. Scale modelling for investigating both envelope flows and internal motions is also addressed. The final chapter deals with Computational Fluid Dynamics, since one of its main applications is an alternative to conventional experimental techniques. Natural ventilation is re-emerging as an alternative to mechanical systems in some commercial buildings and both natural and mechanical ventilation are dealt with in detail.