Ventilating Cities

The majority of the world’s population live in environments with artificially weakened wind as buildings in urban areas form wind-breaks and reduce wind speeds. Anthropogenic heat is also generated and during the summer dense urban areas suffer from the urban heat island effect, a known urban climate problem. This book discusses how to evaluate the urban wind environment, including ventilation performance and thermal comfort. This book is organized in two parts; Wind Environment and the Urban Environment and Criteria for Assessing Breeze Environments. It includes chapters on sea breeze in urban areas; thermal adaptation and the effect of wind on thermal comfort; health risk of exposures; pollutant transport in dense urban areas; legal regulations for urban ventilation and new criteria for assessing the local wind environment. Keywords: urban wind environments, urban heat island, urban climate, land use change, thermal comfort, risk assessment, urban air pollution, urban ventilation

This book presents the necessary fundamental knowledge in the research, development, design, selection, and application of desiccant heating, ventilating, and air-conditioning systems. It covers the established installations in different climatic conditions and building types. In addition, advanced performance evaluation techniques are presented, covering thermodynamic, economic, and environmental aspects. Hence, the book is an important resource for undergraduate and graduate students, design and installation engineers, researchers and scientists, building owners and occupants, and energy and environmental policy makers.

Throughout the world, there is an increasing interest in ecological design of buildings, and natural ventilation has proved to be the most efficient low-energy cooling technique. Its practical application, however, is hindered by the lack of information on the complex relationship between the building and its urban environment. In this book, a team of experts provide first-hand information and tools on the efficient use of natural ventilation in urban buildings. Key design principles are explained, enabling readers to decide on the best solution for natural ventilation of buildings, taking into account climate and urban context. In the initial sketches, architects need answers to open problems such as 'what kind of solution to adopt' and 'how to modify existing strategies to exploit the potential of the site'. This book formalizes the multi-criteria analysis of candidate solutions based on quantitative and qualitative estimation of the driving forces (wind and buoyancy), as well as of the barriers induced by the urban environment (wind speed reduction, noise and pollution) and gives a methodology for optimal design of openings. The book is accompanied by a FREE CD, containing software for assessing the potential of a given site, estimating wind speed and dimensioning the openings for natural ventilation. The methodologies and tools are tested, self-contained and user friendly. About the editors The editors, Cristian Ghiaus and Francis Allard, are affiliated with the University of La Rochelle, France. The authors and reviewers combine expertise from universities, research institutions and industry in Belgium, France, Great Britain, Greece, Portugal and Switzerland.

This book presents selected papers from the 11th International Symposium on Heating, Ventilation and Air Conditioning (ISHVAC 2019), with a focus on HVAC techniques for improving indoor environment quality and the energy efficiency of heating and cooling systems. Presenting inspiration for implementing more efficient and safer HVAC systems, the book is a valuable resource for academic researchers, engineers in industry, and government regulators.

This book contains twenty-one original papers and one review paper published by internationally recognized experts in the Atmosphere Special Issue "Recent Advances in Urban Ventilation Assessment and Flow Modelling", years 2017–2019. The Special Issue includes contributions on recent experimental and modelling works, techniques, and developments mainly tailored to the assessment of urban ventilation on flow and pollutant dispersion in cities. The study of ventilation is of critical importance, as it addresses the capacity with which a built urban structure is capable of replacing the polluted air with ambient fresh air. Here, ventilation is recognized as a transport process that improves local microclimate and air quality and closely relates to the term “breathability”. The efficiency with which street canyon ventilation occurs depends on the complex interaction between the atmospheric boundary layer flow and the local urban morphology. The individual contributions to this Issue are summarized and categorized into four broad topics: (1) outdoor ventilation efficiency and application/development of ventilation indices, (2) relationship between indoor and outdoor ventilation, (3) effects of urban morphology and obstacles to ventilation, and (4) ventilation modelling in realistic urban districts. The results and approaches presented and proposed will be of great interest to experimentalists and modelers, and may constitute a starting point for the improvement of numerical simulations of flow and pollutant dispersion in the urban environment, for the development of simulation tools, and for the implementation of mitigation strategies.