The National Institute of Standards and Technology (NIST) is conducting a study on the indoor air quality (IAQ) impacts and engineering solutions related to the transport of pollutants from attached garages to residential living spaces. Natural or fan-induced pressure differences across air leakage paths in house-garage (HG) interfaces can result in the transport of the contaminants generated in garages into adjacent living spaces.
The mechanism of cross ventilation is dealt with in this paper. The results are obtained by a combination of wind tunnel studies and CFD predictions using a Reynolds stress model as the turbulence model. All buildings have been exposed to a uniform velocity field and therefore the reference flow rate for an opening is equal to the velocity multiplied by the opening area. The openings were located at or close to the position of the stagnation point on the corresponding sealed building.
The present paper aims at investigating the indoor air quality in fifteen school buildings located in the greater Athens area. Experimental investigations were performed in fifteen different school classrooms and the concentration levels of various pollutants such as CO2, CO, TVOC, HCHO, and radon, were measured. Moreover, the experimental investigation included measurements of several environmental parameters such as temperature, relative humidity and air velocity inside each classroom, while ventilation was examined by estimating the air changes using the tracer gas technique.
The efficiency of an exhaust system is especially important in a kitchen environment in which the exhaust is located at ceiling level. The capture efficiency of the total system must be guaranteed so that the spread of impurities throughout the kitchen is prevented. A capture efficiency model is derived and it is used to estimate the efficiency of a ventilated ceiling.
Terrorist attack in buildings by chemical and biological agents (CBAs) is a reality in our lives. This study applies computational fluid dynamics (CFD) to predict CBA dispersion in an office building in order to find the best locations for CBA sensors and to develop effective ventilation systems to protect building occupants in case of indoor CBA releases. It is found that the CFD is a useful tool for such an application, while some challenges remain.
The behaviour of particles in air flow is important for identifying those in various locations in ventilated space. The main reason for this study is to propose a new modelling concept to determine a realistic distribution of particles of different sizes in a space. The goal for this investigation is to divide particles into groups according to their behaviour in air and to improve the existing settling model. The growth of particle aerodynamic diameter in higher relative humidity is also presented.
This paper examines the performance of a large new multi storey building which relies exclusively on natural ventilation. The building is designed to provide the main library and associated functions for Coventry University. The research outlines the sophisticated control systems necessary for such a building and provides an analysis of the strategies and techniques required for its implementation. A case study of user satisfaction demonstrates that a large naturally ventilated building can provide a pleasant comfortable environment for occupants.
Data exchange is the process by which information is transferred between the engineer and software and between one piece of software and another. Building and plant simulation involves handling large data sets describing constructional details, system components and reference data. The time required to prepare and check the data is significant and is one obstruction to the widespread use of simulation within the design process. Links between drafting systems and analytical tools offer an obvious way to speed up the process and reduce input errors.
Since the oil crisis of the seventies, the interest given to buildings physics, indoor climate and energy use has strongly increased. The building envelope and HVAC systems in modern buildings are often completely different from those typically found in buildings of the sixties and seventies. In general, we often consider the quality of todays buildings substantially higher. To what extent is this impression of improved quality fact or fiction? Is it valid for all technologies and is there a substantial improvement in quality of the indoor climate?
The aim of this study is to evaluate the efficiency of different ventilation strategies for a house and fora subfloor void to reduce the radon concentration level of the indoor air.A steady-state analytical ventilation model is derived to estimate the indoor air radon concentration inhouses on ground floor or with subfloor voids.
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