Application of CFD to Predict and Control Chemical and Biological Agent Dispersion in Buildings

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.

Characteristics of Particles and their Behaviour in Ventilation Air

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.

Comfort and Acoustic Monitoring in a Large Naturally Ventilated Technically Advanced Building

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 for Thermal Modelling and Ventilation Simulation

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.

Designing Thermal Mass in Naturally Ventilated Buildings

According to its location, thermal mass can be approximately classified into two types: external and internal. Internal thermal mass, such as furniture and purpose-built internal concrete partitions, does not expose to ambient temperature directly, while external thermal mass, such as walls and roofs, expose directly to ambient temperature variation. A virtual sphere method for modelling thermal mass is introduced and its application in building thermal mass design is discussed.

Developments in Wind Tunnel Studies for Estimating the Cross Ventilation Potential for a Low-Rise Building in a Built-Up Area

To accurately estimate the natural wind driven ventilation potential of a specific low rise building in a densely shielded or built-up area under local wind conditions, it is necessary to have site wind frequency data, pressure coefficient data, details about the windward and leeward openings of the building and the data related to building design. This paper summarises the appropriate data and discusses how to obtain these in order to estimate the natural cross ventilation potential of such a low-rise building.

Effect of Screening Solar Chimneys on Induced Air Flow Rate

This paper reports on a field investigation of the effect of screening on the induced flow rate in solar chimneys. The solar chimney considered here was a roof solar collector (RSC). It is composed of CPAC monier concrete tiles, an air gap and gypsum board. Two RSC units were integrated into the south-facing roof of a centre single room house of 25 m3 volume. Different types of screening were considered, namely: mosquito net, square net, metal grille and nylon filter.

Effectiveness of Purging in an Air-Conditioned Office Building in Singapore

This paper investigates the effectiveness of a Purging System in a high-rise office building in Singapore with the aim of improving indoor air quality. The study initially adopts a continuous monitoring concept to investigate the impact of a daily purging operation on pollutant concentration levels at the low, middle and high floors of the office building. Pollutants investigated include formaldehyde, carbon dioxide, carbon monoxide and total volatile organic compounds (TVOC).

Experimental Investigation of Three Types of Clean Room Diffusers using Particle Image Velocimetry and Laser Doppler Velocimetry Techniques

The main purpose of this paper is to evaluate the main fluid mechanics parameters in the exit region of three different terminal systems commonly used for controlled environments such as clean rooms or operating theatres. Three different types of diffuser were tested i.e. a diffuser grid, a square ceiling diffuser and a swirling radial discharge diffuser. The paper presents results obtained experimentally which were carried out in order to study the flow characteristics of isothermal jets issuing from such devices.

Flow Network Model based on Power Balance as Applied to Cross-Ventilation

This paper reviews the flow network model based on power balance as applied to wind-induced cross ventilation in a residential building. The characteristics of wind-induced cross-ventilation with open windows in buildings are different from those of air infiltration through cracks in walls. The features of the velocity and pressure distributions are apparently different. In cross-ventilation, it seems that a kind of stream tube is formed through the building.

Pages