BRE has developed a new technique for measuring time-averaged ventilation rates in occupied buildings using a perfluorocarbon tracer gas. It was conceived as a way of solving the problems which arise when conventional tracer gas techniques are used in large or multi-roomed buildings. Potentially, the new technique will allow routine performance monitoring of both natural ventilation and forced air supply systems, thereby helping users to save energy and to meet the health, safety and comfort requirements of the building's occupants.
Residents completed a questionnaire survey assessing indoor environment and residents' behavior (i.e. when they opened windows/doors, when they operated air conditioners, and so on) during the period of ventilation measurement. The purpose of this study is to measure the ventilation rate in occupied dwellings in Kagoshima City, located in the southern part of Japan, using the tracer gas method and to investigate the relationship between the occupants' behavior in each dwelling and the energy consumption for air conditioning during the summer period.
The aim of the study was to investigate the operation of different types of ventilation in placesconstructed underground and ground level; the effect of ventilation on indoor radon levels wasalso examined. Air exchange rates and radon concentrations were measured in underground(n=73) and ground level (n=64) workplaces. Air exchange rates, designed exhaust ventilationflows, ventilation rates per person and area were sigmficantly higher in underground placesthan places constructed on the ground level.
In principle, the results of carbon dioxide monitoring can be used to evaluate building ventilation rates and provide an indication of perceived indoor air quality. Here we review current knowledge about the use of metabolically-produced co2 in indoor air quality evaluation and control.
Computational fluid dynamics (CPD) modelling is increasingly being used as a tool for predicting ventilation rates and air flow patterns as part of the building design process. The potential benefits of this form of modelling are that designs can be optimised to make the most efficient use of ventilation, and so to increase air quality and decrease energy use. Although CFD has shown itself to be a powerful tool in the nuclear, aeronautical and electronics industries for over two decades, its reputation has been built on extensive work specific to those fields.
Real-time ventilation and infiltration measurements were made on ten single-family homes. Seven of these had crawlspaces and were in the Pacific Northwest Two had daylight basements and were also in the Pacific Northwest. The other is an energy efficient demonstration "smart" house built in Rocklin, CA, and was built on a crawlspace. All of the homes were tested under heating season conditions. The home in Rocklin was also tested under cooling conditions. Each house was divided into multiple zones, including buffer spaces, and each test period lasted about a week.
The cabin of a commercial aircraft is a high density environment in which occupants are potentially at risk of airborne transmission of Mycobacterium tuberculosis. Trans-continental and trans-oceanic flights are routinely undertaken with hundreds of passengers. During these long flights there is an increased duration of potential exposure to airborne contaminants and bioeffluents. This paper determines a "worst case" risk of tuberculosis infection for the passengers and flight attendants based upon typical design and ventilation parameters of a commercial aircraft.