This paper describes an analysis using the BRE Pollution Dispersion Wind Tunnel to estimate pollution concentration patterns on buildings in urban arrays due to local line sources of pollution, typical of vehicular traffic emissions. The experimental procedure involved measurements of both pressure and concentration patterns on building forms in urban arrays, intended to provide information on the ingestion of pollutants into buildings in urban areas.
The research community as well as the design and construction practice is spending a lot of efforts and investments in developing systems which optimise the energy use for achieving certain specified air flow rates. For example, improvements in efficiencies of 10 % in heat recovery systems would be considered as remarkable. At present, one observes a tremendous difference in the ventilation requirements in various countries as well as at the European level.
The ventilation requirements for decontamination are normally determined with a static calculation method. In some cases, the pollutant emission is intermittent, for example in the car park of an office building, where all the cars enter and leave the place nearly at the same time. Generally, in such a case, the volume of the garage is large, consequently the time constant of the system has a high value. So a static approach would no longer stay accurate and a dynamic evaluation is needed.
This paper presents the results of a research program that was conducted for ASHRAE by TRC- Environmental Consultants, Inc. The purpose of the study was to provide information on the effectiveness of existing ASHRAE ventilation guidelines for maintaining acceptable air pollutant levels and to develop a methodology for including economic utilization of energy in the consideration of future guidelines.
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