Ventilation systems perform a number of tasks. They must remove contamination/pollution, they act as heat/cold transporters and they must create a satisfactory room climate without causing draughts. States that users must be aware of the limitations of ventilation systems and that ventilation systems are not able to carry out all tasks completely satisfactorily. Compares the efficiencies of displacement and mixing systems and gives guide values for temperature differences between room air and supply air for office and industrial applications.
Ventilation rates were measured in nine office buildings using an automated tracer gas measuring system. The buildings range in size from a two-storey federal building with a floor area of about 20,000 ft2 (1900 m2) to a 26-storey office building with a floor area of 700,000 ft2 (65,000 m2). The ventilation rates were measured for about 100 hours in each building over a range of weather conditions. The results are presented and examined for variation with time and weather. In most cases, the ventilation rate of a building is similar for hot and cold weather.
Ventilation by displacement is described in terms of ventilation efficiency and quantified by means of a two-zone flow and diffusion model. The practical procedure is by means of adequate diffusers firstly, to 'hit' the persons with the ventilation air and secondly, to displace both air and contaminants out of the zone of occupation and avoid recirculation. This procedure has a firmbasis in the research work on ventilation efficiency that is carried out inNorway and Sweden during the last years as well as in current theory practice.
Effectiveness of ventilation as a major means of controlling indoor air quality was evaluated by correlating concentrations of gaseous (CO and CO2) and particulate (total) pollutants with two ventilation parameters. Pollutants are differently af
The tracer technique can be used in ventilation and contaminant spreading investigations. We have chosen sulphur hexafluoride. We have constructed aspecific instrumentation to perform indoor tests. All components are portable and battery operable. We use generators with remotely controlled flow, real-time chromatographs as analysers, continuous SF6 monitors and field-use calibrators. We have performed numerous tests, in the nuclear industry (Laboratories, reprocessing facilities and PWR), in conventional industries and in hospitals.
Several papers discussing ventilation efficiency, effective industrial ventilation, the positioning of ventilation inlets and outlets, displacement ventilation and other applications of the concept of ventilation efficiency.
Discusses the concept of ventilation efficiency. Sources of moisture production in residential buildings are given, and the minimum ventilation requirements for moisture removal are presented for a typical 3 person dwelling for various outdoor temperatures.
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