tracer gas

Measurements of interzone airflow and movement of aerosol particles were carried out in an environmental chamber. SF tracer gas and oil-smoke particles were used for this work. A series of measurements were conducted to investigate the effect of parameters such as interzone temperature difference and size of opening on the flow of aerosol particles. The particle deposition rate on thesurfaces of the chamber together with algorithms for interzonal particle flow through the openings were determined. Results were compared with those obtained using the tracer-gas.

This paper is concerned with measurement of air and aerosol particle exchange efficiency in a single zone chamber. Aerosol particles and tracer gases were injected into the chamber and their concentrations were monitored as a funtion of time. The chamber was provided with supply and exhaust terminals which allowed various airflow and particle patterns (e.g. piston flow, displacement flow) to be investigated. The effect of airflow pattern on deposition rate of aerosol particles on the surfaces of the chamber was determined.

Workers in 'white collar' jobs continue to complain about air-quality' problems. Although there is a growing commercial interest in the measurement of gaseous and solid pollutants, there is no information on the effectiveness of New Zealand office ventilation systems. A set of baseline data is necessary to develop an understanding of the effectiveness with which air is provided in office spaces. This paper describes the results of preliminary ventilation effectiveness measurements made in mechanically ventilated spaces using a pulse tracer gas method.

Tracer-gas techniques are widely used for measurement of airflow in buildings and their accuracy depends critically on the uniformity of tracerlair mixing. However, tracer mixing is still an unsolved problem and the effect of many factors remains unclear. This paper presents a study of the effect on mixing of tracer species. The investigation concentrated on tracer mixing involved in the decay technique, which is the most widely used version of the tracer gas method.

The ventilation of a Swedish single family house is investigated by means of tracer gas and pressurization techniques. The ventilation flow plays an important role in this house as it enters through a dynamic loft insulation and exits via the crawl space. This design is said to give preheated and clean supply air, warm floors and good energy efficiency. But to meet these promises, it is essential that the air really flows in the intended paths. A single tracer gas technique is used to determine the air flow rates.

The work was concerned with measuring natural convection through a large horizontal opening of different sizes and shapes located between two rooms in a building. Airflow rates between the two rooms were measured using a tracer-gas decay technique. Room 1 was heated to various temperatures in the range 18°C to 33°C using thermostatically controlled heaters; room 2 was unheated. A multi-point sampling unit was used to collect tracer-gas samples from each room. The concentration of SF6 tracer was measured using an infra-red gas analyser.