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.

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.

Simulation is proving more and more important in building physics. Programs of different levels of complexity are today available for researchers and designers to model and plan buildings. But the accuracy of the output is not usually provided as a common result. This paper is a short summary of a dissertation [1] focused on the accuracy of the simulation outputs as a function of the accuracy of the input parameters.

A series of laboratory experiments are described which investigated the effect of surface roughness on the air flow characteristics of simple, straight-through, no-bend cracks with smooth and rough internal surfaces. Thecrack lengths, in the direction of flow, were 50.8mm and 76.2mm. For the rough cracks the roughness was simulated with two different grades of commercially available emery-cloth (grade 60 and 100). The effect of roughness on the reduction of air flowing through a crack is also discussed.

One important aim for the development of new air conditioning systems is the reduction of the total energy consumption. This can be reached by separation of cooling and ventilation in air conditioning systems, because it is more effective to transport energy by using water systems instead of air to deliver cooling energy to the consumers. This strategic was the base for the development of several chilled ceilling systems during the last years, so that at present there are many different systems on the market.

This paper reports on ventilation measurements taken beneath a suspended timber floor of a BRE/DoE energy and environment test house. Sulphur hexafluoride was introduced into the subfloor void at a constant rate and the resulting concentration measured. Wind speed, wind direction, and internal, external and subfloor temperatures were also recorded. A range of air brick locations were used for each run which lasted two to three days.

A study has been undertaken to (1) evaluate airtightness in recent construction dwellings in New York State, (2) evaluate the effectiveness of various strategies in providing adequate ventilation, and (3) study the use of various ventilation options by residential builders and heating, ventilation and air-conditioning (HVAC) contractors.

Residential ventilation has at least two energy penalties that must be considered when addressing the ventilation levels recommended in ASHRAE Standard 62. Energy is required to heat the fresh outside air used for ventilation. In cold climates with high heating costs, an air-to-air heat exchanger can lessen the operating expense. Energy is needed for the fan motor used to introduce fresh outside air andlor to exhaust stale indoor air.

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.