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. The heat and mass flow rates between the two rooms were calculated from the tracer-gas concentrations and temperature differences. The coefficient of discharge of the opening was found to be a function of the temperature difference between the two rooms. The mass flow rate was increased by increasing the area of the opening. The mass flow rate of a circular opening was in most cases higher than that of a square opening. The work also describes CFD modelling of natural convection through horizontal openings. Results were compared with values obtained from experiment.
An experimental and theoretical investigation of airflow through large horizontal openings.
![](https://www.aivc.org/sites/default/files/default_images/default_image_5.png)
Year:
1994
Bibliographic info:
15th AIVC Conference "The Role of Ventilation", Buxton, UK, 27-30 September 1994