Analysis of parameters affecting the internal environment of a naturally ventilated auditorium.

A programme of work involving the measurement of ventilation rates, air velocities and temperatures has been completed within a naturally ventilated auditorium in the Queens Building, De Montfort University. Measurements have been recorded for 'winter', 'mid-season' and 'summer' conditions, and average occupancy levels. Measurements carried out in 'winter' and 'mid-season' indicate that the predominant ventilation driving force is the stack effect However, current control settings of fresh air inlets allow too great a free area to be produced, which causes high room air velocities with associated low temperatures, resulting in high discomfort levels for occupants seated in line with external openings. Results for 'summer' external conditions on particular dates indicate that ventilation rates are driven largely by wind-induced effects, which can be much higher than buoyancy driven flows. Internal ceiling and wall surface temperatures show little variations with time, owing to the heavyweight nature of the building structure and its exposed areas.