The influence of air supply and exhaust locations on ventilation efficiency and contaminant exposures in rooms.

An efficient ventilation system is characterised by a well-organised and turbulence-controlled airstream that rapidly corrects disturbances in air quality and thermal comfort in the ventilated space.Air supply and exhaust conditions are investigated here in order to find stable flow conditions andan efficient elimination of both gas and solid phase contaminants. Heat and thermal comfortrequirements are also included. Existing displacement ventilation installations cannot alwaysmeet the current requirements of good indoor air quality, thermal comfort and energy use, andimproved solutions are therefore needed. It is shown here that the conditions of both air supplyand exhaust are critical to the overall ventilation effectiveness in a room. Personal exposures havebeen studied by computer simulations. A new numerical method has enabled assessments ofexposures to particle contaminants, which are extremely difficult to measure in practice.