user behaviour

Mixed-mode ventilation uses intelligent switching between natural and (partly) mechanical ventilation modes to find the best possible balance between indoor air quality, user comfort and energy consumption. It applies demand-control at the level of the operating mode depending on the constraints imposed by the building, its users and its surroundings. Although mixed-mode ventilation is said to have the potential to achieve a comfortable and healthy indoor environment while achieving significant energy savings, it is rarely used in practice.

To gain access to information on energy use in office buildings, the German Federal Ministry forEconomy launched an intensive research and demonstration programme in 1995. In advance of theEU energy performance directive a limited primary energy coefficient of about 100 kWh m-2a-1 as agoal for the complete building services technology was postulated (HVAC + lighting) for alldemonstration buildings. A further condition was that active cooling be avoided.