mixed-mode ventilation

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.

Mixed-Mode ventilation is an innovative approach that maximizes the use of natural ventilation and uses supplementary mechanical cooling only when strictly required. The application of Mixed-Mode ventilation in severe arid climates and its integration with other passive cooling strategies is very challenging and has not been systematically studied. The paper will present an evaluation of the performance of different Mixed-Mode cooling strategies for a single-zone office space in four main arid cities that represent the diversity in arid climates.

The buildings sector offers the greatest potential for cost-effective reductions in greenhouse gasemissions out of all the sectors examined by the Intergovernmental Panel on Climate Change.However that potential was based purely on technical measures applied to existing buildings and newconstruction. It is becoming increasingly clear that non-technical options involving building occupantcomfort, culture and behaviour will also need to be implemented in order to stabilise atmosphericconcentrations of CO2 within a useful timeframe.