Hardware and controls for natural ventilation cooling.

This research is part of project NATVENT (TM), a concerted action of nine institutions ofseven European countries under the Joule-3 program. It aims to open the barriers that blocks theuse of natural ventilation systems in office buildings in cold and moderate climate zones.Natural night-time ventilation cooling is a very effective means to remove the heat,accumulated in the building fabrics during office hours. Moreover, it requires no energy at all.Cooling with natural ventilation has it limits; more than 6 air changes per hour have no morecooling effect. So precautions have to be taken to reduce the heat gain during the day by limitingthe glass area to approximately 40% and using effective sun shading devices. The internal heatload is also limited to 25 W . m^-2. Hardware for night cooling are the traditional types ofwindows and trickle ventilators. To obtain the most benefit of night cooling, automatic controlis essential. For this the control strategies is of utmost importance. Specially for night-timeventilation cooling developed control strategies are incorporated in the predictive control,cooling day control, setpoint control, slab temperature control, degree hour control.