iCity 1: imaF – Natural ventilation

Maintaining comfortable indoor conditions in summer and winter is crucial for the well-being of the people who spend time in the building. Manual window ventilation is still a crucial measure for air exchange, requires the active intervention of users. The optimal time for window ventilation with regard to suitable environmental conditions is usually determined individually and purely intuitively. Since natural ventilation is highly dependent on outdoor conditions (especially wind and temperature conditions), control algorithms must be found that adapt to changing indoor and outdoor conditions and automatically open and close windows accordingly. Boundary conditions such as moisture transport, weather conditions, noise levels, fine dust pollution or pollen flight must be taken into account.imaF is an interdisciplinary project. Acoustic and thermal building physics is combined with electrical engineering and architectural issues.

Is it possible to ensure interior comfort with a double-layered window system and at the same time sufficiently prevent acoustic outside influences. Which active and passive sound insulation measures are suitable. Which control algorithms are appropriate for such window systems.

• CFD simulations are used to investigate air flows on the facade and through double-shell box-type windows - numerically and experimentally.
• In parallel, the second part of the project will develop control algorithms for wind-guided window ventilation. A communication between the window units is to be established.
• Based on this, suitable prototypes of windows will be searched for, equipped with control units and subjected to field tests.
• On the basis of the measurement results, optimizations are made and questions of architectural integration including fire, burglary and insect protection are answered.
• In a further part, acoustic investigations will be carried out in order to enable comfortable window ventilation even in inner-city environments with corresponding noise levels.

The objectives of this research project are to develop control algorithms for natural window ventilation, to implement these in the system and to improve natural ventilation by aerodynamic optimization. The acoustic properties of double-skin box-type windows should be oriented to those of a closed standard window.