The project is an international cooperation within the International Energy Agency, which is managed by Aalborg University. Research groups from 12 countries are involved in the project. The aim of the project is to further the dissemination of hybrid ventilation in office buildings to improve the theoretical and experimental basis for the design of hybrid ventilation solutions, to improve existing design methods and develop strategies and control principles for hybrid ventilation in office buildings, which ensure optimal utilization of the natural driving forces, and which at the same time ensure that the requirements for air quality, temperature level and energy consumption are fulfilled. The project includes theoretical calculations of energy and air flow conditions in office buildings with hybrid ventilation as well as laboratory tests of elements of the ventilation system and measurements of function and energy consumption of plants in existing office buildings. For more info, see http://hybvent.civil.aau.dk. The project is funded by the Danish Energy Authority.