Update on the IEA ECBCS Annex 35 project on hybrid ventilation systems. Discusses hybrid ventilation air flow process, climate data and air flow around buildings, pressure distribution on building surfaces, air flow characteristics of openings, air flow characteristics for other elements, air flow in and between rooms in a building, and air flow process for whole systems.

Discusses the new concept of hybrid ventilation, and the objectives of IEA ECBCS Annex 35 research in this area. Important areas of research are the development of control strategies, theoretical and experimental studies, the development of a decision tool, the implementation and demonstration of hybrid ventilation, reporting and expected results.