Ventilation of Dutch schools; an integral approach to improve design

1 Introduction The status quo of school ventilation in the Netherlands is presented (e.g. average CO2 levels in schools, quality of ventilation). In the Netherlands the most popular ventilation system for schools is exhaust-only ventilation with natural supply ventilation by means of air grilles or windows combined with convector of panel heating. 2 METHODOLOGY In a first study the goal was to evaluate the IAQ performance of exhaust-only ventilation systems. In 5 Dutch schools measurements were conducted in the heating season for a period of around 7 days. These measurements included: IAQ (CO2), thermal comfort, airflow and outdoor conditions. A logbook and questionnaires obtained information about use of ventilation facilities and satisfaction of users. In a next study in 9 schools were measurements done during one day. In another research project 11 schools were examined. In a final study another 6 schools were again measured during a week. The goal of these studies was to evaluate the performance of exhaust-only ventilation systems. The performance was rather disappointed, as there were measured CO2 concentrations of up to 4700 ppm, there were a lot of problems and insufficient situations found. Next measurements were done in 3 schools innovative hybrid ventilation systems and thermal activated building systems (TABS). 3 RESULTS During the next years different master students together with the staff of Technische Universiteit Eindhoven were researching different aspects of the problem and trying to find solutions. A new integrated approach to design adequate solutions for ventilation of school buildings was developed. Integral design is meant to overcome the difficulties of design team cooperation, by providing methods that make it possible to communicate the consequences of design moves on areas such as construction, costs, life cycle and indoor climate at early design stages, between the different disciplines. First design results are described in the paper.