Air quality measured in a classroom served by roof mounted natural ventilation windcatchers

This study examines air quality measured in two classroomsin a UK school, which uses two different forms of natural ventilation, over an eight month period. The first classroom is an internal room that contains a top-down natural ventilation system known as a Windcatcher.The room also has a separate mechanical extract fan. The second classroom is ventilated using windows and doors that open to the outside. This study focuses on measuring the performance of a Windcatcher and reviews its potential to replace ventilation provided by conventional windows. Potential benefits of Windcatchersinclude the ability to provide night cooling without posing a security risks, and daytime ventilation without relying upon opening windows. The study will examine Windcatcher performance in terms of air qualitydelivered in the first room, and then compare results with measurements obtained for a room that uses conventionalopening windows. The study will also review the effectiveness of Windcatchers in meeting the regulatorystandards for naturally ventilated classrooms, as set out by the UK Government.The air quality measurements reported demonstrate that the classroom utilising a Windcatcher was able to meet the UK Government standards for carbon dioxide and temperature, while the classroom relying solely on windowsfailed to meet the carbon dioxide requirements. Furthermore,the study demonstrates that Windcatchers providesignificant night cooling and increase air exchange rates. Windcatchers do, therefore, have a significant role to play in meeting ventilation requirements in schools.