Indoor air quality and thermal comfort optimization in classrooms developing an automatic system for windows opening and closing

• Published in: Energy and buildings Vol. 139; pp. 732 - 746
• Main Authors: Stazi, Francesca, Naspi, Federica, Ulpiani, Giulia, Di Perna, Costanzo
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.03.2017; Elsevier BV
• Subjects: Academic achievement; Adaptive actions; Adaptive algorithms; Adaptive control; Air quality; Automatic control; Carbon dioxide; Classrooms; Control theory; Environmental conditions; Indoor air pollution; Indoor air quality; Indoor environments; Natural ventilation; Optimization; School building automation; School environment; Students; Thermal comfort; User satisfaction; Window opening; School building automation; Thermal comfort; Window opening; Adaptive actions; Natural ventilation; Indoor air quality
• ISSN: 0378-7788; 1872-6178
• DOI: 10.1016/j.enbuild.2017.01.017

•Environmental parameters triggering users’ actions on windows were assessed.•An automatic system for windows opening was developed to achieve IEQ in a classroom.•The system was driven by an adjusted version of Humphreys’ adaptive algorithm.•The algorithm was adapted including CO2 concentration and reducing the dead band.•The system guarantees low CO2 levels, thermal comfort and users satisfaction. Thermal comfort and indoor air quality in school classrooms are essential requirements to promote students’ productivity and reduce health symptoms. This paper presents the development of an automatic system for window openings, based on thermal comfort and indoor air quality correlations. The research was carried out in two adjacent classrooms. The initial phase aimed at assessing environmental conditions in classrooms, testing objective and subjective comfort models and establishing trigger parameters for window opening events; the second phase regarded the implementation of an adaptive control algorithm in an automatic system piloting windows with the aim of maintaining a satisfactory environment both in terms of IAQ and thermal comfort. The main results show that: (1) the IAQ is a relevant issue in school classrooms, because students usually suffer high CO2 levels; (2) the stronger driving force for undertaking adaptive actions is thermal comfort, while the need to improve the air quality is a secondary constraint; (3) the mechanized system ensures a good quality in terms of IAQ, thermal comfort and users’ satisfaction.