Demand-controlled ventilation in educational buildings: Energy efficient but is it resilient?. (December 2022)

• Record Type: Journal Article
• Authors: Al Assaad, Douaa; Sengupta, Abantika; Breesch, Hilde
• Is Part Of: Building and environment. Volume 226(2022)
• Publication Date: 2022-12
• Subjects: Ventilation resilience -- Shocks -- Demand-controlled ventilation -- Indoor air quality -- Modelica model -- Educational building; Buildings -- Environmental engineering -- Periodicals; Building -- Research -- Periodicals; Constructions -- Technique de l'environnement -- Périodiques; Electronic journals; 696
• DOI: 10.1016/j.buildenv.2022.109778
• Languages: English
• ISSNs: 0360-1323

Abstract

Abstract: Educational buildings with smart ventilation are designed under known indoor and outdoor conditions. However, buildings can face sudden shocks that compromise IAQ. The characteristic that describes the extent to which buildings and their ventilation systems can maintain habitable conditions during shocks is "ventilation resilience". This study aims to assess the ventilation resilience of demand-controlled ventilation (DCV) in an existing educational building. To reach those aims, a Modelica model of the building was developed and experimentally validated. Shocks were classified into mechanical (MS), internal (IS), and outdoor (OS) and quantified using the degree of shock ( d o S ). Results showed that DCV had similar resilience to a constant air volume (CAV) regarding CO2, driving the DCV operation but 53–62% worse for VOCs. For CO2, for DCV and CAV, until d o S < 0.045, IS was 29.5% and 56.1% more critical than MS and OS. For d o S > 0.045, MS was the most critical, followed by IS and OS. For VOCs and CAV, until d o S < 0.08, IS was the most critical, followed by MS and OS. For d o S > 0.08, MS was the most critical, followed by IS and OS. For VOCs and DCV, MS was always the most critical. MS occurrence was critical during occupied periods only. IS occurrence had the same impact in similar classes with no prior build-up of contaminants. A morning OS was more critical than evening due to more occupancy. Graphical abstract: Image 1 Highlights: Ventilation resilience of DCV in an educational building assessed & compared to CAV. Shocks were classified into MS, IS & OS & quantified with the normalized index doS . Modelica model of the educational building was developed & validated experimentally. DCV has same resilience as CAV w.r.t CO2, driving the demand but 62% worse for VOCs. For CO2 & doS > 0.045 & for VOCs & any doS MS was most critical followed by IS & OS.