Mitigation of airborne contaminants dispersion in an educational building and investigate its impacts on indoor air quality and energy performance

Abstract

In today's modern world, people spend most of their time inside buildings, highlighting the importance of indoor air quality (IAQ) and providing clean air to the occupants. In this regard, a simple educational building is modeled using CONTAM-EnergyPlus co-simulation to investigate IAQ enhancement strategies and their role in the building's energy performance. Three contaminants, including CO2, PM2.5, and SARS-CoV-2, are considered to be generated from various sources. The occupants generate CO2, a source of PM2.5 is assumed in the lunchroom to represent cooking activities, and a person who sheds SARS-CoV-2 moves around the zones. The main goal of this study is to apply various pollutant mitigation methods to the model, such as increasing ventilation rate and outdoor air (OA) percentage, natural ventilation, installing filters and air cleaners, and UVGI lights. Then, their performance and impact on the defined contaminants are studied individually and in combination.In this regard, a scenario with 80% outdoor air (OA) and 100% ventilation rate has been shown to be effective in reducing all three contaminants' concentrations to acceptable levels in most zones, but this results in 50% higher energy consumption compared to the model with no outdoor air. However, to achieve a safe level of PM2.5 in the lunchroom, a combination of all the strategies presented in the (0.8OA+1Vent+NatVent+all) scenario is required. Furthermore, HEPA air cleaners are more effective in diluting contaminants in all zones than UVGI lights and MERV 13 filters. Additionally, this study has shown that HVAC systems operating with little or no outside air can increase the risk of pollutants being transmitted between adjacent zones through the ducts, making it necessary to install in-duct filters.

Enhancing Indoor Air Quality and Regulatory Compliance: An In-Depth Comparative Study on Ventilation Strategies and Their Impact on SARS-CoV-2 Transmission Risk

“…This approach demonstrated a significant impact on reducing the P in the rooms with the worst conditions, leading to a 28% to 50% reduction in P mean . In addition to these measures, strategies to further mitigate transmission risk include the use of face masks and the installation of in-duct MERV filters, where air recirculates in the ventilation system, which was addressed in [9,15,21].…”

“…However, in a mechanically ventilated environment, occupants can still affect their level of safety with their actions. For instance, if the ventilation rate proves inadequate, occupants can take protective measures, such as wearing masks or practicing social distancing, similar to the measures taken during the COVID-19 pandemic to mitigate the risk of various diseases [9]. Moreover, ensuring sufficient mechanical ventilation in buildings becomes more important, particularly in winter.…”

Multi-Zonal Analysis of Indoor Air Quality in a Higher Educational Building in the UK

“…Another aspect that can be addressed in the future is comparing the cost and environmental footprint of the recommended strategies. Furthermore, their impact on energy consumption is investigated in the author's previous paper [24], which was conducted in another case study. Including such comparative analyses would enhance the overall understanding of IAQ improvement strategies.…”

“…The previous study by the authors [24] provides a comprehensive description of the simulation process and the modeling methodology employed in the CONTAM.…”