Case Study – CO2 Dashboards for Ventilation Monitoring in Schools

Figure 1

Ruth Kerrigan, Chief Operating Officer, IES

As part of the AMBER (Assessment Methodology for Building Energy Rating) project, IES has developed a monitoring and control system for ensuring adequate ventilation in spaces to minimise the risk and spread of COVID-19. The solution employs a simple set up with a CO2 monitor and a dashboard placed in each classroom. The dashboard has been specifically designed to engage with students so that they can prompt their teacher to open a door or window as necessary, or take this action for themselves.

Key Facts:

  • Dashboard deployed in number of schools in Ireland and proven to reduce CO2 peaks by more than 50%. Reducing the time where CO2 levels are over 1,500ppm from hours to minutes
  • By ensuring the CO2 remains below a given threshold, e.g. 1,000ppm, this ensures adequate ventilation in the classroom, which minimises the impact of the spread of COVID-19
  • Advantage of IES solution compared to standard CO2 monitor is bright display, large screen and engaging avatar to prompt the students to take an action 
  • Dashboard enables remote monitoring of CO2 data so that a report can be provided to the school on the effectiveness of the solution and whether any further action needs to be taken
  • Educational for school children to learn about CO2 and its impacts on their health

IES and Trinity College Dublin have been working together since 2018 on the SEAI funded R&D project, AMBER (Assessment Methodology for Building Energy Rating). The project was designed to provide a set of guidelines to minimise the performance gap in A-rated buildings, complemented by design best practices and user comfort and wellness recommendations. Within this there were two core aspects to the project: i) to examine the performance gap between the design and operation of the A-rated building and ii) to examine the impact on Indoor Air Quality (IAQ) of the A-Rated building.

Within IAQ, the focus was on measuring temperature, CO2 and relative humidity. Two sets of buildings were considered, domestic and non-domestic. Within non-domestic, we largely examined schools, with a few healthcare buildings and one commercial office.

Halfway through the project, the COVID-19 pandemic occurred and this had a significant impact on the results and outcomes from the project as now IAQ became a much more serious issue within buildings, particularly with respect to the importance of ventilation. The project had already identified the importance of monitoring CO2 and had highlighted a number of serious issues with respect to the CO2 levels in both homes and schools. In some instances, the CO2 levels in schools were rising to over 6,000ppm; CO2 typically should stay less than 1,000ppm and high levels of CO2 can cause fatigue and affect concentration.

Based on this, IES commissioned the design of a dashboard to target schools, and children in particular, to take actions when the CO2 levels went too high, as shown in Figure 1.  We worked with an environmental engineer who also had a background in behavioural science to ensure that the dashboard was engaging for children and would enable an action to open a door or window, when the CO2 level went over 1,000ppm.

A simpler method could have been to put a CO2 sensor with a number display on the wall in the room, however there was a strong risk that this would be ignored or not seen due to its size. As the dashboard for the classroom was designed specifically to engage with children, it was felt that this risk would be significantly reduced. Another key advantage of the solution is that the CO2 data can be monitored remotely and if there are classrooms where no actions are being taken on a regular basis, this information can be given back to the schools in the form of a report.

The dashboard was deployed successfully in four schools; three secondary (A-Rated) and one primary (non A-Rated). It was shown to be highly successful in reducing the CO2 levels in the classroom and the children found the dashboard engaging and also educational, as they were also able to learn about CO2, what causes it and how it affects our environment, e.g. global warming.

For example, Figure 2 shows the CO2 levels in ‘Classroom A’ in the non A-Rated primary school prior to the dashboard being installed. Figure 3, shows the CO2 levels in the same classroom after the dashboard has been introduced. It can be seen in Figure 2 that the CO2 has a peak of approx. 3,000ppm when there is no dashboard, and the CO2 levels stay above 1,500ppm for between 90 minutes and three hours. As shown in Figure 3, the peak is then reduced by 50% to approx. 1,500ppm once the dashboard has been introduced and the peak only occurs for a short period of time with the CO2 levels mainly staying below 1,000ppm.

It is important to also note that this classroom was actually an outdoor pre-fab in the older non A-Rated school. CO2 sensors in the main school showed levels well below the 1,000ppm threshold as the school was old and hence leaky, which would ensure good air flow from a ventilation perspective. Four pre-fabs in the school were monitored and three out of the four all showed high levels of CO2, the only difference in the pre-fab with low CO2 levels was that the teacher left the windows open on a consistent basis.

While the project began by looking at the impact of the A-Rated building on IAQ, and uncovered some serious issues with respect to the CO2 levels in classrooms, it was quickly realised that this method could also be used to monitor and control the ventilation levels in classrooms with respect to the spread of COVID-19.  This has been consolidated recently by John Wenger of the UCC school of chemistry who has been widely reporting that CO2 monitors should be used to monitor the airflow through buildings, i.e. if the CO2 is rising, ventilation needs to be added to the space, to dissipate the CO2. As such, CO2 can be used to monitor the airflow in the room and hence how good is the ventilation in the space.

Figure 4

For example, Figure 4 illustrates the CO2 in ‘Classroom B’ in an A-Rated secondary school in February 2020 (left hand image) and October 2020 (right hand image). In February 2020, the CO2 in this particular classroom was reaching peaks of 6,000ppm and for a large portion of the time, the CO2 is greater than 1,500ppm. In October 2020, due to the COVID-19 pandemic, the schools were requested to keep all windows open with the result that the CO2 remained below 1,000ppm on any given day. This presented clear evidence of the impact of ventilation on CO2 in classrooms and hence how CO2 could be used to monitor ventilation.

IES and Trinity have already tested this solution, not only ensuring good IAQ in classrooms but that it can also be used to control the ventilation in the space and prompt the room occupants to take an action when the CO2 levels reach a defined threshold. The same solution could also be modified for any other building such as workplaces and hospitality to minimise the risk of the spread of COVID-19. 

For more information please contact enquiries@iesve.com

References

https://www.irishtimes.com/news/health/ventilation-a-key-to-controlling-covid-spread-expert-says-1.4617424