Ambitious Royal Lyceum Antwerp is working on a smart ventilation plan and more green

Measuring with NO2 measuring tubes

In December 2019, the first year students hung up test tubes at various places in and around the school to map the concentrations of nitrogen _dioxide (NO2). Nitrogen dioxide is released during high-temperature combustion processes, especially in traffic and industry. The tubes were hung in classrooms along the playground and the quieter Hertoginstraat as well as in classrooms along the busy Mechelsesteenweg. Both indoor and outdoor air were measured for five weeks in order to be able to compare the two. The measurements were repeated in January 2021.

Cautious Conclusions

The results of the first measurement campaign in 2019 indicated a clear direction. For example, it turned out that the concentration of nitrogen dioxide in the classrooms was on average half lower than in the open air, and that difference was greater than expected. This may be explained by the fact that the windows were almost always closed during the measurement period. After all, the classrooms were hardly used because of exams and the Christmas holidays. This made it difficult for the exhaust fumes from the traffic to penetrate. The concentrations along Mechelsesteenweg and Hertoginstraat also did not differ from each other. This may indicate a strong street canyon effect, making it more difficult for air pollution in the narrow Hertoginstraat to escape than in the wider Mechelsesteenweg. The concentrations of nitrogen dioxide on the playground were about 3.5 µg/m³ lower than on the street side.

Follow-up measurements

Irene Bergwerf, chemistry teacher: “ We were quite surprised about a number of measurement results. That is why we conducted a follow-up campaign with measuring tubes in January 2021. We wanted to investigate whether the difference in nitrogen dioxide concentrations between outside and inside remained the same when the rooms were used and ventilated. And guess what: there was still a clear difference between the concentrations inside and outside, but that difference was much less than in 2019. We did see again that the values along the Hertoginstraat were just as high as along the Mechelsesteenweg. Finally, we did an experiment in which we closed our school gate with plastic sheeting to better shield the playground from traffic, but this had no measurable effect on the difference in air quality between the playground and the street. ”

Healthy ventilation and airing

In addition to nitrogen dioxide, the KLA students also measured the concentrations of particulate matter and carbon dioxide. They did this with the help of sensor boxes. Based on the insights from all those measurements, the school wanted to come up with a smart ventilation plan. During a first measurement campaign, all windows and doors remained closed to investigate what happens if you do not air or ventilate. Irene Bergwerf: “ This experiment showed that the CO ₂ concentrations easily exceeded 2000 parts per million (ppm), with peaks of up to 3000 ppm. Far too high when you know that the guideline value for a pleasant classroom climate is only 900 ppm. Only in the chemistry room were the peaks limited to 1100 ppm, presumably thanks to the extractor hood. So keeping out traffic pollution by closing all windows and doors is clearly not a good idea .”
In November and December 2020, the Royal Lyceum started working with sensor boxes again. That was very welcome during Corona. This time, the boxes were used to monitor whether the classes were adequately ventilated: is it possible to achieve the target value of 900 ppm in the classrooms? Fortunately, the measurements showed that the guideline value was almost always respected in the different classes.

A greener school

The KLA is located in a densely built-up area with little greenery. However, a green environment has many advantages; also for air quality. That is why the KLA is doing its part by providing more greenery at school in various ways.
Inspired by the Pure Air project, the students of the fifth year of the STEM and Economics specializations started their own mini-company 'Greenwall' in the 2019-2020 school year. They designed a plant wall for the classroom themselves. The students took part with their idea in the VLAJO (Flemish Young Enterprises) competition for mini-enterprises. And with success because Greenwall won the Antwerp final of the VLAJO mini-enterprise of the year .

Director Ann Huybrechts: “ We know that the effect of those green walls on the purification of indoor air is negligible, although there are indications that a plant wall in the classroom can reduce CO ₂ concentrations a bit. And of course green has a positive effect on the comfort and well-being of the students. But above all, the 'Greenwall' project was an ideal starting point for learning and working with our students about air quality .”

This gave the students a taste. As a follow-up to the Greenwall project, the third grade STEM students designed and built a green outdoor classroom on the playground, and 18 students volunteered to green the school cafeteria.
Unfortunately, not all ambitions turned out to be easy to achieve. The school has long dreamed of a green facade on the Mechelsesteenweg. Ann Huybrechts: “ We had a plan drawn up by Landscape Agency Avant-Garde, whereby the balconies would be transformed into beautiful green walls. Unfortunately, a stability study showed that there are not sufficient guarantees that the balconies will be able to support the planters .”

School Street

One of the challenges of the Hertoginstraat and its surroundings is the parking pressure. That is why the KLA, in collaboration with the city, offers a number of parking spaces in its parking garage as neighborhood parking for local residents. For example, there is less circulating traffic and the available parking spaces can be used more efficiently.
And it didn't stop there. The school applied for the status of 'school street' a few years ago. As a result, Hertoginstraat will be temporarily closed at the beginning and end of the school day. “ A good decision ,” says director Ann Huybrechts, “ because this intervention is better for air quality and also ensures a safer school environment for our students .”