Over the past few weeks, ISB has been monitoring the air quality on campus through our outdoor pollutant sensor, as well as testing the indoor air quality in a number of learning spaces.
Outdoor Monitor
There were questions raised about why we were seeing variations in readings between different monitors. To ensure that our readings are valid and reliable, we worked with Stefan Berder from GAMS and Charlie Thomson from Environment Assured to account for these differences.
Firstly we would like to mention that the data on our website comparing ISB with Sukhumvit is based on the readings from similar model monitors which allows us to make reliable comparisons. Since we started collecting this data, we see that the PM2.5 in Nichada Thani is consistently lower than in downtown Bangkok.
With regards to the differences in readings between our outdoor monitor and other common monitors there is an expected difference in measurements due to the technology used and expected reliability of the units. The outdoor air monitor located on our campus is a quality device and is expected to be reliable. This device has been benchmarked with five other monitoring devices and while the data is comparable, we have found that high humidity levels could have an impact on our readings. Going into the warm season, we want to be absolutely sure that we have the best equipment on the market and with guidance from GAMS, have therefore decided to purchase a Thermo Fisher 1500 ADR sensor. Similarly to our existing monitor, it is self contained and designed to be outdoors and exposed to the elements. However, it is designed to be more robust in Thailand’s extreme weather conditions.
Elevation of the Outdoor Monitor
In regard to the placement of the monitors on our campus, there was only a minimal difference between PM2.5 readings when placed in lower, key traffic areas and in the elevated location. The elevated location, however, will reduce the possibility of unrelated contamination impacting the reading and the device. It is also protected from interference with network and power connections. The experts reaffirmed that the current location is the most suitable placement for our purpose of making activity-related decisions
Indoor Air Quality Testing
We currently have 8 individual air quality sensors distributed in many indoor areas in the school. Each unit is capturing PM2.5, PM10, CO2, TVOC, temperature and humidity levels 24/7. The data is being compared to data collected by our outdoor monitor in order to determine reduction rates (how much lower it is inside in comparison to what it is outside) and to identify any unexpected changes that occur in our learning spaces over the course of a day.
Thus far, we have been able to see that PM 2.5 levels in classrooms are, on average, 40% lower than outdoors. Please keep in mind that this varies by learning space and we have only been testing for two weeks. The testing thus far has shown that PM2.5 levels vary between 3.2 and 16, few of these being over 10. Of course, PM2.5 levels outdoors have been lower than they were in previous months but our testing at this time is helping us to assess the next action to take in ensuring PM2.5 levels remain continually low in our learning spaces throughout the year.
Indoor Air Purification Testing
As we are measuring air quality in our classrooms, we are also testing different types of in-room air purifiers. As expected, these units are showing detectable, yet minimal reductions. Major factors that are affecting these results are the large sizes of our classrooms, most of which are an average of 60-65 square meters, and students moving in and out of the classrooms multiple times during the day. Therefore in order for us to make significant improvements to the indoor air quality, we are going to evaluate alternative methods such as positive pressure systems. These systems filter outside air and blow it directly into the indoor space. Besides offering lower particle counts because of filtration, they are also meant to lower CO2 and provide a generally better air quality. The positive pressure ensures that the risk of unfiltered outside air entering the room is limited which will keep the air quality stable. We will be working with Environment Assured to test these systems in the next few weeks.
Spaces Ready to Go
ISB already has a number of spaces with positive pressure systems. These include:
Rajendra Gym
Elementary Indoor Gym
ES Hub and the Middle School/High School Library
Cultural Center
MPB 1, 2 and 3
We are currently working with the system providers to modify the air handling units so that we can improve their filtration capacity.
ISB Air Quality Seminar
On February 13th, ISB hosted an Air Quality Seminar, inviting varied speakers and experts to share information on the current situation in Greater Bangkok. Thank you to those that attended and sent questions during and prior to the event. The questions and answers are being added to our FAQ section on the website. Should you have missed the event, you can watch the video recordings, which will be live on our website on by Monday here.
We want to thank our community for your continued input, shared resources and expertise that have allowed us to address this key concern and plan for even greater improvements in the future that will benefit our students and community.