The Safest Indoor Air Quality - For Your Child!
In order to create the best learning climate, Prem has invested significantly to ensure that the air quality inside the classroom meets the strictest international air quality standards as well as Center of Disease Control (CDC) recommendations for reduced COVID-19 transmission risks.
WHO PM2.5 Targets
Prem’s CleanFlow positive pressure system is designed to meet the strict WHO air quality targets of below 10 μg/m³ PM2.5 -even during the Chiang Mai smoke season. Regularly certified by AirGradient.
Low CO2 - Smart Kids
Low CO2 levels have been shown to significantly improve test scores. Prem’s fresh air system ensures that CO2 levels inside the classrooms remain low and within European Standards.
Reduced COVID-19 Risk
Prem’s air quality monitoring system automatically regulates the amount of fresh air of the CleanFlow system thus meeting CDC regulations to reduce COVID-19 transmission risks.
Dr. Anjana (Bangkok Hospital) on PM2.5 Effects on Children
Does your child have Asthma or other Air Quality related Sensitivities?
If your child has asthma or any other respiratory disease or sensitivity, we care. All our homerooms and many common areas are outfitted with the CleanFlow positive pressure system that keeps indoor air pollution within WHO recommendations.
It is possible to fit ultra high performance medical-grade filters into the machines in order to address specific conditions that your child might have. Please contact us for a site visit to learn more.
Prem’s Air Quality Monitoring & Communication System
Prem’s air quality monitoring and communication system is provided by AirGradient. It consists of more than 60 air quality sensors that cover the whole school (classrooms from EY1 to the IB Diploma classrooms as well as common spaces). It also monitors the air quality at four outside locations.
Measurements are taken approximately every 2 minutes and are sent to a cloud-based platform for real-time analytics. The platform automatically alerts relevant stakeholders if the air quality stays outside strictly defined air quality bands and also provides daily reports to Prem decision-makers as well as parents.
Large displays throughout the campus (e.g. in the Gym) continuously display the air quality so that teachers can make informed decisions and the website widget provides an overview of the current outdoor and indoor air quality.
CO2 and Cognitive Impact
The CleanFlow positive pressure system installed in Prem classrooms and learning spaces not only removes PM2.5 but also decreases CO2 levels substantially. Prem now consistently keeps average CO2 levels below the European standards of around 1000-1500ppm whereas classrooms without fresh air systems often go beyond 3000ppm.
High CO2 levels substantially impair cognitive performance, student well being and test scores. Prem’s IB exam room is also one of the many rooms that has a CleanFlow positive fresh air system installed.
Article about CO2 impact from the Guardian.
Prem’s Air Quality Policies & Certificates
Prem continuously updates its air quality procedures and policies. It gives detailed instructions to teachers and staff and ensures that processes and responsibilities are clearly defined in order to minimize the effect of air pollution.
Prem undergoes regular air quality assessments through AirGradient, a company that provides air quality monitoring services to Prem. The latest reports and certificates can be accessed on their website.
How the CleanFlow System reduces Prem’s COVID-19 transmission risk
To reduce the transmission risk of COVID-19, a high ventilation rate of outside air is crucial in order to flush out airborne particles that could carry the COVID-19 virus. A good indicator of adequate ventilation rates is the indoor CO2 value. Most European and American Centers of Disease Controls (CDCs) recommend CO2 levels below 1000 ppm (outside air has a CO2 of approx. 400 ppm).
In September 2020, Prem equipped all its main classrooms, sports facilities, and common areas with CleanFlow positive pressure systems in order to ensure extremely low PM and CO2 inside the classrooms and high fresh air ventilation, so as to reduce COVID-19 transmission risks.
More than 70 AirGradient air quality sensors continuously measure the CO2 values in all main classrooms and automatically increase the ventilation rates as soon as elevated CO2 values are detected. The system analysis more than 40.000 data points every day and adjusts the ventilation accordingly.
As a result, Prem now achieves CO2 levels well within international CDC recommendations for classrooms. It is currently the only school in Thailand having deployed this sophisticated system.
Prem’s Journey towards Clean Air Success
Prem was one of the first schools in Chiang Mai to deploy powerful air purifiers during Chiang Mai smoke season but inconsistently able to reach its strictest clean air targets at the peak of the worst AQI.
With the newly deployed CleanFlow system, Prem now achieves indoor air quality levels comparable to some of the cleanest cities in the World. According to Prem’s latest Air Quality Certification, its rooms have a lower PM2.5 level than one of the cleanest capital cities in Europe: Helsinki, Finland.
Prem’s indoor air quality is better than some of the Cleanest Cities in the World.

Prem’s Positive Pressure System - (Near) Zero AQI even on the worst polluted days
In 2020 Prem equipped all its main classrooms (homerooms), common areas, fitness and sports hall with powerful CleanFlow positive pressure systems. This system was trialed throughout the previous smoke season and achieved near zero AQI values on the worst polluted days (e.g. consistently kept the PM2.5 levels inside the classroom close to zero when it was nearly 400 US AQI outside).
How does the System work?
The CleanFlow system takes outside air, filters it through a set of high performance filters and pushes it into the classrooms. The slightly increased pressure inside the classrooms prevents dirty air from entering and also flushes out CO2 thus creating a safe and healthy learning environment.
Superiority to Air Purifiers
Air purifiers constantly fight with dirty air entering the classrooms and thus the purification always correlates with the outside air quality. On highly polluted days e.g. during the Chiang Mai smoke season, most air purifiers will not be able to comply with WHO safe air targets. The CleanFlow system will prevent dirty air from entering the room and can thus achieve near zero PM2.5 levels. The chart below shows a real data comparison between air purifiers and positive pressure systems. The gray line shows the outside air pollution. The PPS system is able to bring the inside air PM2.5 levels to zero whereas the air purifier is not able to maintain a healthy level.

Prem’s Sports Hall - Clean Air during Exercise
Prem’s Gym contains the same air volume as around 100 classrooms and thus poses unique challenges to ensuring a safe and healthy air quality. Considering that during exercise you are inhaling a much higher number of particles, it was always a priority for Prem to ensure clean air in its sports hall.
Prem’s gym is the first sports hall in Chiang Mai that has a CleanFlow positive pressure system installed to ensure that students can work out safely even when outside pollution levels are very high.

Prem’s Sports Hall: Workout with your Friends -not with PM2.5.
Prem’s Air Quality System - 3 Key Elements
Prem’s air quality system consists of three crucial elements that as a whole ensure that your child breathes the best possible air and thus achieves the highest levels of wellbeing and productivity. It consists of (1) Being Responsible, (2) Monitoring & Communication and (3) Continuous Improvements.
Be Responsible!
Maintaining healthy air during the Chiang Mai smoke season is hard and unfortunately many schools are not taking the health impacts seriously enough. Prem recognizes the importance of uncompromised clean air and is committed to surpass WHO air quality targets in its main classrooms, common spaces and indoor sports facilities. Prem’s Air Quality Committee is chaired by the Head of School and includes representatives from parents, teachers, operations and students. It meets regularly and makes key decisions not only on the air purification equipment that Prem uses but also on integrating air quality as an important element in the curriculum (e.g. within STEAM to build air quality sensors with the students). Regular information sessions are also carried out for the parent community. Prem is engaged in several clean-air projects e.g. with the National Astronomical Research Institute (NARIT) and actively collaborates in the Chiang Mai International School Network for Clean Air.
Monitoring & Communication
Prem uses a state-of-the-art air quality monitoring and communication system from AirGradient. Over 60 air quality sensors measure the air quality in classrooms, common areas, and outdoor locations and analyze the data in real-time. The system automatically informs teachers and staff if the air reaches unhealthy levels. Daily reports about the air quality in each classroom are available in the parent portal and summary data displayed on the Prem website.
AirGradient also provides a regular independent certification of Prem’s indoor environment with detailed analytics and recommendations to ensure that the high standard that Prem sets for itself is consistently achieved.
Continuous Improvement
Prem has always been at the forefront of air quality management among schools in Thailand. The data-centric approach with sensors in nearly all of its learning spaces lays the base for continuous improvements. Prem is committed to remain a leading school in optimizing its learning environment with a priority on health, safety, wellbeing and productivity.