Current standards for indoor air quality in schools: international approaches
Indoor air quality regulations in educational settings vary widely across the world, with some regions adopting strict regulations and others still developing them. As awareness grows about the link between air quality and health, both mandatory regulations and recommendations have been put in place to protect students and staff. Here, we explore some of the main standards and recommendations in different countries, highlighting approaches, challenges, and opportunities for improvement.
United States: EPA recommendations and ASHRAE standards
In the United States, school air quality is primarily guided by recommendations from the Environmental Protection Agency (EPA) and standards from the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE).
EPA and the tools for schools program: The EPA offers a comprehensive guide for improving IAQ in schools through its “Indoor Air Quality Tools for Schools” program. This guide provides IAQ assessment and maintenance strategies, though federal adoption is not mandatory. Despite this, many schools have implemented these recommendations, particularly in districts aiming to enhance health and academic performance.
ASHRAE standard 62.1: ASHRAE sets a reference standard for ventilation in non-residential buildings, which includes specific recommendations for classrooms regarding air changes and minimum ventilation rates. During the COVID-19 pandemic, ASHRAE updated this with Standard 241, focusing on infection control in indoor spaces, recommending five air changes per hour in occupied spaces. Although not federal law, this standard has been adopted as a reference in many U.S. school districts.
European Union: HealthVent and REHVA guidelines
In Europe, IAQ regulation in schools largely depends on each country, though there are EU-level guidelines that provide a framework for implementing national standards.
HealthVent Project: This European initiative provides IAQ and ventilation guidelines for enclosed environments, including schools, designed to align ventilation values with WHO recommendations. HealthVent emphasizes the need to maintain adequate CO₂ levels and reduce airborne particles in classrooms and other occupied spaces.
REHVA (European federation of heating, ventilation, and air conditioning associations): REHVA provides technical guidelines to improve IAQ in school buildings, particularly in terms of ventilation rates and particle filtration. According to their recommendations, mechanical ventilation systems in schools should be capable of maintaining CO₂ levels below 800 ppm (parts per million) in enclosed spaces.
Standards in Italy and Germany: Italy has developed its own National IAQ Action Plan for schools, requiring ventilation and monitoring measures in densely populated urban schools. Germany has implemented similar policies through state-specific ventilation guidelines, although enforcement varies by federal state.
Japan: A Focus on CO₂ Monitoring
Japan has implemented a continuous CO₂ monitoring approach in classrooms to control IAQ in schools. Since the COVID-19 pandemic, the Japanese government has recommended using CO₂ sensors in educational spaces to keep levels below 1,000 ppm. While not mandatory, this recommendation has led many schools to adopt real-time IAQ monitoring systems.
International Comparison of Standards and common challenges
Comparing the approaches of different countries toward IAQ in schools reveals significant disparities in standards and compliance with recommendations. While some countries have implemented stringent regulations and provided resources to improve IAQ, others rely on non-binding guidelines and the goodwill of educational institutions to implement necessary improvements.
- United States: Non-binding recommendations provide a model where wealthier school districts can more easily apply ASHRAE standards and EPA guidelines, while lower-income areas struggle to implement even basic ventilation and purification measures.
- European Union: European countries have made considerable progress in IAQ regulation for schools, partly due to projects like HealthVent and REHVA, which drive standardization of ventilation rates and air quality. However, the application and monitoring of these guidelines can vary widely, depending on available resources.
- Asia (Japan): Japan has adopted a highly specific CO₂ monitoring strategy, which offers a direct and accessible approach to maintaining safe air quality levels in classrooms. However, this approach limits control over other health-impacting pollutants, such as fine particles and VOCs.
Challenges in implementing IAQ Standards
Globally, one of the greatest challenges in improving school IAQ is the lack of resources to update or install ventilation and purification systems. In countries with limited resources, including developed regions such as rural areas in the U.S. and Europe, schools often lack the infrastructure to meet recommendations from organizations like ASHRAE or WHO.
Moreover, proper maintenance of ventilation systems remains a common issue, as many schools face budgetary and logistical difficulties in keeping filters and systems in optimal condition. A report from Lawrence Berkeley National Laboratory highlighted that many schools, particularly in older buildings, have HVAC systems not designed to support recommended ventilation rates, reducing their effectiveness in maintaining adequate IAQ.
Case studies and current projects for improving school air quality
Various projects worldwide have implemented innovative strategies to improve IAQ in schools. These case studies highlight the effectiveness of different solutions, from advanced IAQ monitoring systems to the use of air purifiers in learning spaces. Below are some key examples, including data and outcomes reflecting the positive impact of these projects on student health and well-being.
GBG_A2CC Project in Barcelona: “Climate Refuge” in Schools
The GBG_A2CC project, known as “Climate Refuge,” was launched in Barcelona as an initiative to improve school environments by implementing infrastructure interventions, transforming schools into “cool islands.” This project aims not only to reduce the impact of heat waves but also to enhance IAQ in classrooms and playgrounds, especially in areas with high traffic levels.
- Methodology: Air quality monitoring sensors were installed in several schools, measuring parameters like CO₂, PM2.5, and PM10 in real-time. Additionally, air purifiers were added in classrooms with high contaminant levels, and ventilation improvements were made in indoor spaces.
- Results: Data collected before and after interventions showed a significant reduction in fine particle levels (PM2.5 and PM10), with a decrease of up to 25% compared to initial measurements. Respiratory symptoms among students also declined, demonstrating the effectiveness of these measures in terms of both IAQ and student health.
Clean Air for Schools Project in Colorado, USA
Led by the Lawrence Berkeley National Laboratory and funded by ESSER and the CDC, the Clean Air for Schools Project in Colorado has implemented portable air purifiers and monitoring systems in classrooms across several Denver schools. The main goal of the project is to assess whether these interventions can reduce contaminant levels, reduce respiratory illnesses, and improve school attendance.
- Interventions: HEPA purifiers were installed in selected classrooms, along with IoT sensors continuously measuring CO₂, PM2.5, VOCs, and other air quality parameters. These devices send alerts to administrators when contaminant levels exceed recommended limits, enabling immediate action.
- Impact: Initial results suggest a 50% reduction in respiratory infection risk in classrooms with active air purifiers compared to classrooms without these interventions. Additionally, CO₂ and PM2.5 levels remained below ASHRAE-recommended thresholds, even during peak occupancy hours.
IAQ Monitoring in Boston: Real-Time data and public transparency
In Boston, an innovative approach has been the installation of over 4,400 air quality sensors in 125 schools, funded by the Elementary and Secondary School Emergency Relief (ESSER) program. These sensors, distributed across classrooms, main offices, and common areas, measure variables such as temperature, humidity, CO₂, and fine particles, enabling administrators to make informed decisions about ventilation and purification.
- Data Transparency: One of the project’s highlights is data transparency. IAQ measurements from each classroom are publicly available through an online dashboard, allowing parents, students, and administrators to check air quality in real time.
- Findings: Significant variations in air quality were discovered between different classrooms within the same building, helping to identify areas with specific ventilation problems. Overall, data suggests that classrooms with constant monitoring and ventilation adjustments achieve significantly safer IAQ levels compared to those without active monitoring.
Key takeaways
These projects provide valuable lessons for other regions interested in improving IAQ in schools. First, the importance of real-time monitoring systems is undeniable, as they allow quick responses and adjustments to changes in air quality. Second, data transparency helps create a sense of shared responsibility and enhances trust among parents and the community. Finally, advanced technology, such as IoT sensors and portable purifiers, has proven effective in school environments where traditional ventilation systems may be inadequate or outdated.
Ensuring optimal indoor air quality (IAQ) in schools is a vital investment in the health and future of our children. By following best practices, embracing international standards, and implementing cutting-edge technologies like AQSENSOR and Dust Free from AirQuality Safe, schools can create safe and supportive learning environments that prioritize well-being. Clean air fosters concentration, reduces absenteeism, and promotes long-term health, providing a foundation for academic success. With tools from AirQuality Safe, educators and administrators have the resources they need to monitor and improve IAQ, creating classrooms where students can thrive. Together, we can build a healthier future for everyone.
References:
- Environmental Protection Agency (EPA). “Indoor Air Quality Tools for Schools: Actions to Improve Indoor Air Quality.” Publication # 402-F-99-008. September 1999. Available at: EPA
- ASHRAE. “ASHRAE Standard 62.1 for Ventilation in Non-Residential Buildings” and “ASHRAE 241 for Indoor Infection Control.” ASHRAE, 2021. More information at: ASHRAE Standards
- HealthVent Project. “Health-based ventilation guidelines for Europe.” European Union. More information at: HealthVent
- Center for Green Schools (USGBC). “Managing Air Quality in the Pandemic: How K-12 Schools Addressed Air Quality in the Second Year of COVID-19.” US Green Building Council, 2022.
- Lawrence Berkeley National Laboratory. “Impact of Indoor Air Quality on Health and School Performance.” Study in U.S. schools, 2021. Available at: LBNL
- Vermont ARP School Indoor Air Quality Grant Program. “Grant Guide for HVAC System Improvement in Schools.” American Rescue Plan Act, 2021.
- EFA (European Federation of Allergy and Airways Diseases Patients’ Associations). “Report on the Impact of IAQ on School Asthma.” Brussels, 2020.
- GBG_A2CC Project (Climate Refuge). “Air Quality Assessment in Barcelona Schools.” ISGlobal, Barcelona, 2021. Available at: ISGlobal
- Attune IoT Monitoring System. “Use of IoT Sensors for Air Quality Monitoring in Schools.” 2024.
- American Rescue Plan (ARP). “Standards and Funding for Improving Air Quality in Schools.” American Rescue Plan Act, 2021.
- World Health Organization (WHO). “Guidelines on Indoor and Outdoor Air Quality.” WHO, 2020. See: WHO
- Boston School IAQ Project. “IAQ Study in Boston Schools with IoT Sensors.” Boston University School of Public Health, 2023.
- Centers for Disease Control and Prevention (CDC). “Recommendations for Post-COVID School Ventilation and Air Quality.” CDC, 2023.
- REHVA. “Technical Guide for Ventilation in Educational Buildings in Europe.” REHVA, 2020.
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