EU Air Quality Directive

The European Union has recently adopted updated air quality standards that introduce stricter limits for major pollutants and place a stronger emphasis on protecting public health. These measures, aligned with the recommendations of the World Health Organization, highlight the importance of ensuring healthy indoor environments, particularly in educational centers. In this context, natural ventilation in schools emerges as a key strategy for improving indoor air quality, contributing to students’ well-being, enhancing concentration, and supporting more effective learning.

OMS Guidelines

The World Health Organization (WHO) provides a global tool that compiles and compares national air quality standards for key pollutants such as fine particulate matter (PM₂.₅), nitrogen dioxide, and ozone. This resource is designed to guide and support countries in moving toward the recommended levels that protect public health. The database reflects a shared international commitment to reducing exposure to air pollution and underscores the importance of implementing effective measures across all environments, including indoor spaces in schools.

Air Quality Documentation (Ministry for the Ecological Transition and the Demographic Challenge)

The Ministry for the Ecological Transition and the Demographic Challenge (MITECO) provides public access to a comprehensive collection of studies, reports, and official data on air quality in Spain. These resources include annual assessments, trend analyses, guidelines, and technical-scientific reports designed to support informed decision-making and compliance with environmental regulations. Together, this documentation offers a robust technical foundation for understanding the status of atmospheric pollutants, their impacts on human health and the environment, and the strategies available to improve air quality. In the context of educational facilities, these resources also highlight the importance of effectively managing indoor air quality. For educational facilities, these resources help underline the importance of effectively managing indoor air quality. Natural solutions such as cross-ventilation and thoughtful opening design can play a significant role in reducing pollutant concentrations and creating healthier environments that support learning.

Technical Building Code (CTE HS-3)

In Spain, the Technical Building Code (CTE) includes Basic Requirement HS-3 on Indoor Air Quality. This requirement establishes that buildings must incorporate ventilation systems that ensure adequate renewal of indoor air in order to remove pollutants generated during occupancy and provide a healthy and comfortable environment for users. The regulation also defines ventilation parameters and design criteria that serve as a framework to ensure that indoor spaces maintain air quality levels that minimize risks to health and well-being.

RITE

The Regulation on Thermal Installations in Buildings (RITE) is the Spanish regulation governing heating, cooling, and ventilation systems to ensure comfort, hygiene, and energy efficiency in buildings, including educational centers. To maintain comfortable indoor temperatures, RITE provides recommended ranges: around 21 °C in winter and approximately 23–25 °C in summer, adjusted according to the activity and occupancy of each space. Additionally, to ensure proper air quality, RITE classifies indoor spaces by quality categories and specifies minimum outdoor air flow rates. For classrooms, it recommends a rate of about 12.5 L/s per person (roughly 45 m³/h per occupant), which corresponds to good indoor air quality. These parameters are crucial for keeping school environments well-ventilated, reducing CO₂ and other pollutant concentrations, and supporting thermal comfort for both students and staff.