In over 65% of schools and kindergartens, there are no established ventilation systems, according to a national study by the Bulgarian Association "Heating, Ventilation and Air Conditioning" (BAOVK). The study was conducted at the end of 2025 in the form of a voluntary online survey, with the assistance of the Regional Education Directorates, and covers over 200 schools and kindergartens from six regions in the country.
The data from the study show that just over 1% of educational institutions have central mechanical ventilation. In about one-fifth of the buildings, partial solutions have been implemented, usually in individual rooms, while only just over 4% of respondents indicate that they plan to build such systems.
The results also show that in a significant part of the educational institutions, there is a lack of systematic control over the indicators of indoor air, such as temperature, relative humidity, and carbon dioxide concentration. Over half of the participants in the study indicate that they measure these parameters only periodically, while in over 30% of the educational institutions, there is no available data on the current air quality in the rooms.
Regarding the regulatory framework, nearly half of the respondents state that they are only partially familiar with the requirements for minimum amounts of fresh air in classrooms. The study also shows limited awareness of the link between ventilation and the health of students and teachers.
Over 45% of respondents share that they have heard of the existence of European and national programs for energy-efficient measures, including ventilation systems, but do not have specific information on the conditions and procedures. A relatively small share of the participants - just over 4% - define the need to improve air quality as urgent.
"The results clearly show that the problem with ventilation in educational buildings is not isolated, but systemic. In a large part of the schools, there is a lack of both technical solutions and sufficient information," comments Ivan Armyanov, a member of the Board of Directors of BAOVK.
BAOVK will continue its active work on the topic of air quality in educational institutions, providing expert support and consultations.