In the last decade, modernization of school buildings in Ukraine is being carried out. Thermorenoval measures such as thermal insulation of exterior walls and replacement of existing windows are most often used. Installing hermetic metal-plastic windows significantly reduces the heat loss of premises, but leads to disturbance of air regime, as outdoor air infiltration is often the only source of external fresh air supply. The study of the air environment in the classrooms is very relevant, since about 20% of the total population spends a significant part of their day in preschool and school settings. Failure to comply of microclimate parameters in classrooms, in particular due to the increase of CO2 concentration, leads to deterioration of the state of health and workability of students, as well as insufficient mastering of the educational material. Due to the deterioration of the environmental state of the environment, the concentration of CO2 in the outside air of large cities often exceeds the permissible values. This leads to an increase in the productivity of ventilation systems, designed to assimilate CO2. The article presents the results of analytical studies of changes in CO2 concentration in classrooms during the entire period of their stay in the students under the three schemes of organization of air exchange, namely when closed windows during the entire training period and without ventilation; when ventilated class during each breaks and in the presence of inflow and exhaust ventilation in the classrooms. The analysis of the air environment was carried out for the most unfavorable conditions at negative external air temperatures. As a result of the research, it was established that only in the presence of mechanical inflow and exhaust ventilation with an air exchange rate of 30 m3/hour per person provides adequate sanitary and hygienic conditions in the classrooms.
1. Derzhavna sluzhba statystyky Ukrainy. (2018) Zahalnoosvitni ta profesiino-tekhnichni navchalni zaklady. Statystychnyi zbirnyk. [State Statistics Service of Ukraine. General education and vocational schools. Statistical Collection.], Kiev, 134 p. [In Ukrainian].
2. Kapalo P., Vilcekova S., Vozniak O. (2014) Using Experimental Measurements of the Concentrations of Carbon Dioxide for Determining the Intensity of Ventilation in the Rooms. Chemical Engineering Transactions, Vol. 39, pp. 1789–1794.
3. GOST 12.1.007-76* SSBT. (1977) Vrednyie veschestva. Klassifikatsiya i obschie trebovaniya bezopasnosti. [GOST 12.1.007-76 * SSBT. Harmful substances. Classification and general safety requirements], Мoskva, 10 p. [In Russian].
4. Steiger S., Noske F., Kersken M., Hellwig R. T. (2008) Untersuchungen zur Beluftung von Schulen // [Investigations on the ventilation of schools] Tagungsband Deutsche Kalte-Klima-Tagung 2008, Vol. 19, Is. 21, Beitrag IV, 13 p. [In Deutsch].
5. Hellwig R. T., Antretter F., Holm A., Sedlbauer K. (2009) Untersuchungen zum Raumklima und zur Fensterluftung in Schulen [Examinations of the indoor climate and window ventilation in schools]. Bauphysik, Vol. 31, Is. 2, pp. 3-12.
6. DSanPiN 5.5.2.008-01 (2001) Vlashtuvannia, utrymannia zahalnoosvitnikh navchalnykh zakladiv ta orhanizatsii navchalno-vykhovnoho protsesu. [SSanR&R 5.5.2.008-01. Arrangement, maintenance of general educational institutions and organization of educational process], Kiev, 49 p. [In Ukrainian].
7. BS EN 13779:2007. (2008) Ventilation for non-residential buildings. Performance requirements for ventilation and room-conditioning systems. 76 р.
8. Ryimarov A. G., Savichev V. V. (2014) K opredeleniyu trebuemogo vozduhoobmena v pomescheniyah obschestvennyih zdaniy v zavisimosti ot kachestva naruzhnogo vozduha. [To determine the required air exchange in the premises of public buildings, depending on the quality of outdoor air], Internet-vestnik VolgGASU. Ser.: Politematicheskaya, Vol. 2 (33), 4 p. [In Russian].
9. Skolko veshat v grammah: normyi CO2. (2016) [How much to hang in grams: CO2 standards], https://tion. ru/BLOG/NORMY-CO2/.
10. Elterman V. M. (1980) Ventilyatsiya himicheskih proizvodstv. [Ventilation of chemical plants], Мoskva, 288 p. [In Russian].
11. Zhukovskyi S. S., Vozniak O. T., Dovbush O. M., Liulchak Z. S. (2007) Ventyliuvannia prymishchen. [Ventilation of the premises], Lviv: Publishing House of the Lviv Polytechnic National University, 476 p. [In Ukrainian].
12. DBN V.2.2-3-97. (1997) Budynky ta sporudy navchalnykh zakladiv. [Buildings and facilities of educational institutions], Кiev, 50 p. [In Ukrainian].