Analiza kakovosti notranjega okolja v osnovnošolskih učilnicah z naravnim in hibridnim prezračevanjem : magistrsko delo

Višček, Vita (author), Dovjak, Mateja (mentor), Vaupotič, Janja (comentor)

Namen magistrskega dela je bil izvesti integrirano analizo kakovosti notranjega zraka (IAQ) in toplotnega udobja (TC) v dveh osnovnošolskih učilnicah: eni z naravnim prezračevanjem (U‑NP) in drugi s hibridnim prezračevanjem (U‑HP). Raziskava je temeljila na kontinuiranih meritvah koncentracije CO₂, temperature zraka, temperatur notranjih površin in relativne vlažnosti zraka in je bila izvedena v obdobju od 30. 5. 2025 do 31. 1. 2026. Dopolnjena je bila z meritvami koncentracij radona, delcev PM₂,₅ ter izračunom kazalnikov pričakovana srednja vrednost toplotnega občutka (PMV) in pričakovani odstotek nezadovoljnih oseb v toplotnem okolju (PPD). Rezultati so bili analizirani ločeno za neogrevalno in ogrevalno sezono. V učilnici U‑NP so bile koncentracije CO₂ izrazito odvisne od zasedenosti prostora in prezračevalnih navad uporabnikov. V dveh delih neogrevalne sezone so povprečne vrednosti v času pouka dosegle 815 ± 266 ppm (maj–junij) in 1235 ± 1073 ppm (september–oktober), maksimalne pa presegle tudi 5000 ppm. V ogrevalni sezoni so povprečne vrednosti med poukom dosegle 1044 ± 499 ppm, pri čemer je bila mejna vrednost kategorije III po SIST EN 16798-1:2019 pogosto presežena. Časovni poteki kažejo, da je koncentracija CO₂ po začetku pouka hitro naraščala in praviloma dosegla najvišjo vrednost proti koncu pouka. V učilnici U‑HP je bila koncentracija CO₂ v neogrevalni sezoni nižja in stabilnejša (774 ± 143 ppm, 685 ± 119 ppm), v ogrevalni sezoni pa se je povečala (936 ± 411 ppm) z občasnimi preseganji višjih kategorij kakovosti zraka po SIST EN 16798-1:2019. Toplotno udobje je bilo v učilnici U-HP 70 % časa v najvišji, I. kategoriji, medtem ko je učilnica U-NP to raven dosegala le 40 % časa, preostalih 60 % časa pa je bila uvrščena v nižje kategorije. Koncentracija radona je bila med poukom večinoma nizka (U-NP: do 180 Bq/m³, U-HP: do 343 Bq/m³), pri čemer vrednosti v U-HP lahko presegajo referenčno mejo. Najvišje koncentracije so se pojavljale pred začetkom prezračevanja ter v obdobjih brez prisotnosti (vikendi, počitnice), zlasti v učilnici U-HP. Rezultati potrjujejo, da hibridno prezračevanje omogoča stabilnejše notranje razmere, vendar le ob ustreznem načrtovanju in obratovanju prezračevalnega sistema, medtem ko je naravno prezračevanje močno odvisno od prezračevalnih navad uporabnikov in zunanjih razmer. Ugotovitve predstavljajo podlago za optimizacijo časovnega poteka in intenzivnosti prezračevanja z namenom hkratnega zagotavljanja ustrezne IAQ in toplotnega udobja.

• Language: Slovenian
• Keywords: magistrska dela, gradbeništvo, kakovost notranjega okolja (IEQ), kakovost notranjega zraka (IAQ), prezračevanje, ogljikov dioksid (CO₂), radon (Rn), toplotno udobje, osnovnošolske učilnice
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Place of publishing: Ljubljana
• Publisher: [V. Višček]
• Year: 2026
• Number of pages: 1 spletni vir (1 datoteka PDF (XIII, 80 str.))
• PID: 20.500.12556/RUL-184121
• UDC: 697.9:727(043.2
• COBISS.SI-ID: 283191043
• Publication date in RUL: 30.06.2026

Secondary language

• Language: English
• Title: Analysis of indoor environmental quality in primary school classrooms with natural and hybrid ventilation

Abstract

The aim of this master’s thesis was to perform an integrated analysis of Indoor Air Quality (IAQ) and Thermal Comfort (TC) in two primary school classrooms: one with natural ventilation (U-NP) and the second with hybrid ventilation (U-HP). The study is based on continuous measurements of CO₂ concentration, air temperature, surface temperatures, and relative humidity in the period from May 30, 2025, to January 31, 2026. It was complemented by measurements of radon and PM2,5 concentrations, as well as calculations of Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) indices. The results were analysed separately for the non-heating and heating seasons. In the U-NP classroom, CO₂ concentrations were strongly dependent on occupancy and users’ ventilation habits. During two periods of the non-heating season, average values during class time reached 815 ± 266 ppm (May–June) and 1235 ± 1073 ppm (September–October), with peak values exceeding 5000 ppm. During the heating season, average values reached 1044 ± 499 ppm, with frequent exceedances of the Category III limit according to SIST EN 16798-1:2019. Time profiles show a rapid increase in CO₂ concentration after the beginning of classes, typically peaking towards the end of lessons. In the U-HP classroom, CO₂ concentration was lower and more stable during the non-heating season (774 ± 143 ppm, 685 ± 119 ppm), while in the heating season it increased (936 ± 411 ppm), with occasional exceedances of higher IAQ categories. Thermal comfort in U-HP was 70 % of the time in Category I, whereas U-NP achieved this level only 40 % of the time and fell into lower categories for the remaining 60 %. Radon concentration during class time was generally low (U-NP: up to 180 Bq/m³; U-HP: up to 343 Bq/m³), although values in U-HP may exceed the reference level. The highest concentration occurred before the start of ventilation and during unoccupied periods (weekends, holidays), particularly in U-HP. The results confirm that hybrid ventilation enables more stable indoor conditions when the ventilation system is properly designed and operated, while natural ventilation is highly dependent on user behaviour and external conditions. The findings provide a basis for optimising ventilation strategies in terms of timing and airflow rates to ensure adequate IAQ and thermal comfort simultaneously.

• Keywords: master thesis, civil engineering, indoor environmental quality (IEQ), indoor air quality (IAQ), ventilation, carbon dioxide (CO₂), thermal comfort, primary school classrooms