Analiza vplivov tesnosti stavbnega ovoja in naravnega prezračevanja na koncentracijo delcev v notranjem zraku stavb : magistrsko delo št.: 58/II.ST

Božič, Tajda (avtor), Dovjak, Mateja (mentor), Vaupotič, Janja (komentor)

V raziskavi obravnavamo vpliv tesnosti stavbnega ovoja na koncentracijo delcev velikosti od 10 do 1000 nm, ki se v stavbo nekontrolirano infiltrirajo iz zunanjega zraka. Na osnovi gradbeno-tehničnih karakteristik smo izbrali dve stavbi, od katerih ima stavba 1 nižjo zrakotesnost ovoja (S1-NT), stavba 2 pa višjo zrakotesnost ovoja (S2-VT). V vsaki stavbi smo v izbranem testnem prostoru kontinuirno merili številčne koncentracije delcev po en teden v neogrevalni in ogrevalni sezoni. V zunanjem zraku je glavni vir delcev v neogrevalni sezoni promet, v ogrevalni sezoni pa promet in kurišča. Ker sta nas v prostoru zanimali predvsem koncentracija različno velikih delcev zunanjega izvora in hitrost njihove infiltracije, smo notranje izvore delcev zmanjšali na minimum (v prostor je vstopala ena oseba le v času odpiranja in zapiranja okna). Pri vseh enotedenskih meritvah v prostoru smo uporabili enoten način odpiranja in zapiranja okna. Pri vrednotenju podatkov smo se osredotočili na obdobja, ko je bilo okno zaprto, in za ta obdobja izračunali številčne koncentracije delcev (CN je število delcev v cm–3) štirih frakcij (premer v nm: <100, 100–200, 201–500, >500). Dodatno smo v prostoru spremljali še koncentracijo radona (CRn) in ogljikovega dioksida (CCO2), ki sta kazalnika učinkovitosti prezračevanja, ter temperaturo (Tin). V neposredni bližini testnega prostora smo v zunanjem zraku sočasno spremljali temperaturo (Tout), tlak (p), hitrost vetra (v), padavine (P) in CRn. Po metodi s sledilnim plinom CO2 smo izračunali zrakotesnost obeh testnih prostorov. Potrdili smo, da ima stavba 1 manj zrakotesen stavbni ovoj (Ninf = 0,40 h–1) kot stavba 2 (Ninf = 0,23 h–1). V obdobjih, ko je bilo okno zaprto, so povprečne številčne koncentracije delcev naslednje: (i) v S1-NT v neogrevalni sezoni CN <100 = 1276 cm–3, CN 101–200 = 957 cm–3, CN 201–500 = 408 cm–3, CN >500 = 6 cm–3 in v ogrevalni sezoni CN <100 = 2622 cm–3, CN 101–200 = 1119 cm–3, CN 201–500 = 309 cm–3, CN >500 = 11 cm–3; (ii) v S2-VT v neogrevalni sezoni CN <100 = 2060 cm–3, CN 101–200 = 901 cm–3, CN 201–500 = 311 cm–3, CN >500 = 5 cm–3 in v ogrevalni sezoni CN <100 = 4054 cm–3, CN 101–200 = 2558 cm–3, CN 201–500 = 643 cm–3, CN >500 = 13 cm–3. V stavbi 1 so koncentracije delcev v ogrevalni sezoni višje kot v neogrevalni sezoni le pri določenih frakcijah, medtem ko so v stavbi 2 v ogrevalni sezoni znatno višje kot v neogrevalni v vseh frakcijah. Iz navedenih rezultatov razberemo tudi, da so v ogrevalni sezoni koncentracije delcev višje v stavbi 2 kot v stavbi 1, kar kaže na dobro infiltracijo delcev tudi skozi bolj zrakotesen ovoj, ki ga ima stavba 2. Izračunali smo hitrost infiltracije in ugotovili, da koncentracija delcev <100 nm najhitreje naraste iz minimalne na maksimalno vrednost (S1-NT: ?t = 3,8–5,4 h; S2-VT: ?t = 7,3–3,4 h), kar nakazuje na to, da med vsemi frakcijami najhitreje prehajajo skozi ovoj stavbe. Če smo delcem izpostavljeni daljše obdobje, negativno vplivajo na naše zdravje. Glede na to, da ljudje večino svojega časa preživimo v zaprtih prostorih, je poznavanje koncentracij delcev v zunanjem zraku in razumevanje njihovega prehoda iz zunanjega zraka v notranje okolje skozi ovoj stavbe ključnega pomena pri načrtovanju ukrepov za izboljšanje stanja.

• Jezik: Slovenski jezik
• Ključne besede: gradbeništvo, magistrska dela, delci, Rn, CO2, stavbni ovoj, zrakotesnost, infiltracija
• Vrsta gradiva: Magistrsko delo/naloga
• Tipologija: 2.09 - Magistrsko delo
• Organizacija: FGG - Fakulteta za gradbeništvo in geodezijo
• Kraj izida: Ljubljana
• Založnik: [T. Božič]
• Leto izida: 2023
• Št. strani: XII, 84 str.
• PID: 20.500.12556/RUL-146826-68328eb8-7023-595d-82f9-b05cb71505c6
• UDK: 697.9:699.872(043.3)
• COBISS.SI-ID: 155717635
• Datum objave v RUL: 14.06.2023

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Analysis of the effects of airtightness and natural ventilation on the concentration of particles in the indoor air : master thesis no.: 58/II. ST

Izvleček

This study analyses the effect of the airtightness of the building envelope on the concentration of aerosol particles between 10 and 1000 nm that uncontrollably infiltrate the building from the ambient air. Two buildings were selected on the basis of their physical characteristics, with Building 1 having lower airtightness (S1-NT) and Building 2 having higher airtightness of the building envelope (S2-VT). In each building, particle number concentrations were measured continuously for one week in the selected test room during the non-heating and heating season. In ambient air, traffic is the primary source of particles in the non-heating season, and traffic and combustion are the primary sources in the heating season. As we were mainly interested in the concentration of differently sized particles of outdoor origin in the room and their infiltration rate, we minimised the indoor sources of particles (one person entered the room only when opening and closing the window). For all one-week measurements in the room, we used the same method of opening and closing the window. For the evaluation of the data, we focused on the periods when the window was closed and calculated particle number concentrations (CN is the number of particles in cm–3) of the four fractions (diameter in nm: <100, 100‒200, 201‒500, >500) for these periods. In addition, radon (CRn) and carbon dioxide (CCO2) concentrations, which are indicators of ventilation efficiency, and temperature (Tin) were monitored in the room. In the immediate vicinity of the test room, temperature (Tout), pressure (p), wind speed (v), precipitation (P) and CRn were monitored simultaneously in the ambient air. The airtightness of the two test rooms was calculated using the CO2 tracer gas method. We confirmed that Building 1 has a less airtight building envelope (Ninf = 0.40 h–1) than Building 2 (Ninf = 0.23 h–1). During periods when the window was closed, the average particle number concentrations are as follows: (i) in S1-NT in the non-heating season CN <100 = 1276 cm–3, CN 101–200 = 957 cm–3, CN 201–500 = 408 cm–3, CN >500 = 6 cm–3 and in the heating season CN <100 = 2622 cm–3, CN 101–200 = 1119 cm–3, CN 201–500 = 309 cm–3, CN >500 = 11 cm–3; (ii) in S2-VT in the non-heating season CN <100 = 2060 cm–3, CN 101–200 = 901 cm–3, CN 201–500 = 311 cm–3, CN >500 = 5 cm–3 and in the heating season CN <100 = 4054 cm–3, CN 101–200 = 2558 cm–3, CN 201–500 = 643 cm–3, CN >500 = 13 cm–3. In Building 1, the particle number concentrations in the heating season are higher than in the non-heating season only for specific fractions, while in Building 2 they are significantly higher in the heating season than in the non-heating season for all fractions. The above results also show us that in the heating season, the particle concentrations are higher in Building 2 than in Building 1, indicating that the particles are well infiltrated also through the more airtight envelope of Building 2. We calculated the infiltration rate and found that the concentration of particles <100 nm increases most rapidly from the minimum to the maximum value (S1-NT: 䀆t = 3.8–5.4 h; S2-VT: 䀆t = 7.3–3.4 h), indicating that they pass through the building envelope the fastest among all fractions. If exposed to particles for a prolonged period of time, they have a negative impact on our health. Given that people spend most of their time indoors, knowing the concentrations of particles in ambient air and understanding how they move from ambient air to the indoor environment through the building envelope is crucial for planning improvement measures.

• Ključne besede: civil engineering, particles, Rn, CO2, building envelope, airtightness, infiltration