Filtration effectiveness of outside air in ventilation and air-conditioning systems

Teoretično je opisan pojav zračnega onesnaževanja s prašnimi delci ali aeorosoli in kemična sestava ter vzroki za nastanek le-teh. Opisane so posledice in vplivi na človekovo zdravje, tehnični sistemi ter ukrepi, ki regulirajo ta pojav. V eksperimentalnem delu so bile izvedene meritve številčnih koncentracij prašnih delcev za civilno iniciativo v Sneberjah. Te so bile kasneje s pomočjo matematičnih izrazov ter strokovnih priporočil pretvorjene v masne koncentracije. Uporabljena je bila merilna naprava, katera izvaja meritve aerodinamičnega premera in števila prašnih delcev s t. i. optično metodo, ki uporablja fotometer temelječ na sipanju in detekciji odbite svetlobe od delcev. Ob uporabi klasičnih matematičnih operacij, kot so sistemi linearnih enačb, interpolacija, aproksimacija ter uporabi računalniškega programskega jezika »python« je izračunan časovni potek povprečne dnevne masne koncentracije različnih velikosti prašnih delcev (PM2.5 ter PM10) ter število dni preseženih mejnih vrednosti postavljenih s strani Svetovne Zdravstvene organizacije. Izračunana je tudi učinkovitost odstranjevanja povprečnih dnevnih masnih koncentracij s prezračevalnim sistemom v katerem bi se naj nahajal filtrirni sistem. Časovni potek izračunanih povprečnih dnevnih vrednosti masnih koncentracij je bil grafično primerjan tudi z izmerjenimi dnevnimi masnimi koncentracijami prašnih delcev, izvedenih s strani Agencije Republike Slovenije za okolje. Izračunane masne koncentracije so bile matematično ter grafično analizirane v odnosu z učinkovitostjo filtriranja prezračevalnih ter klimatizacijskih naprav. Analizirane so bile tudi v odnosu z vremenskimi spremenljivkami, kot so temperatura, vlaga, hitrost vetra in smer vetra. S pomočjo vremenskih spremenljivk in geografske lokacije je bila izvedena tudi analiza morebitnih povzročiteljev izpustov prašnih delcev.The occurrence of air pollution with dust particles or aerosols, the chemical composition, and the causes for the formation of dust particles was theoreticaly described. Consequences and impacts on human health, the applicable technical systems and measures that regulate this phenomenon were also described. The experimental work was performed with measurements of minute average numerical concentration of dust particles. These were later conversed into daily average mass concentrations with the help of mathematical operations and expert recommendations. Measurements of aerodynamics diameter and the number of dust particles was performed with optical method using a scattering photometer. Classical mathematical operations such as system of linear equations, interpolation, approximation and programming language »python« were utilised to calculate the movement of daily average mass concentration of dust particles (PM2.5 and PM10) through time and the the number of days that mass concentrations were exceeding the limit values set by World Health Organization. The movement of calculated daily average mass concentrations through time were graphically compared to measured daily average mass concentrations from Slovenian Environment Agency. Calculated daily average mass concentrations were mathematically and graphically analyzed in relation to filtration effectiveness of ventilation and air-condtioning systems. They were also analyzed in relation to weather variables such as temperature, humidity, wind speed and wind direction. With the help of weather variables and geographical location an analysis of potential dust release agents was carried out