| Abstract [eng] |
In this master's thesis, an alternative ventilation system is investigated using the life cycle assessment methodology. The evaluation is performed for three types of duct systems: the first duct system is traditional, made of metal – galvanized steel; the second system offers an alternative to metal ducts – it is a fabric duct made from polyethylene terephthalate; the third is a recycled fabric system, produced from recycled polyethylene terephthalate bottles. Fabric ducts represent the newest technology in duct systems and are studied as a more efficient alternative to metal systems. These fabric ducts utilize an insulating fabric that facilitates air transport to desired areas of a building. This fabric limits energy losses in undesirable locations and removes the need for additional coating, reducing permeability. Fabric ducts are also significantly lighter than traditional sheet metal ducts, thus eliminating the need for additional support components, which leads to cost reduction. The thesis discusses the peculiarities and principles of ventilation systems, metal and fabric ducts in ventilation systems, and life cycle assessment. The study applies life cycle assessment methodology – a systematic and comprehensive method used to evaluate the environmental impact of a product, service, or process throughout its entire lifecycle – from raw material extraction to disposal. Life cycle assessment is conducted in accordance with international standards ISO 14040:2006 and ISO 14044:2006. A functional unit defined for the study was the ventilation of a 100 m2 space over a 20-year period, and the system boundaries were defined. The life cycle assessment revealed that metal ducts have the greatest environmental impact in categories such as respiratory inorganics, ionizing radiation, ozone layer depletion, terrestrial acidity, aquatic acidification, aquatic eutrophication, global warming, non renewable energy, and mineral extraction. Fabric ducts showed the greatest impact in categories related to carcinogens, non-carcinogens, respiratory organics, aquatic ecotoxicity, terrestrial ecotoxicity, and land occupation. Meanwhile, recycled fabric ducts had the least environmental impact across all analyzed life cycle assessment categories. Normalized results also revealed that recycled fabric ducts have the least environmental impact. Metal ducts exhibited a 9.7 times greater impact on human health and a 105 times greater environmental impact in the climate change category compared to fabric ducts. In the ecosystem quality category, all duct types had a minor impact, but the largest was caused by the fabric duct – its impact was 1.25 times greater than that of the recycled fabric duct and significantly greater than that of the metal duct. In the resource category, metal ducts also had the greatest impact. In this category, the metal duct had a 27 times greater environmental impact than the fabric duct. Recycled fabric ducts had negative valuesfor climate change and human health categories. Tu sum up, it was determined that the recycled polyethylene terephthalate duct has the least environmental impact compared to fabric and metal ducts. |
