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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Primary and secondary emissions from green building materials : large chamber experiments

Gall, Elliott Tyler 20 September 2010 (has links)
Indoor sources of air pollution generate a large fraction of overall human exposure to airborne pollutants. Materials used in buildings have been shown to be a major contributor to indoor air pollution, with green building agencies setting guidelines limiting their primary emissions. However, such guidelines neglect secondary emissions resulting from chemistry occurring in indoor spaces. Furthermore, limited knowledge exists regarding ozone reactions and green building materials. This study focuses on the primary aldehyde emissions, ozone deposition velocity, and secondary emissions from three green building materials: recycled carpet, sustainable ceiling tile, and low-VOC paint and primer on recycled drywall. Ozone reactions resulted in secondary aldehyde emissions ranging from no increased secondary emissions to 237 µg m-2 hr-1. Modeling results suggest that these emissions can cause concentration increases beyond odor thresholds. / text
2

Applicator Exposure to Glycol Derivatives and Total Volatile Organic Compounds during the Application of Spray Polyurethane Foam Insulation

Kaniuga, Michael Brian 31 October 2014 (has links)
There is currently high demand for new building materials which are considered "environmentally friendly" or "green" for both new construction and renovations. Spray polyurethane foam (SPUF) insulation has gained significant acceptance by both consumers and the construction industry due to its high R-value, which results into significant energy savings among other things. Despite its acceptance by consumers and the construction industry, consideration must be given to potential chemical exposures to applicators installing these products. This study sought to determine, through quantitative experimentation, if there was a release of glycol derivatives including, diethylene glycol (DEG), ethylene glycol (EG), and propylene glycol (PEG), during the application of SPUF. In addition, total volatile organic Compounds (tVOCs) and various environmental parameters were also collected during this research. This study utilized a two-component small-scale SPUF kit manufactured by the Dow Chemical Company, known as the FROTH-PAK™ kit. This specific kit is typically used by the construction industry to fill cavities, cracks, floor and wall penetrations, and expansion joints of buildings. In order to determine the presence of these glycol derivatives, personal breathing zone samples were collected during the application of the SPUF during three application trials. Glycols derivatives were measured using active sampling techniques. Supplementary parameters including tVOCs, ambient and wet-bulb temperature, relative humidity, carbon monoxide, and carbon dioxide, were measured using direct-reading techniques. During this study several modifications were made to the work area and the air sampling methodology to assist in verifying the presence of the glycols and the conditions in which they may be present in the air during the application of SPUF insulation. All samples were sent to an accredited laboratory and were analyzed by the Nation Institute of Occupational Safety and Health Method 5523. During this study, measurable amounts of diethylene glycol and propylene glycol were detected in two of the trials in which no ventilation in the work area was utilized. During one trial in which a work area ventilation system was utilized, none of the glycols were detected in the laboratory analysis above the limit of detection given the analytical method. Ethylene glycol was not detected in any of the samples submitted for analysis. The results for the tVOC measurements were inconclusive. Based on the results of the air sampling, it is likely that exposure to diethylene glycol and propylene glycol may occur under certain conditions. However, due to the limited number of samples and the variation between the samples collected in this study, a generation rate or concentration buildup estimate for comparison of the OELs was not conducted. These conditions include the quantity of ventilation used during application, the application duration, and proper operation of the SPUF application equipment. Based on the results, there is evidence that additional research may be needed in this area.
3

Impacts of a clay plaster on actual and perceived indoor air quality

Darling, Erin Kennedy 03 October 2011 (has links)
Passive removal materials (PRMs) are building materials or furnishings that can effectively control indoor pollution without substantial formation of chemical byproducts and without energy penalty. To assess clay wall plaster as an effective PRM for improving air quality by controlling ozone, perceived air quality (PAQ) was determined in the presence of eight combinations of an emitting and reactive pollutant source (new carpet), clay plaster applied to gypsum wallboard, and chamber air with and without ozone. A panel of 18 to 23 human subjects assessed air quality in twin 30 m3 chambers using a continuous acceptability scale. Air samples were collected immediately prior to panel assessment to quantify concentrations of C5 to C10 saturated n-aldehydes and two aromatic aldehydes that are commonly produced by reaction of ozone with carpet. Perceived Air Quality was most acceptable and concentrations of aldehydes were lowest when only clay plaster or both clay plaster and carpet were present in the chambers without ozone. The least acceptable PAQ and the highest concentrations of aldehydes were observed when carpet and ozone were present together; addition of clay plaster for this condition improved PAQ and considerably decreased aldehyde concentrations. Ozone deposition and byproduct emissions of the clay wall plaster were also assessed using 48 liter stainless steel chambers. Clay plaster applied to gypsum wallboard that had been exposed in a test house (UTest House) for one year effectively removed 88% of the ozone, and emitted high aldehyde concentrations when exposed to high purity air that did not increase when the material was exposed to ozone. The outcome of these experiments leads to speculation that the clay plaster adsorbed contaminants in the test house and then re-emitted them upon exposure to clean air in the small chambers. / text
4

The Indoor Environment of Green versus Non-Green Buildings

Coombs, Kanistha C. January 2015 (has links)
No description available.
5

Hampafiberns potential för en hållbar utveckling : En jämförande studie mellan hampafiberisolering och konventionella isoleringsmaterial ur ett livscykelperspektiv / The potential of hemp fibre insulation for a sustainable development : A comparative study between hemp fiber insulation and conventional insulation materials from a life cycle perspective

Svedin, Daniel, Wennberg, David January 2021 (has links)
Världens fokus på hållbar utveckling är större än någonsin tidigare, och konstruktionssektorn ansvarar för upp emot 25 till 40 procent av de globala koldioxid emissionerna. Ett av nyckelmaterialen för att öka en byggnads energieffektivitet är isoleringsmaterialen. Syftet med detta kandidatexamensarbete är att utvärdera GWP:n av hampafiberisolering jämfört med de två marknadsledande isoleringsmaterialen, mineralull och cellplast.  GWP:n av de tre isoleringsmaterialen beräknas efter att vardera isoleringsmaterial har blivit placerat i ett envåningshus med storleken 30 m2. Livscykelanalysen för byggnader används sedan som bakgrund för att beräkna GWP:n av de tre byggnaderna. De beräknade kategorierna för GWP:n av byggnaderna är: råmaterial, transport, produktion, konstruktion samt energianvändningen. Byggnaderna antas ha en inomhustemperatur på 20°C och har blivit konstruerade i Stockholm, Sverige.  Utan överraskning var hampafibern det isoleringsmaterial som hade lägst GWP i kategorierna; råmaterial, produktion och konstruktion. Däremot på grund av hampafiberns mindre optimala termiska konduktivitet jämfört med de andra isoleringsmaterialen var byggnaden med hampafiberisolering den minst energieffektiva.  Trots den lägre energieffektiviteten visade sig byggnaden med hampafiberisolering vara den med lägst GWP under en 30 årsperiod, förutsatt att förnyelsebara energikällor användes. Överraskande nog, var däremot källan från vart elektriciteten kom mycket viktig för att avgöra byggnadernas GWP. När den svenska elmixen från Boverkets klimatdatabas användes var skillnaden i GWP mellan de olika byggnaderna marginell. Användes istället förnyelsebara energikällor i form av vindkraft, var hampafiberisoleringen det mest fördelaktiga isoleringsmaterialet ur ett miljöperspektiv. / The world's focus on global warming has grown larger than ever before, and the construction sectorisresponsibleforupwardsof 25to40percentoftheglobalcarbonemissions.Oneof the key materials to increase the energy efficiency of buildings are insulation materials. The purpose of the thesis is to evaluate the global warming potential of insulation made out of hemp compared with the two leading insulation materials on the global market, Mineral wool insulation & EPS.  The global warming potential of the three insulation materials are calculated whilst each is placed in a 30 m2 one-story house. The life cycle assessment (LCA) of buildings is used as background to calculate the global warming potential of each of the three buildings. The calculated categories for the global warming potential are: raw materials, transportation, production, the construction phase, and energy usage in the building. The buildings are assumed to have an inside temperature of 20°C and have been constructed in Stockholm, Sweden.  To no surprise the hemp fibre insulation material had the lowest global warming potential out of the three materials during the raw material, production and construction phase. However due to the less optimal value of thermal conductivity for the hemp fiber insulation compared to the other materials, the energy efficiency in the building using hemp fibre insulation was comparatively the worst.  However, the building using hemp fibre insulation could be concluded as the one with the least global warming potential during a 30 year usage if the correct energy sources were used. Surprisingly enough it turned out that the source of electricity was vital for the global warming potential. When using the Swedish electricity mix found in Boverkets Climate database the difference between the buildings was marginal. If renewable sources in the form of wind power were used instead of the national mix for electricity the differences were more noticable and the building using hemp fiber as insulation was less impactful the lower the global warming potential of the energy source was per kWh.
6

Ekologiškų namų racionalaus varianto intelektinės sistemos kūrimas / Development of an Intelligent System for Rational Variant of Eco-friendly Houses

Verikas, Vaidas 01 July 2011 (has links)
Baigiamajame magistro darbe nagrinėjamos ekologiškos statybinės medžiagos, analizuojami namo dalių konstrukciniai variantai, statant namus iš šių medžiagų. Taip pat sudaroma kompiuterinė sistema, padedanti vartotojui išsirinkti racionaliausią ekologiškų medžiagų panaudojimo variantą. Darbą sudaro trys dalys. Pirmojoje dalyje apžvelgiama ekologiškų statybinių medžiagų samprata, pagrindiniai principai, aprašomas statybinių medžiagų gyvavimo ciklas, aptariama aplinkai nekenksmingų medžiagų situacija Europoje. Antrojoje dalyje plačiau aprašomos gamtai nekenksmingos statybinės medžiagos, galimi tokių medžiagų konstrukciniai variantai. Analizuojami sienų, stogo dangos, šilumos izoliacijos ir šildymo sistemos pritaikymo galimybės statant ekologišką namą. Trečiojoje dalyje nagrinėjamas praktinis ekologiško namo konstrukcijų pritaikymo modelis. Sudaroma alternatyvų ir kriterijų sistema, apibūdinanti nekenksmingo aplinkai namo konstrukcinius elementus. Panaudojant kiekybinius ir kokybinius kriterijus ir galimas medžiagų alternatyvas, atliekama daugiakriterė statybinių medžiagų ir jų konstrukcijų analizė, sudaroma kompiuterinė sistema. / Ecological and environmentally friendly building materials and constructional options, that are used to build houses, are considered in this master work. It also contains the computer system enabling the user to choose the most rational option of ecological materials. This master work consists of three parts: In the first part the concept of ecological building materials and main principles are described. It also contains information about the life cycle of building materials and the situation of environmentally friendly materials in Europe are discussed. The second part describes environmentally friendly building materials and possible structural variations of such materials. It analyzes walls, roof, heat insulation and possibilities of heating system in the ecological house. In the third part the practical model of the ecological house is considered. An alternative and criteria system that describes the environmentally friendly house constructional elements is created. Using quantitative, qualitative criteria and possible material alternatives multiple criteria analysis of building materials and their construction is performed. The computer system is also made.

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