No description available.

Abstract Purpose: The issue that this report addresses revolves around sweep-salting of footways and cycleways. More specifically, it focuses on the fact that large differences in elevation can lead to varying land surface temperatures, which, in turn, complicates winter maintenance when using the sweep-salting method. With Jönköping as basis of study, the aim of this report has been to examine the level of knowledge regarding sweepsalting of footways and cycleways in Sweden, this to show optimization possibilities to a developed sweepsalting in Jönköping, taken into account the height differences prevailing in the city.   Method: To obtain data, structured and semi-structured interviews have been carried out. All the interviews have been done and recorded via telephone calls and the interview questions have been emailed to the respondents in advance. The structured interviews have been targeted at four municipalities and the semi-structured interviews have been targeted at two concerned governmental bodies. Parallel to the interviews, three documents have been subject of analysis: Karlstadslaken by Tomas Stomberg, GCM-handboken published by Trafikverket, and Vinterväghållning och expertsystem – en kunskapsöversikt by Magnus Ljungberg. Findings: Sweep-salting as high winter maintenance method is a complicated task. It should be comprehensive, reliable, and conducted hastily over long distances and fairly large areas. It is a relatively new method and knowledge is, as of yet, limited. In the interviews, it became evident that municipalities largely are self-managing in this matter, but that a desire for more intermunicipal collaboration exists. Primarily, municipalities see the need of a governmental framework on how to conduct sweep-salting most efficiently.  De-icing is not carried out the same way in the north of Sweden as it is in the southern parts of the country. In the north of Sweden, the primary focus is snow clearance, and sweep-salting is only carried out when temperatures allow for it. In the south of Sweden, on the other hand, where temperatures often fluctuate around zero degrees Celsius, and snow quantities are manageable, sweep-salting is more prioritized. Implications: Besides keeping track of aerial and land surface temperatures, it is important to control the dew point, in order to apply the appropriate maintenance methods on the most crucial areas of footways and cycleways, at the right time. It is also important to stay updated on municipalities’ development of sweep-salting. Limitations: The economic aspect of sweepsalting is not considered in this study, neither is the perspective from cyclists nor pedestrians of the results of sweepsalting. The study would probably have reached a better result if more municipalities would have been included. Keywords: Brine, DYS spreader, Height difference, Latitudes, PC path, Plate spreader, Surface temperature, Sweepsalting, VVIS Puck.

Since climate change increases and changes constantly, it contributes to higher average temperatures, ice melting and has a great impact on our ecosystem. This will then lead to a warmer climate, which means increased precipitation and milder winters. One of the reasons to climate change is urbanization, meaning people moving to the cities. To succeed in changing the climate, international cooperation and common goals are required. At the northern part of Brynäs, in the municipality of Gävle, work is currently in progress around the area where the factory of Läkerol was once standing. The area continues to be rebuilt and the outcome will eventually be called Godisfabriken. There, amongst other, a car park will be built for the newly built homes. The aim of this study is to compare metal roofs, grey concrete roofs and green roofs within the two aspects of stormwater management and temperature. Then analyse which alternative of these three roofs would be most advantageous for the car park of Godisfabriken.   The focused roofs are green, metal and concrete. A green roof is when it's completely or partly covered by a layer of vegetation and metal roofs are different sheet roofs with steel and aluminium-zinc. Grey roofs are made of concrete which works as both floor and ceiling. A building's roof affects which air temperature the surroundings has with its slope, vegetation and surrounding buildings. Another problem with urbanization and a warmer climate is stormwater management, which means rain and melted snow from roofs, parking areas and other hard surfaces.   The method includes a literature study and calculations. The literature study gave research on temperature for all roofs as well as stormwater management for green roofs. Calculations were made for stormwater management and temperature with its flow, absorption, reflectance and heat transfer.   The literature study and the calculations showed that green roofs have a high SRI value of 80 while the remaining roof is at around 40. The higher SRI, the lower surface temperatures on the material. This is proven in both methods when green roofs according to the literature study received a maximum surface temperature of 38 °C and 48 °C. According to the literature study green roofs can preserve more than 50 % of the rainwater. They also had a water flow rate of 1.97 l/s, which is less than half of what the metal roof got in the calculations. Since green roofs had both low air and surface temperatures, as well as longer drainage times and most absorbed water, green roofs are a more suitable choice than metal and grey concrete. / Eftersom klimatförändringarna förändras och konstant ökar bidrar det till en högre medeltemperatur, att isen smälter och att ekosystemet påverkas. Detta kommer då leda till ett varmare klimat vilket medför ökad nederbörd och mildare vintrar. En av orsakerna är urbanisering vilket betyder att människor flyttar till städer. För att lyckas förändra klimatet krävs internationellt samarbete och gemensamma mål.   Vid norra Brynäs i Gävle kommun pågår just nu arbete runt området där Läkerolfabriken en gång stod. Gamla Läkerolområdet kommer slutligen bli Godisfabriken. Där kommer det uppföras ett parkeringshus till det nybyggda bostäderna. Syftet med denna studie är att jämföra metalltak, gråa betongtak och gröna tak inom de två aspekterna dagvattenhantering och temperatur, därefter analysera vilket alternativ av dessa tre tak som skulle vara mest fördelaktigt för Godisfabrikens parkeringshus.   De fokuserade taken var grönt-, metall- och betong tak. Ett grönt tak är då taket är helt eller delvis täckt av ett lager vegetation. Metalltak är olika plåttak med stål och aluminium-zink, gråa tak syftar på betongbjälklag som fungerar både som golv och tak. En byggnads tak påverkar vilken lufttemperatur omgivningen har, även takets lutning samt växtlighet och byggnaderna runt om. Ett annat problem med urbanisering och varmare klimat är dagvattenhanteringen, vilket innebär regn- och smältvatten från bland annat tak, parkeringsytor och andra hårdgjorda ytor.   Metoden innefattar en litteraturstudie samt beräkningar. Litteraturstudien gav forskning om temperatur för samtliga tak samt dagvattenhantering för gröna tak. Beräkningar genomfördes för dagvattenhantering och temperatur med dess flöde, absorption, reflektans och värmeöverföring.   Litteraturstudien och beräkningarna visade att gröna tak har ett högt SRI (Solar Reflectance Index) värde på 80 medan resterande tak låg på runt 40. Ju högre SRI desto lägre yttemperaturer på materialet. Detta bevisas i båda metodvalen då gröna tak enligt litteraturstudie fick en maximal yttemperatur på 38 °C och 48 °C enligt beräkningarna. De hade även ett dagvattenflöde på 1,97 l/s, vilket är mindre än hälften av vad metalltaken på 4,93 l/s fick vid beräkningarna och kan enligt litteraturstudien bevara mer än 50 % av regnvattnet. Då gröna tak hade både låga luft- och yttemperaturer samt längre avrinningstid och mest absorberat vatten visar det att gröna tak är ett mer lämpligt val än metall- och gråa betongtak.

Glass has sophisticated front properties and are used as facades in high buildings. During cold periods, these glass facades could cause thermal discomfort, due to cold downdraught. Cold downdraught can be countered by placing heaters under glass surfaces. Nowadays technology offers highly insulating windows, which is why there is an interest to investigate the indoor climate with only underfloor heating. The research in this area is limited, and few empirical methods are available. Theoretical analysis has begun but it still brand new. The aim of this investigation was to present the thermal indoor climate influenced by various parameters, such as outdoor temperature, U-value and the glass height. The results were also meant to be used as reference tools in future projects. A reference building was modeled in simulation software called CFD Star-CCM+. The assignment was initiated by Incoord, a leading consulting company in energy, indoor climate and installation planning. The results showed that the air velocity increases with decreasing outdoor temperature and decreases with increasing thermal insulation (lower U-value). At the edges of the glass the air velocity becomes twice as large compared to the velocity of the air in the middle of the atrium. The air velocity (maximum and average) at 0.1 m above the floor is always higher than at 2.0 m. The lowest air velocities start from about 0.25 m/s at 0 ℃ and reaches to 0.60 m/s at -20 ℃. That means these air velocities are too high for what is accepted as a good indoor climate, where the maximum allowable air velocity is 0.15 m/s. The outdoor temperatures and the glass facade’s U-value also have an effect on the surface temperature of the glass facade. This decreases the surface temperature with decreased outdoor temperature, and the surface temperature increases at lower U-value. The height of the glass facades proved to affect both the air velocity in the occupied zone and in the glass surface temperature. The air velocity increases with the glass’ height. The increase is higher at 0.1 m than at 2.0 m above the floor. The result shows also that the average air velocity is lower than 0,15 m/s at window height lower than 5 m. But, at the same height the maximum air velocity is higher than 0.3 m/s. The surface temperature of the glass facades increases with the glass’ height. This is because the indoor heat transfer coefficient increases with height. The outdoor heat transfer coefficient is a function of the wind speed and was assumed to be constant. The underfloor heating, which is represented in the simulations with a floor surface temperature of 27 ℃, is not enough to maintain a good indoor climate in any of simulations. The results of this thesis showed a strong relation between indoor climate, outdoor temperature, U-value and the glass height. This study also showed that the floor heating is not enough to counteract the cold draft during extreme cold periods, in high glass buildings. The presented results can be used as a reference tool for the assessment of air velocities and surface temperatures, in similar high buildings.

As urbanization and global warming increase, an increasing importance is set on that urban planning processes take the possible effects of urban heat islands into account. In order to provide local city planners with site specific knowledge of the current situation in Stockholm, this study has explored the intra-urban heat island effect in Stockholm municipality by identifying major problem areas as well as addressing the statistical relationship between temperature and factors relating to land cover and urban planning strategies. Remotely sensed land surface temperature (LST) and the Swedish National Land Cover Database (NMD) have formed the data basis for the analyses that were carried out using GIS. The LST and land cover information have been extracted from randomly placed circle polygons in order to create a sample for the statistical analyses.  The results show that there exist differences in temperature within Stockholm municipality, both within the municipality as a whole and between various urban characters. In both cases, land cover is identified as an important, but not sole, factor to explain the differences. On land areas, artificial non-vegetated surfaces and forest is identified as the land cover classes of most relevance when it comes to the urban heat island effect. For both land cover classes, a strong correlation to LST is seen. Even though certain uncertainties and limitations are embedded in the data as well as in the method choices, the study can conclude in that the urban heat island effect is present in Stockholm municipality and that it can be derived from both land cover and urban characters. / I takt med att urbaniseringen och den globala uppvärmningen ökar kommer högre krav ställas på att stadsplaneringen tar hänsyn till de effekter som väntas uppstå kopplat till urbana värmeöar. I syfte att bistå lokala stadsplanerare med platsspecifik kunskap om den nuvarande situationen i Stockholm har den här studien utforskat intraurbana temperaturvariationer i Stockholms stad genom att identifiera de mest utsatta områdena samt genom att undersöka det statistiska sambandet mellan temperatur och faktorer kopplat till marktäcke och stadsutformning. Markens yttemperatur uppmätt från satellit och Nationella marktäckedata (NMD) har utgjort det främsta dataunderlaget för analyserna som genomförts med hjälp av GIS. Genom att extrahera information om yttemperatur och marktäcke från slumpmässigt placerade cirkelpolygoner kunde ett urval till de statistiska analyserna skapas.  Resultaten från studien visar att det finns skillnader i temperatur inom Stockholms stad, både inom kommunen som helhet och mellan olika stadsbyggnadskaraktärer. I båda fallen kan marktäcke identifieras som en viktig, men inte ensam, faktor till att förklara skillnaderna. På landområdena identifieras exploaterad mark och skog som de marktäcken med störst betydelse när det kommer till urbana värmeöar. För båda marktäckena ses i studien en stark korrelation till yttemperatur. Trots att vissa osäkerheter och begräsningar kan kopplas till både använd data och de metoder som använts kan slutsatsen att effekten från urbana värmeöar finns i Stockholms kommun dras. Dessutom kan konstateras att effekten kan härledas både till marktäcke och stadsbyggnadskaraktär.