Uppvärmning har länge varit den mest energikrävande delen av bostads- och lokalsektorn i Sverige. Än idag står denna för hälften av all energianvändning. Detta har lett till att det ökande behovet av komfortkyla hamnat i skymundan. Mätningar har främst gjorts på fjärrkyla, vilken väntas öka till ca 3 TWh år 2030. Detta gör det inte helt långsökt att det skulle kunna finnas en marknad för mer småskalig och lokal produktion av komfortkyla. Arbetet har gått ut på att beräkna möjligheten att implementera ett soldrivet komfortkylsystem i en kontorsbyggnad. Två olika typer av kylsystem har undersökts. Dels ett kompressionskylsystem, drivet av el från PV-celler, och även ett absorbtionskylsystem drivet av varmvatten från solfångare. Systemen har utvärderats mot varandra med utgångspunkt i dels effektivitet men även ur ett hållbarhetsperspektiv. Ekonomisk hållbarhet har varit svårutvärderad på grund av brist på prisinformation för anläggningar av den storlek som använts i modelleringen. Från ett miljöperspektiv finns det fördelar med absorptionskyla, men denna tar även upp mer plats och uppnår en lägre total verkningsgrad. Det slutliga valet baseras troligtvis på företagets budget och det befintliga utrymmet för anläggningen. Studien visade att den mest effektiva åtgärden var avskärmning av fönster, varpå en kombination av solpaneler och lagringskapacitet bör väljas för att uppnå det uppsatta kravet på inomhustemperatur. Uppkoppling till elnät och fjärrvärmenät kan även förbättra säkerheten och effektiviteten hos systemet. / With an increasing demand for cooling in Swedish office buildings, as well as a growing need for sustainable energy solutions, solar-powered indoor cooling looks set to become an increasingly interesting topic. The aim of this study has been to model a typical office building using local climate and insolation data for Stockholm, and examine the potential of utilising solar energy to cool this building to acceptable temperatures throughout the year. Two systems were examined: a compression-chiller powered by electricity supplied by PV-panels, as well as an absorption chiller powered by hot water from solar collectors. It was found that both systems could achieve acceptable indoor temperatures in combination with shading of windows. Although the electric system reached a higher overall efficiency, there are a range of environmental concerns which must be taken into consideration regarding the materials used in construction and operation of such systems. Both systems could be improved by installing local energy storage capacity. It was also considered beneficial to connect each system to wider networks, such as the electricity network and district heating network, in order to secure energy supply on hot but cloudy days. This simultaneously reduces the space and investment required for energy storage.

´Kandidatexamensarbete inom Samhällsbyggnad AF102X vt 17. Del 1: Teknisk beskrivning av småhus Strömma 1:30 Del 2: Fördjupningsartikel med titel Lagring av egengenererad elenergi

This report covers the development in energy efficiency regarding apartment buildings inSweden. The purpose was to investigate the energy efficiency measures done in the last 20 years. The chosen subjects were heat supply, domestic hot water, insulation, windows and ventilation. Each subject was thoroughly investigated. Regulations were compared to measures taken. The chosen subjects have been examined regarding energy efficiency. However, the largerchanges in each area happened as a result of the oil crisis in the 1970’s. The measures done inthe last 20 years mainly focuses on the behaviour of the resident. Energy efficiency in the futuremainly focuses on technology to help the user save energy without changing their behaviour. There are further technical development opportunities regarding heat supply.

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Allt fler flyttar till Sveriges stadskärnor och förtätning ligger i tiden till den samtida bostadsbristen. Parallellt till detta nutida problem finns gott om äldre murverkshus. Våningspåbyggnad av dessa massiva murverksbyggnaderna kan intuitivt uppfattas som lämpliga och okomplicerade projekt. Bakom fasaden gömmer sig dock ett byggnadsmaterial olikt från dagens. Genom denna studien har tre referensobjekt av äldre murverkshus analyserats. Gällande hållfasthetsegenskaper, bärförmåga i byggnaden och hur ändring av byggnaden avses eller har utförts. Med tanke på att byggnadstekniken för murverkshus under sent 1800-tal inte förändrades särskilt mycket kan generella beskrivningar av stommens befintliga uppbyggnad göras. Däremot måste en ha eller införskaffa förståelse för egenskaperna i dåtidens mursten och murbruk vid projektering av en påbyggnad. Det finns flertalet analysmetoder för murverk och tillvägagångssättet för insamling av de okända egenskaperna kan vara komplicerade och svåra att tolka. När det gäller analysen av en byggnads bärförmåga kan programvaror vara till hjälp men nödvändigtvis inte för äldre murverkshus som utsätts för ökad belastning. Då ändringar i dessa hus kan skapa instabilitet och ändrat jämviktssystem. I rapporten redogörs för olika beräkningsmetoder och hur bärförmågan påverkas efter vald metod. Rapporten redogör även för viktiga faktorer vid projektering av en påbyggnad. Studien ska inte ses som en sammanfattning angående utförandet av påbyggnader, snarare är det en studie som berör tre referensobjekt och vad ett liknande projekt bör beakta. / Urbanization is an established trend in Sweden and with a simultaneous housing shortage the authorities are planning for densification of the cities. In contrast to the issue of densifying cities, there are older masonry buildings occupying the attractive central locations of the mayor city areas.  Hence, storey extensions of these massive buildings can be intuitively perceived as uncomplicated projects. Behind the facade, however, is a construction material different from today's. Through the study carried out, three reference objects of masonry structures have been analyzed. Regarding strength properties of the existing structures and aspects that should be taken into account when it comes to storey extensions. Given that the construction of masonry houses in the late 19th century does not differ very much, general descriptions of the existing structure of the body can be made. On the other hand, one must have or acquire an understanding of the characteristics of brick and mortar form the past when designing a storey extension. There are several methods of analysis for masonry and the approach of obtaining the unknown strength properties can be complicated. Even difficult to interpret. With today’s possibilities to model structures in finite element programs results can easily be produced, but if the values are representative for the existing structure’s capacity is difficult to evaluate. Considering that changes in these structures can create instability and altered equilibrium systems. This report describes different calculation methods and how the load capacity is affected by the chosen method. It also outlines important factors when designing an extension of storeys.

Intresset för att bygga med trä ökar stadigt, detta leder till utmaningar när trä ska ersätta de traditionella materialen i konstruktioner. Ofta har trä inte setts som ett tillräckligt starkt material eller ens som alternativ för exempelvis bjälklag med större spännvidder. I detta examensarbete undersöks huruvida ett samverkansbjälklag av trä och betong kan användas vid längre spännvidder samt hur egenskaperna för kopplingarna mellan träet och betongen påverkas på kort och lång sikt. För att undersöka dessa bjälklag har sex olika konstruktioner analyserats vilka innefattar både KL-träskivor samt limträbalkar. Som koppling mellan träet och betongen har skjuvförbindare som är anpassade till samverkansbjälklag och finns tillgängliga från leverantörer i Europa använts. De skjuvförbindare som analyserats är: Würth FT-förbindare med skruv Assy plus VG SFS Intec VB skruv Grovnot Samverkansbjälklagen har beräknats med hjälp av γ-metoden från Eurokod 5 samt analyserats med hjälp av finita element-metoder. Vid finita element-analyserna har RFEM från Dlubal använts och bjälklagen modellerats upp. Utdatan från beräkningarna har sedan kontrollerats med kraven från Eurokod 5 och svenska nationella val enligt EKS. Studien visar att samverkansbjälklag mellan trä och betong fungerar bra och är lämpligt för längre spännvidder, de mekaniska skjuvförbindarna som analyserats klarar kraven. / The interest in wood construction is increasing steadily, this leads to several challenges when wood is to replace the traditional materials used in different constructions. Traditionally wood has been considered as to weak and often not even an alternative for floors with larger spans. This thesis examines whether timber concrete composite flooring or TCC-flooring can be used with larger spans and how the connections between the two materials works at short and long term. To examine this, six different floors has been analysed which includes both CLT and glulam beams. The shear connectors used in the construction were chosen on two bases, it´s main purpose should be to use in TCC-flooring and that it had to be made in Europe. The following connectors were used: Würth FT-connector with screw Assy plus VG SFS Intec VB screw Notched connection To analyse the TCC-floor the γ-method from Eurocode 5 was applied and calculations was also made using finite element-methods. The finite elements-analysis were made using a software from Dlubal called RFEM and the different constructions were modelled. The results from both calculations were then compared and checked according to the demands made by Eurocode 5 and the Swedish national annex, EKS. The study shows that composite action flooring between timber and concrete works well and is suitable for longer spans, the mechanical shear connectors analysed meets the demand.

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Wooden multi-family residential houses continue to gain in popularity. Compared to concrete, wooden constructions have low mass and are subject to relatively poor sound insulation at low frequencies. In a series of Swedish research projects (AkuLite, Aku20 and AkuTimber), the correlation between the measured sound insulation in lightweight, cross laminated timber (CLT) and concrete buildings, was compared to the self-rated annoyance from the residents. Impact sound insulation, LnT,w and LnT,w+CI,50−2500, showed weak correlation with the self-evaluated annoyance. Particularly residents living in wooden houses were irritated by footstep noise generated by a sound source with significant energy content below 50 Hz. When determining impact sound insulation, reverberation time (RT) is measured and normalized to 0.5 s. Below 50 Hz, the uncertainty of the measured RT has been reported to be an issue. In this thesis, empirical studies of the spatial variation of the RT are performed in two empty bedrooms of different construction, the measurement methods ”interrupted noise” and ”integrated impulse response” are compared. The spatial variation of the RT is studied. The uncertainty, in terms of standard deviation, is not found to be larger for frequencies below 50 Hz compared to higher frequencies. The bedrooms are then furnished and the RT is measured with the integrated impulse response method, found to be favorable below 50 Hz. To what extent furniture contributed to the absorption, and thereby affected the RT, is studied. At frequencies below 50 Hz, no statistically significant difference in the absorption, due to furniture, is found. Consequently, below 50 Hz, there should be no need for the normalization of 0.5 s when impact sound insulation is evaluated. From the scientific literature, there is an evident need to develop and upgrade sound insulation prediction methods of CLT panels. A finite element (FE) model is provided, capable of predicting the airborne sound insulation of typical CLT wall configurations. Single and double CLT panels, with air and mineral wool respectively in the cavity, are studied. A 2D-3D Hybrid FE model is introduced that rotates the panels to capture a diffuse-like sound field with reduced computational time compared to a full 3D model. The purposes are to predict the weighted sound reduction indexes, Rw and Rw + C50–3150, as well as to study the response as the materials and dimensions alter. For single walls, the differences regarding Rw and Rw +C50–3150 are within ±2 dB compared to analytical calculations and laboratory measurements. For double walls, the Hybrid model can provide an indication of the airborne sound insulation and serve as a tool for relative comparisons, but due to the lack of comparative data, the absolute accuracy cannot be stated. Metamaterial, an engineered material with properties not found in naturally occurring materials, may at a later stage be added to the FE model with the aim to improve the sound insulation below 50 Hz of CLT constructions. Passive vibroacoustic metamaterial, designed according to the localized resonance principle where the eigenfrequency of the unit cell (building up the metamaterial) coincides with the wanted wave length to decrease or cancel, is of particular interest. One such example is the Mie resonator which are studied in a pilot study. Two critically coupled Mie resonators, tuned to have monopolar and dipolar resonances in the same frequency region, will produce the highest sound absorption and thereby the highest sound insulation of the CLT construction. The Mie resonator was designed to absorb sound within the 31.5 Hz octave band, the result from the pilot study seems promising.