Search

Energy price are on the way up to a high level that will not diminish in the future make us to focus more on the sustainable development for a better solution of residential houses. Passive house or low energy housing are one of the solution to make residential more environment friendly, in same time it´s a financial security using less energy, and saving money. The last 10 years in Germany and all around Europe the concept of passive house been developed, and people aim to know more about these concept that leading the market more attractive for passive houses. A passive house is a well designed building highly insulated and air tight with mechanical ventilated system for the whole building envelope that minimizes the use of energy for heating [1]. The housing company Mimer has chosen to invest in low energy consumption in every new housing project. These future plan projects are decided to use less than 75 kwh per square meter annually in purchased energy [2]. This thesis is about new constructed passive houses, and focuses on the evaluations of the temperature, and moisture condition for attic, external walls and joist. Reason for doing this investigation is to see if passive houses fulfill the building codes regarding moisture, and temperature changes, and to find in early stage suspicious changes that could affect badly on the building envelop. The aim of this study is - Moisture risk analyses of the attic, external walls and joist - Studying temperature analysis With highly insulated walls the risk for moistures extra sensitive than normal building construction. Also during summer time the comfort inside may be surprised by high indoor temperature and one solution for that could be using sun shading.

I dagens läge har energifrågorna väckt ett stort intresse i samhället. Nu fokuseras det mer på att bygga energisnålare hus. En betydande faktor som påverkar energiförbrukningen i våra hus är köldbryggor. De uppstår då ett material med dålig värmeisolering bryter igenom ett material med bättre värmeisolering. Köldbryggor är nästan omöjligt att undvika, dock går alltid att reducera. I praktiken är det ofta inte möjligt att helt undvika köldbryggor, men det finns många olika möjligheter att minska köldbryggeffekten kraftigt. Detta eftersträvas för att uppnå lägre energikostnader eftersom köldbryggor kan medföra en betydande ökning av värmeförlusten. Avgränsningen för detta examensarbete framgår av titeln Köldbryggors inverkan på isoleringsegenskaper för sandwichelement, anslutning mellan fönster och yttervägg. Den främsta metoden som används för att åstadkomma resultatet är PC-programmet HEAT2, men litteraturstudier har också använts. HEAT2 är ett tvådimensionellt värmeflödesprogram, som beräknar den värmemängd som leds genom konstruktionsdelen. Den bygger på att dela in byggnadsdelen i ett rutnät (mesh). Ju fler rutor den blir uppdelad i, desto noggrannare resultat, men beräkningen blir samtidigt mer tidskrävande att utföra. En särskild analys gjordes med och utan den dränerande skyddsplasten i fönstrets överkant då materialet skär igenom värmeisoleringen vid betongklacken. Plasten har mångfaldigt högre värmekonduktivitet än värmeisoleringen, men den är bara 1 mm tjock. Beräkningsresultaten visar att skyddsplasten gav en betydande skillnad. Currently, the energy issues brought a lot of interest in the community. Now is the focus more on building energy-efficient houses. A significant factor influencing energy consumption in our buildings is thermal bridges. They occur when a material with poor thermal insulation breaks through a material with better insulation. In practice it is often not possible to avoid thermal bridges completely, but there are many different options to reduce the thermal bridge effect significantly. This is desirable in order to achieve lower energy costs because thermal bridges can lead to a significant increase in the heat losses. The limitation of this degree project is evident from the title Thermal bridges impact on the insulation properties of sandwich panels, the connection between the windows and external walls The primary means used to achieve the results is the HEAT2 PC-program, but literature studies were also used. HEAT2 is a two-dimensional heat flow program that calculates the amount of energy passed through the part of the construction. It is based on the allocation of the construction into a mesh, i.e. a grid. The more the mesh is divided into the more accurate the results, but the calculations are at the same time more time consuming to perform. A separate analysis was done with and without the draining protective plastic in the window's top edge where the material is passing through the thermal insulation at the concrete heel. The plastic has many orders of magnitude higher thermal conductivity than the thermal insulation, but it is only 1 mm thick. The calculation results show that the plastic caused a significant difference.