Analys av köldbryggor, fönsterplacering och värmesystem för ett låg-/plusenergihus

Environment and energy are two factors that have become more important as thedevelopment in general is increasing over the world. Low-energy houses havebeen on the market for a while now, and the development of buildings is movingtowards houses that can produce energy both to deliver and to supply the houseitself. As the thickness of the walls increases it becomes more important to reducethe thermal bridges among construction details, for example connection betweenwall and slab.To understand how to design and construct these buildings, knowledge aboutmaterial, thermal bridges, building details, climate and heating systems is required.In this thesis, analyzes have been done that concerns heating systems that aresuitable for a low energy house with help from references to similar projects.Together with the Swedish company Trivselhus general principles for thermalbridges have been developed, these principles are based on calculations by handand by using software called UNorm 2011-1. The result shows a critical partamong the connection between the concrete slab and the wall. Also the joist isreally important to make sure it is dense. To reduce the heat flow in this criticalarea, it makes sense to separate the joists and insulate between them. For thermalbridges around the windows, the results of calculations, both by hand and byUNorm, showed that thermal bridges are greater in a thick wall. In a thick wall theheat flow is slower and the wall is perceived as cold. This has not much effect onthe actual indoor temperature, but the wall may get a milder impression.In Autodesk’s Revit Architecture a sun study has been created to see if there isany difference between having the windows placed in the facade or in the innerpart of the facade. Will it make any difference for the shading of the window andhow will it affect the sun insolation and the transmission of energy in and out ofthe window? When the window is further into the wall, the wall creates a box thatincreases the shading of the window. Based on this result you can see that theplacing of the windows does matter. During the summertime a lot of solar energywill be lost if the window is placed further in to the facade. The transmission fromthe building, through the windows, is not that big, but the greatest difference canbe seen in the total solar insolation. A lot of energy can be extracted from the suninsolation, if you place the windows right, which is in the outside of the facade.Almost one fourth of a buildings total energy consumption of a year can bereceived from the solar energy only through the windows, if they are placed in theoutside of the facade.