Energieffektivisering av byggnader

Sammanfattning: A large part of the energy consumption in Sweden comes from dwellings. To achieve the political climate goals this sector needs to decrease its need for energy. The reason is not only political it is also an economical matter. There are some things that can be done to save energy and the purpose with this report is to investigate these actions. The literature study and the result have developed through literature search, calculations and field studies of two houses with different year of construction. Particularly has the climate shell of the houses been investigated with an IR-camera and the air leakage has been measured with a blowerdoor. The focus area of the energy savings has been heat. The things that has been investigated is additional insulation, replacement of old windows and doors with new ones who are more efficient and to seal the window frame and around the doors. The study is limited and will not look at all areas of energy savings. Ventilation and other energy consuming activities in the houses will not be investigated. Additional insulation was a good method to save energy but it was expensive and in an economical point of view it might be hard to make a profit out of it. It is quite complicated to do an additional insulation because the linings in the windows and doors needs to be removed and it changes the appearance of the house a lot. Replacements of doors and windows are also a bit complicated but not as much as the additional insulation. When changing the windows the U-value is important. It is only recommended to change windows if the new one has a lot lower U-value. The calculation in the report shows that even if there is a large different in U-value between the old and new window it is still hard to make an economical profit. The study shows that the windows themselves are not always the problem. It is common that it’s not completely sealed around the windows and doors. When this is the problem is doesn’t matter how good the windows are. A cheap alternative is then just to improve the sealing around the windows and doors.