The main topic of this project is to do an energy study of the Mariners’ Church, ‘Sjömanskyrkan’, placed in the Centralplan of Gävle, Sweden. This is an old building built in the late 1800’s by the evangelic-lutheran missionaries and nowadays is used to realize different cultural activities such as concerts, meetings, workshops…

Energy is one of the most important points in the actual society. The fact that common energy sources are being depleted and the use of these resources produces a lot of contaminants have brought some many international crisis and conflicts. A big use of oil fuels can influence the government behavior and condition its laws and regulations. Nowadays, the majority of the countries want to reduce their fossil energy sources dependency, e. g. Sweden designed an energy commission in 2005 to make a report on how these uses of petroleum, natural gas and ‘fossil raw materials’ can be reduced until 2020. This project wants to follow this direction, providing some energy savings through the investment and renewal of old public buildings.

The aim of this project is to know how much and in which way this building uses the energy, locating its strong and weak points, and point out some different energy efficiency measures to improve the situation.

First of all, an energy balance has been realized. In the part of the heat gains the total energy use is 274 MWh / year. On the other hand the energy losses give a quantity of 273 MWh / year. The differences between both are the losses by infiltration, 1MWh / year. Most of this energy is lost because of the transmission, about a 95% of the energy losses. The age of the building and its old materials are the main reason for this out of proportion percentage. That’s why the main efficiency measures are referred to this part.

After this first analysis, some efficiency measures have been carried out. The most important are referred to the structural elements like walls, windows, roof and floor. All of these procedures can save 45% of the energy losses. This is evidence that old buildings and this in particular, are really bad insulated and have a lot of heat leakages. Also some behavior recommendations are given, like maintenance works and lightning improvements.