Energy audit of a single-family detached house with district heating in Sweden

Sammanfattning: As energy prices keep increasing, energy efficiency measures have come to the spotlight, especially in the residential sector. In this context, energy audits appear as powerful tools in order to assess the energy use and cost of energy of a dwelling, and identify possible energy saving measures that increase the energy efficiency and reduce costs. This work performs an energy audit of a single-family house (SFH) built in the 1970s which uses district heating, located in Gävle, Sweden. An empirical and quantitavive approach is followed, where energy data from the bills of 2022 together with on-site ventilation measurements is combined as a way to determine the energy inflows and outflows of the dwelling. Results concluded that the ventilation needs to be improved as a way to meet the Swedish building regulations. In addition, the energetic situation could be improved by means of the installation of solar photovoltaic (PV) modules to cover part of the electricity demand and solar thermal collectors to cover part of the domestic hot water demand. These measures would decrease the costs of the energy bills 4689 SEK/year at the time they would provide a source of renewable energy. The replacement of windows was also studied, concluding the payoff time to be excessively long to be accepted.