Verifiering av beräknad energiprestanda för flerbostadshus byggda år 2007-2009
EnergiberäkningEnergideklarationFlerbostadshusNormalårskorrigeringSpecifik energianvändningUppföljningVerifiering
The building industry consumes approximately 40 % of the total energy consumption in Sweden, where the using stage is dominating with 80 %. There is a lot of work in progress to reduce energy use in the building industry, and the demands from authorities regarding energy use increases. As a part of this work Building and planning department of Sweden has established a requirement that has been applied since 2006, and restricts a maximum energy use for buildings.The requirement includes that an energy simulation must be done in advance to demonstrate that it is possible to meet the demands.Reality is however more complex than an energy simulation program, that frequently underestimates the energy use of buildings. The purpose of this thesisis to study and analyse deviations between estimated and actual energy use in modern apartment buildings. The study includes four apartment buildings in Stockholm, Gothenburg and Jönköping that were built in 2007-2009. The thesis is done in collaboration with Riksbyggen. Riksbyggen have built and manage the buildings.The energy simulations have been executed in Enorm 2004 and VIP+ 5.2. All the buildings show a higher energy use than were simulated. The deviations are small for the overall use, between 1 and 8,6 %, except for one of the building with a deviation of 20 % higher energy use than simulated. For individual measurements however, there are large differences. The larges deviation is for heating, which were underestimated, up to 50 %. The main reasons of deviation are an underestimation of indoor temperature and no consideration of manual ventilation and culvert losses. Hot tap water on the other hand has been overestimated up to 57 %. One reason is high standard values when calculating.The whole difference does not necessarily depend on miscalculations. Errors can also occur when separate measurement of hot water is not available and an assessment must be made by hot water proportion of total water consumption. The result is the basis for following conclusions and recommendations:A higher indoor temperature than the current recommendation of 21 °C should be considered when calculating.Use of standard values for tap water should be made with caution, as these tend to be exaggerated.A manual ventilation supplement of 4 kWh/m², year has been proven to reduce deviations in heating requirements.Comparison between calculated and declared energy use should be made by individual measurement instead of total energy use.IMD (individual measurement and billing) provides, in addition to energy savings, a more reliable follow-up.