Energieffektivisering av modern tillbyggnad till äldre skola
fallstudie från Österbyskolan i Österbybruk
The Swedish government has introduced a goal to reduce the energy intensity by 20% to the year 2020. To reach this goal actions need to be taken throughout the energy sector which includes residential and commercial buildings. This thesis considers the possibility to reduce the energy usage in a building located close to Uppsala. The analyzed building is a combined office, cafeteria and entrance and was completed about half a year before this project started. Therefore the measures presented for a more energy efficient building are presented as measures for future constructions.Simulations have been made in VIP-Energy, a dynamic energy calculation program. The measures that have been evaluated are added insulation to roof and walls and change of windows to those with a better U-value. The results showed that the added insulation is not recommended because of the small savings compared to the investments. The use of better windows, on the other hand, would be economically viable according to the results. The better windows reduced the energy consumption by 4 MWh/year which gave a pay-back time of 16 years.Alternative energy supply systems for the studied building are also presented. The analyzed systems are pellet boiler, solar heating and two types of pre-heating/pre-cooling of ventilation air with ground heat. The most viable of these alternatives were the pre-heating/pre-cooling of the ventilation air with underground ducts which had a pay-back time of 21 years.