Moistureproof energy efficiency of culture historic building - A case study of the E-building at LTH School of engineering

Sammanfattning: Buildings has both a cultural-historical and technical value. Buildings that were built in the 60's and 70's had relatively simple energy requirements compared to today. A large part of these buildings need to be renovated. Culture-marked buildings makes the process more difficult due to the cultural- historical value. This means no exterior work can be done, the retrofitting energy efficiency measures need to be behind the facade. When insulating interior new problems occur. The wall gets colder and the moisture condition might reach critical levels. To counter the decrease of living area, while reducing energy consumption you have to acknowledge the importance of materials. They need to be effective and have a high moisture resistance. Methods to implement this are Aerogel insulation and vacuum pad insulation (VIP). These are proved to be the most effective insulation material on the market today. The materials have an extremely low lambda value, which means that you do not intrude as much on the living area when insulating the inside. VIP is almost completely resistant to moisture impact, while Aerogel has a critical relative humidity limit of 80%. Various proposals were developed in this report for the existing wall on how to reduce the heat emission through the wall. Hand and HEAT 2 calculations where used to determine U-values and thermal bridges. To ensure that the moisture load did not exceed the critical moisture levels of the materials, we used the program WUFI where different moisture simulations were made. The objectives were to reduce the U-value to BBRs construction requirements without exceeding the critical moisture levels of the materials. The original wall had a high U-value of 1.25 W/m2K which we wanted to reduce to 0.18 W/m2K. The different moisture simulations we made showed that the relative humidity was too high in both the insulation and brick. We came up with another way to reduce the relative humidity and water content by hydrophobing the facade, however, we did not managed to reduce the U-values to the BBR's requirements. U-values using Aerogel and VIP ended at 0.2 W/m2K, which were relatively good values compared to the original wall. Including the thermal bridges the U-value increased to 0.29 W/m2K for the suggested solutions.