Building Physics Tools: Needs, Use and the Lack of Use in the Building Process. Modelling Non-Isothermal Moisture Flow and Frost Penetration

Sammanfattning: Despite advances in material science, computers and building technology, building failures related to building physics continue to occur. These failures range from a building not meeting its energy use target to a building causing people to become ill from exposure to various chemicals or biological organisms. These failures cost society considerable amounts of money each year and many of these failures are preventable already during the design stage of the building process. This thesis looks at some of the costs associated with building failures due to moisture problems and explores the reasons why these failures are persistent in the building industry. This is done by looking at the role of computer based tools, interviewing moisture consultants, analysing how they operate and what limitations both they, and the tools they use, have. One result in this thesis shows that a considerable amount of money is spent on repairing moisture damages in buildings. Another result is that the consultants who can prevent these problems are not able to accumulate experience due to a poor management system which only focuses on profit and not the development of the consultants. Building physics tools are not used due to high costs, usability issues or inadequate information regarding the use of the tool. A system of operation is proposed in the thesis which can make experience meaningful to consultants. The tools themselves are limited by deficiencies in moisture transport theory which cannot take into account non-isothermal moisture transport or variable thermal properties. Some of the problems with non-isothermal moisture models are discussed and new ways to improve such models are proposed in this thesis.