Relative Humidity, RH (%), a Problem or Not in Swedish Buildings

In 1972, the oil producing countries implemented an oil embargo on a number of states, including Sweden. During this period, oil was an important raw material for Sweden. The oil accounted for nearly 40% of Sweden’s total energy supply and was an extremely important source of heating for the Swedish building stock. Subsequently, restrictions from Swedish authorities have been introduced into how energy can be used. The purpose of these restrictions is to reduce energy consumption and a part of this is that new requirements have been introduced on how buildings should be designed. The changes have had negative consequences as people, who live in these types of buildings, claim that they suffer from health problems, which are referred to as “building related illness”. The purpose of this project is to examine how the structural changes regarding air exchange and windows carried out after the oil embargo in 1972, have affected the climate and environment in Swedish buildings. The aim is to investigate whether there are links between these changes and assertions about building-related illness. From an energy point of view, windows are a delicate building component and the project includes studying the effect of using an external roller shutter. Furthermore, the project aims to investigate how the environment and climate in Swedish buildings are experienced at the user level and how authorities assess the scope and effect of the measures they have implemented. The results show that unhealthily low levels of the relative humidity generally prevail in the Swedish housing stock and that the changes in the construction carried out after the oil embargo in 1972, regarding air exchange systems and window designs, reinforce the problem. With regard to various design alternatives, it is necessary in Sweden to consider the prevailing climate and environmental conditions and that the energy efficiency of the buildings is good.