Several studies have reported poor indoor air quality (IAQ) in day care centers (DCCs), and other studies have shown that children attending them have an increased risk of respiratory and gastrointestinal infections. The aim of this study was to investigate whether there is an association between ventilation in DCCs and sick leave among nursery children. Data on child sick leave within an 11-week period were obtained for 635 children attending 20 DCCs. Ventilation measurements included three proxies of ventilation: air exchange rate (ACR) measured with the decay method, ACR measured by the perfluorocarbon tracer gas (PFT) method, and CO2 concentration measured over a 1-week period. All but two DCCs had balanced mechanical ventilation system, which could explain the low CO2 levels measured. The mean concentration of CO2 was 643 ppm, exceeding 1000 ppm in only one DCC. A statistically significant inverse relationship between the number of sick days and ACR measured with the decay method was found for crude and adjusted analysis, with a 12% decrease in number of sick days per hour increase in ACR measured with the decay method. This study suggests a relationship between sick leave among nursery children and ventilation in DCCs, as measured with the decay method.

This paper presents at project for renovation of a large residential area, where focus is on moisture safe internal insulation measures and the energy saving potential. Parts of two three-story houses were renovated with different combination of capillary active insulation measures including mechanical ventilation with heat recovery in one house. For two years, energy use for heating was measured as well as temperature and relative humidity in the internal insulation, indoors and outside. The insulation was dismantled in two apartments after two years, to test for mold growth at the original wall surface. Furthermore, the indoor climate and energy use for heating was measured in nine reference apartments. The inspection and mold measurements after the removal of the insulation material did not show signs of mold growth. Apparently, the used insulation material can be used in these specific cases without risk of mold growth. However, the relative humidity behind the insulation was measured up to 90% in the first winter and decreased to 70% relative humidity in the next winter. There was a good agreement between measured and calculated energy savings for heating; and up to 24% savings was documented for the house with more far-reaching measures.

In the debate on whether or not heritage buildings should be included in work to mitigate climate change impacts, it is important to assess the impact of these buildings. Therefore the results of an extensive energy upgrading of a listed complex was studied. Climate change and measures to mitigate its effects have been a global priority for more than a decade. Efforts to mitigate climate change have focused on reducing greenhouse gas emissions, especially CO. As a consequence, there is an increased interest in reducing the energy consumption and increase the indoor climate standard of many existing, older and heritage buildings. However, heritage buildings possess heritage values that need to be protected while on the other hand the buildings need to remain part of the attractive building stock, as many of these buildings will otherwise deteriorate. Based on an example, this paper identifies feasible energy-upgrading measures for implementation including measures to provide an acceptable indoor climate. The energy savings as well as the reduction of CO emissions are calculated. Furthermore, it is discussed how measures can affect the durability of a heritage building, as measures may create a far more vulnerable building and change its robustness to withstand moisture and user behaviour.