Vindar med begränsad ventilation - Fukttekniska undersökningar

Tougher fire requirements and the desire to make simpler designs have enabled construction companies to go from the traditional well-ventilated attic to attic with limited ventilation. Theoretically limited ventilated winds should perform well. The problem you see if there is construction moisture or external moisture sources. Problems may occur when the small ventilation is not able to remove moisture to the extent necessary. Heavier constructions usually have a large amount of construction moisture in the attic floor, which can be transferred to the attic space. Heavier structures with limited ventilated attics have not been studied previously. AK Consulting was commissioned to evaluate five attics to a construction company erected in 2014 and 2015. Former investigations showed that there was a risk initially with respect to the excess moisture from building moisture. This study was carried out with theoretical calculations on a model of an existing attic with moisture problems. The present thesis was commissioned by AK Consulting. It evaluated the data and reports from the five attics and assesses them with the help of WUFI BIO and made theoretical calculations in WUFI. The study shows that attics with limited ventilations work well initially and that the ventilation of the attic does not lead to drier attics. Longer measurement periods are required in order to see how the wind works in the long term and in different outdoor climates. It is difficult to determine the effect of initial dehumidification of the winds. The attics have little or no excess moisture over the measurement period. The recommendations are to dehumidify attics initially until further studies have been done on similar structures. It is also important to continue monitoring the attics in this study to follow up how they work in the long term and during years with different climatic conditions