Hygro-thermal response of a ventilated attic to the future climate load in Sweden

Paper i proceeding, 2009

Universal in most climate change scenarios for the 21st century is the increase of the global mean temperature. By the end of the century the increase may be 1-6 oC depending on the chosen emission scenario. Climate scenarios for Sweden point to a warmer and more humid climate in future. It can be expected that the building parts, which are already susceptible for moisture load, will degrade more in future. In Sweden, a ventilated cold attic is a typical representative of a moisture-sensitive construction part. This paper investigates numerically the hygro-thermal response of a typical ventilated attic to a possible future climate load in Sweden. The hygro-thermal conditions in the attic are assessed by a mould growth index (MGI). The results showed the increment of MGI in future for all test cases. The analysis showed that the orientation of a roof and the moisture load to the attic from a dwelling underneath are the influencing parameters on MGI. Since the latter is governed mainly by the ventilation system in a house, the type of the ventilation system is important design parameter for the prevention of future moisture problems in ventilated attics.