Hygrothermal performance of building components and building elements - Assessment of moisture transfer by numerical simulation
prEN 15026:2004
2004 91.120.30
prEN 15026:2004, (2004), "Hygrothermal performance of building components and building elements - Assessment of moisture transfer by numerical simulation", 91.120.30.
Abstract:
This standard specifies a method for calculating the non steady transfer of heat and moisture through building structures. The necessary equations are defined and a benchmark example given. The hygrothermal simulation models covered by this standard take account of the following storage and onedimensional transport phenomena: - heat storage in dry building materials and absorbed water; -heat transport by moisture-dependent thermal conduction; - heat transfer by vapour diffusion and air convection, including phase changes; - moisture storage by vapour absorption and capillary forces; - moisture transport by vapour diffusion and air convection; -moisture transport by liquid transport (surface diffusion and capillary flow); The models described in this standard account for the following climatic variables: - internal and external temperature; -internal and external humidity; - solar and long wave radiation; - precipitation (normal and driving rain); - wind speed and direction; - air pressure differences. The hygrothermal models described in this standard shall not be applied in cases where: - convection takes place in a three-dimensional manner through holes and cracks; - two-dimensional effects play an important part (e.g. rising damp, conditions around thermal bridges, effect of gravitational forces); - hydraulic, osmotic, electrophoretic forces are present; - daily mean temperatures exceed 50 ˇăC or in cases of fire; - the effects of ice formation have to be assessed.