Funds: Research Fund ETHZ

The investigation of heat and moisture transfer in building materials by the IEA project HAMTIE (heat, air and moisture transport in insulated envelopes) as well as our own work has demonstrated the thermodynamic, phenomenological approach to be very limited in its usefulness. The relevant material functions are very difficult to determine. Any further progress will require a microscopic model. The models developed up to now failed because of the very complicated geometry of the porous structures. Due to the large scale of porosity from nm to mm and its at least in a statistical sense present self-similarity, we hope to develop a better model approach by using fractal structures as a basis.

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