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The erection of new buildings, the renovation and preservation of building structures and monuments requires the quantification of the temperature, moisture, salt and pollution distribution in porous materials. The thermophysical modeling leads to a coupled nonlinear differential equation system. The temperature T and the capillary pressure pc will be used as driving potentials in this transport system. The air and salt transport and the crystallization and ice forming have been neglected in this paper although this processes have been formulated, too. In order to solve the transport equation system with modern numerical methods the material functions thermal conductivity λ(w( pc),T ), capillary conductivity K(w( p c),T ) and vapor conductivity δ(w( pc), T ) and the moisture retention function w( pc,T ) are necessary. This paper will be focused on the determination of w( pc) and K(w( pc)) in the isothermic case. The results will be compared with measurement results of the capillary active insulation material ``calciumsilicate''.

Die vorliegende Arbeit leistet einen Beitrag zur gekoppelten aero‐hygrothermischen Bauteilsimulation für Strukturen mit Hohlräumen. Den Schwerpunkt bildet dabei die Entwicklung eines CaFD‐Modells (Cavity Fluid Dynamics) und Computercodes, welche auf der Lösung der Navier‐Stokes‐Gleichungen für laminare Strömungen inkompressibler reibungsbehafteter Fluide basieren. Mit der Definition einer Softwareschnittstelle gelingt es, den zunächst eigenständig ausführbaren Strömungslöser CaFD‐Tool in Form einer dynamischen Bibliothek in den Quellcode der am Institut für Bauklimatik der Technischen Universität Dresden entwickelten Software DELPHIN 4 einzubinden. Mit der Formulierung eines vereinfachten Mehr‐Zonen‐Modells ist es möglich, die bei einem durchströmten Hohlraum oder Spalt auftretende Überlagerung von natürlicher und erzwungener Konvektion zu simulieren. Außerdem können die Feuchtefelder, verursacht durch Kondensationserscheinungen der eindringenden feucht‐warmen Raumluft im Hohlraum und im angrenzenden Baustoff quantifiziert werden. Neben der exakten energetischen Beurteilung der Bauteile lassen sich Möglichkeiten zur Vermeidung von Feuchteschäden aufzeigen.

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The component simulation program DELPHIN, which is usually used for component simulation including coupled heat and moisture transport, has also implemented a pipe model that is currently not documented. This model can be used for various purposes, including the modelling of heat input/output by surface heating/cooling systems in building structures. Furthermore, it allows an estimation of energy gains and storage potentials by ground collectors by considering the ground including the collector pipe, etc. The same pipe model is implemented isotropically in NANDRAD in order to model and to consider underfloor heating systems in the thermal building simulation. The implementation of this pipe model for DELPHIN (component simulation program) and NANDRAD (building simulation program) is described, investigated and documented in this paper for underfloor heating and cooling systems. Especially the heat transfer between pipe wall and fluid is discussed in more detail. Therefore, the parameterization and the flaw between the anisotropic tube model (two-dimensional heat radiation inside the component) in Delphin and the isotropic model (heat input to a component layer) in NANDRAD are being examined.