The aim of this study is to validate different analytical relations used in hygrothermal simulations for the material properties. Therefore, a valida tion experiment on four types of flat roofs has been set up at the laboratory. All rele vant material properties of the individual material layers were determined before hand. During the experiment, temperatures, heat fluxes and moisture contents were measured. The measured data were then compared with numerical simulation results. By repeating the simulations with different expressions for the vapour per meability and for the sorption isotherm, the influence of approximate analytic rela tionships was investigated.
ASTM Designation E96-80, "Standard Test Method for Water Vapour Transmission of Materials."
2.
ASTM Designation C518-91, " Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus."
3.
Bear,J. and Bachmat,Y. , "Introduction to Modelling of Transport Phenomena in Porous Media,"Kluwer Academic Publishers, Dordrecht , 1975.
4.
Depraetere, W. and Lambrecht, B., "Validatie van Modellen voor Gekoppeld Warmte- en Vochttransport," (Validation of models for coupled heat and moisture transfer, in Dutch), Masters Thesis, K.U. Leuven, Belgium, 1996.
5.
DIN 52 615, "Bestimmung der Wasserdampfdurchlassigkeit von Bau- und Dammstoffen," 1973.
6.
Geving, S., "Moisture Design of Building Constructions, Hygrothermal Analysis Using Simulation Models," Ph.D. Thesis, Department of Building and Construction Engineering, The Norwegian University of Science and Technology , Norway, 1997.
7.
Glaser, H., "Temperatur und Dampfdruckverlauf in einer homogen Wand bei Feuchteaussscheiding,"Kaltetechnik, pp. 174-181, 1958.
8.
Hansen, F.P., "Coupled Moisture and Heat Transport in Cross Sections of Structures,"Beton og Konstruktionsinstituttet (BKI), Denmark, 1985.
9.
Hens, H., "International Energy Agency. Annex 24: Heat, Air and Moisture Transfer in Insulated Envelope Parts. Final report. Task 1: Modelling, Vol. 1,"Laboratorium Bouwfysica Departement Burgerlijke Bouwkunde, K.U.Leuven, Belgium, 1996.
10.
Janssens, A., "Drying of a Heavy Flat Roof: A Comparison between Full and Simplified Modelling," Report T1-B-94/06, IEA Annex 24, HAMTIE, 1994.
11.
Kiessl, K., "Kapillarer und Dampfformiger Feuchtetransport in Mehr-schichtigen Bauteilen," Ph.D. Thesis, Universitat-GesamthochschuleEssen, 1983.
12.
Kumaran, M.K., "International Energy Agency. Annex 24. Heat, Air and Moisture Transfer in Insulated Envelope Parts. Final report. Task 3: Material Properties," Laboratorium Bouwfysica Departement Burgelijke Bouwkunde, K.U.Leuven, Belgium, 1996.
13.
Künzel, H.M., "Simultaneous Heat and Moisture Transport in Building Components. One- and Two-dimensional Calculation Using Simple Parameters," Ph.D. Thesis, Umversitat Stuttgart, IRB Verlag, Germany, 1995.
14.
Lecompte, J., "De Invloed van Natuurlijke Convectie op de Thermische Kwaliteit van Geisoleerde Spouwconstructies." (The Influence of Natural Convection on the Thermal Quality of Insulated Cavity Constructions, in Dutch), Ph.D. Thesis, Laboratorium Bouwfysica, Departement Burgelijke Bouwkunde, K.U.Leuven, Belgium, 1989.
15.
Luikov, A.V., Heat and Mass Transfer in Capillary Porous Bodies, Pergamon Press, 1966.
16.
Matsumoto, M., "Simultaneous Heat and Moisture Transfer and Moisture Accumulation in Buildings," Ph.D. Thesis, Kyoto University, Kyoto, Japan, 1978.
17.
NBN B 05-201, "Resistance of Materials to Freezing—Water Absorption by Capillarity," 1976.
18.
NBN B 24-213, "Masonry Units Testmg—Water Absorption under Vacuum," 1976.
19.
Ojanen, T., "Evaluation of Simplified Modelling. Hygrothermal Performance of Lightweight Flat Roof. Sensitivity Analysis Using Programme TCCC2D," Report T1-SF-94/03, IEA Annex 24, HAMTIE, 1994.
20.
Philip, J.R. and de Vries, D.A., "Moisture Movement in Porous Materials under Temperature Gradients,"Transactions of the American Geophysical Union, Vol. 38, pp. 222-232, 1957.
21.
Pedersen, C.R., "Combined Heat and Moisture Transfer in Building Constructions," Ph.D. Thesis, Thermal Insulation Laboratory, Techmcal University of Denmark , Denmark, 1990.
22.
Roels, S., Depraetere, W. and Hens, H., "The Influence of Approximative Analytic Relations for Material Properties on Numerical Simulations of Combined Heat and Moisture Transfer," In Proceedings of CIB W40—Meeting on Heat and Moisture Transfer in Buildings, Kyoto, Japan, 1997, CIB Proceedings, Publications 213, pp. 75-93, CIB Rotterdam, 1998.
23.
Salonvaara,M. andKaragiozis, A., "Hygrothermal Behaviour of a Brick Cavity Wall. Part A: Simplified Material Properties," Report T3-CA-94/01, IEA Annex 24, HAMTIE, 1994 .
24.
Withaker, S., "Simultaneous Heat, Mass and Momentum Transfer in Porous Media: A Theory of Drying Porous Media,"Adv in Heat Transfer, pp.119-203, 1977.
25.
Zarr, R.R., Burch, D.M. and Fanney, A.H., "Heat and Moisture Transfer in Wood-Based Wall Construction: Measured versus Predicted,"NIST Building Science Series 173, U.S. Government Printing Office, Washington , 1995.
26.
Zienkiewicz, O.C. and Taylor, R.L., The Finite Element Method Fourth Edition, McGraw-Hill , London, 1994.
