ABSTRACT

Building envelope designers and architects provide expert advice during the selection of building envelope systems. Until recently, a limited hygrothermal engineering analysis was performed to determine performance of a selected wall system other than review the details of wall systems and subsystems. Infrequently, a glaser or dew point method analysis may have also been performed, but this kind of analysis is only steady state in nature and ignores the hygroscopic effects, such as nonlinear dependenc ies of hygroscopic material properties, moisture storage, freeze-thawing mechanisms, liquid transport, latent heat, and transient nature of moisture loads at the boundaries. The main reason for not performing a thorough moisture engineering analysis was the lack of an easy-to-use hygrothermal model that integrated the physics and that was accompanied by a material property database and a set of realistic hygrothermal environmental loads for both the interior and exterior of the envelope. Recently, the increasing demand for better performing calculation methods to assess the moisture behavior of building components prompted an international collaboration between the Oak Ridge National Laboratory (USA) and the Fraunhofer Institute in Bauphysics (Germany) to develop a hygrothermal design tool named WUFI-ORNL/IBP. This hygrothermal design model can assess the response of building envelope systems in terms of heat and moisture loads and can also provide a very useful and fair method for evaluating and optimizing building envelope designs. This state-of-the-art model is discussed in detail in this paper and is also available in North America free of charge at www.ornl.gov/btc/ moisture.

• HAM: computer models

1. A North American research approach to moisture design by modeling
2. Advanced hygrothermal modeling of building materials using MOISTURE-EXPERT 1.0
3. Advanced hygrothermal models and design models
4. An educational hygrothermal model: WUFI-ORNL/IBP
5. Applied moisture engineering
6. Barrier EIFS clad walls: Results from a moisture engineering study
7. Boundary element analysis of uncoupled quasi-static hygrothermoelasticity for two-dimensional composite walls
8. Building enclosure hygrothermal performance study phase I
9. Drying capabilities of wood frame walls with wood siding
10. EIFS hygrothermal performance due to initial construction moisture as a function of air leakage, interior cavity insulation, and climate conditions
11. Hygrothermal system-performance of a whole building
12. Importance of moisture control in building performance
13. Influence of material properties on the hygrothermal performance of a high-rise residential wall
14. Integrated approaches for moisture analysis
15. Integrated hygrothermal performance of building envelopes and systems
16. Measurements and two-dimensional computer simulations of the hygrothermal performance of a wood frame wall
17. Moisture transport in building envelopes using an approximate factorization solution method
18. Position paper on material characterization and HAM model benchmarking
19. Simulation of indoor temperature and humidity conditions including hygrothermal interactions with the building envelope
20. Wind-driven rain distributions on two buildings  

1. Calculation of heat and moisture transfer in exposed building components
2. Combined effect of temperature and humidity of the detoriation process of insulation materials in ETICS
3. Flexible vapor control solves moisture problems of building assemblies - smart retarder to replace the conventional PE-film
4. Moisture buffering effects of interior linings made from wood or wood based products
5. Mold growth prediction by computational simulation
6. Simulation of indoor temperature and humidity conditions including hygrothermal interactions with the building envelope
7. Simultaneous heat and moisture transport in building components. one- and two-dimensional calculation using simple parameters
8. Two-dimensional transient heat and moisture simulations of rising damp with WUFI 2D
9. Uncertainty of hygrothermal calculations