In low energy buildings, the proper design of the building envelope assembly is critical. A conventional building uses massive amounts of mechanical energy to heat and cool, thus driving moisture into or out of the building assembly. A passive building uses a much more subtle method of heating and cooling which makes the proper long term performance of the building assembly critical to long term performance.
Utilizing the program WUFI, we offer cutting edge analysis of the hygric behavior of building assemblies.
WUFI-ORNL/IBP - What's that?
WUFI - Oak Ridge National Laboratory (ORNL)/Fraunhofer Institute for Building Physics (IBP) is a menudriven PC program which allows realistic calculation of the transient coupled one-dimensional heat and moisture transport in multi-layer building components exposed to natural weather. It is based on the newest findings regarding vapor diffusion and liquid transport in building materials and has been validated by detailed comparison with measurements obtained in the laboratory and on outdoor testing fields.
Besides the thermal properties of a building component and their impact on heating losses, its hygric behavior has to be considered, too. Permanently increased moisture content in the component may result in moisture damages. Elevated surface moisture levels in living rooms can lead to hygienic problems and health risks due to mould growth.
In addition, thermal and hygric behavior of a building component are closely interrelated as well as an increased moisture content favors heat losses. The thermal situation affects moisture transport. Therefore, both have to be investigated together in their mutual interdependence; the research field of hygrothermics is dealing with these problems.