Danish and Brazilian Modeling of Whole-Building Hygrothermal Performance

The humidity of rooms and moisture conditions of materials in the enclosure of buildings depend much on each other because of the moisture exchange that takes place over the interior surfaces. These moisture influences also depend strongly on the thermal conditions of indoor spaces and enclosure elements of buildings.

In turn, the moisture and humidity conditions have significant impact on how buildings are operated. In hot-humid climates it may be desirable to keep the ventilation rates low in order to avoid too high indoor humidity, while in cold climates ventilation can be used to keep the humidity low and thus reduce the risk of moisture damage in the building enclosure.

In either case the indoor humidity has a direct or indirect impact on the energy performance of the HVAC system of a building. To analyze this situation, one could benefit from some recent developments in integrated computational analysis of the hygrothermal performance of whole buildings. Such developments have led to new hygrothermal models for whole buildings.

The paper gives examples of two such recent developments and will illustrate some calculation results that can be obtained. Finally the paper will mention some further developments and international collaboration on the subject.