Whole building HAM transfer

The hygrothermal behaviour of the building envelope has a very significant effect on the overall performance of buildings. However, in most applications, building envelope designers attempt to predict the hygrothermal performance of an individual building envelope, for example a wall, roof or basement by uncoupling the system, not only from the building’s multi-zone airflows but the interactions of the other envelope components to both the exterior and interior environments. The stand-alone analysis of specific envelope components is important in understanding the influences of various controlling elements in terms of their effect on the hygrothermal performance of the envelope, but provides limited performance information on the overall heat, air and moisture transfer of a building. A more advanced building performance evaluation approach requires the direct coupling of all building envelope systems with the interior environment (multi-zone airflow), mechanical systems and the exterior environmental loads.

Simultaneous heat, air and moisture transfer between building envelopes and indoor air is complicated and expensive to measure in the laboratory or field experiments. Numerical modelling becomes an attractive alternative for understanding and extrapolating experimental results, as well extending and optimizing building performance. During the past ten years, a number of computer codes/models have been developed and validated worldwide for analysis the hygrothermal transport phenomena through a building enclosure exposed to the exterior environment3,10. However, very few models incorporate the critical hygrothermal interactions between the building envelope and multi-zone airflow. The proposed research aims at developing a model for predicting coupled multi-zone hygrothermal–airflow transfer in air-conditioned buildings. The whole building heat, moisture and airflow transfer model calculates the interactions between multi-zone airflow and primary hygrothermal effects in buildings (see above Figure ). The model will be validated by experimental measurements or published test suites. 

 

Relevant papers:

https://www.staff.dtu.dk/menqin/research/advanced-building-physics-research/whole-building-ham-transfer
5 OCTOBER 2022