Moisture flow modelling within the ESP-r integrated building performance simulation system

Moisture plays a central role in the provision of healthy buildings, both in relation to indoor humidity levels, which impacts on air quality and thermal comfort, and in relation to interstitial/surface condensation leading to fabric deterioration and mould growth, which impacts on performance and occupant well-being. Integrated building performance simulation (IBPS) provides a means to ensure that due consideration is given to these aspects at the design stage as designers attempt to deploy new approaches to energy demand reduction and sustainable supply. This paper describes how building space and construction moisture flow is modelled within the ESP-r system in a manner that is appropriately coupled to other domain models representing the heat, power, air and light flows within building/plant systems of arbitrary complexity (but with the focus here only on those domains that impact directly on moisture flow). The purpose of the paper is to describe the role of moisture flow modelling within IBPS, the barriers that are likely to be encountered in practice and future development needs. The application of the integrated approach is summarized for the case of mould growth alleviation and the deployment of passive methods for moisture control.