Paper Conference

Proceedings of Building Simulation 2017: 15th Conference of IBPSA


Identifying a Suitable Climate File for the Moisture Risk Assessment of Internally Insulated Walls Exposed to Solar-Driven Vapour Diffusion

Valentina Marincioni1, Hector Altamirano-Medina1
1Insitute for Environmental Design and Engineering, University College London, Central House, 14 Upper Woburn Place, WC1H 0NN, London, UK

Abstract: In the UK, 20% of the building stock is subject to solardriven vapour diffusion due to the un-rendered external surface of solid walls. Energy efficient interventions such as the installation of internal wall insulation can help to reduce greenhouse gases emissions and improve the thermal performance of those buildings. However, if the interventions are incorrectly designed, moisture accumulation may occur, which could be detrimental to the building and the health of its occupants. The moisturerelated risk of such interventions is usually evaluated using hygrothermal simulations, however some of the input data required for the evaluation are not always suitable for the purpose; in particular, this is the case for external climate data. The aim of this study is to identify a suitable climate file for the risk assessment of internally insulated walls affected by solar-driven vapour diffusion. This paper presents an evaluation of the commonly used typical and near-extreme reference climate files for moisture risk assessment. Hygrothermal simulations were carried out for both types of climate files and 19 years of measured data. Results indicate that the near-extreme files underrepresent the worst-case scenario and that the penetration of rainwater does not significantly affect the output of the hygrothermal simulations. A distribution of climate files was found to be more accurate and representative for the moisture risk assessment when considering solar-driven vapour diffusion.
Pages: 2123 - 2128