CATEGORIES2021 Symposium Abstracts Conference Papers
Australia’s current climate datasets were developed for thermal (heating and cooling) building performance simulations during a period where government policy pushed for a reduction of greenhouse gases. However, modern energy efficient buildings need to include hygrothermal envelope design. Significant concern has been raised about the appropriateness of the approved building energy efficiency climate data sets for hygrothermal analysis. Additionally, these datasets do not include rain data; , and Wind Driven Rain (WDR) is a critical input for hygrothermal analysis (Salonvaara and Karagiozis 1998). This has created a scenarios where a hygrothermal simulation practitioner is left with a choice; to cobble together a dataset by adding precipitation to the existing climate data or to use one of an assortment of climate datasets available online or through private corporations. Predictably, with this muddy climate data situation, simulation outcomes vary from practitioner to practitioner.
WUFI Pro 6.5 is an internationally recognised transient hygrothermal simulation application that meets current regulatory recommendations. The software will be used to simulate hygrothermal behaviour and moisture content in interstitial spaces.
Melbourne Tullamarine was chosen due to its proximity to significant urban development and for its rich precipitation data owing to its proximity to an international airport. The wall assembly explored in the paper is precast concrete, which is typically used in Class 2 apartment building construction. To test the effect of different climate data inputs, two RMY climate files will used for hygrothermal and bio-hygrothermal simulations; namely, RMY with no alterations, and RMY with added rain data.
The results show a similarity in moisture content that was not expected.
Climate data is concatenated from a period of historical weather observations. The current Representative Meteorological Year (RMY) is produced following the procedure for the generation of the Typical Meteorological Year (TMY2) using the Finkelstein–Schafer statistic on weighting factor on data fields (Lee n.d.) from a period of record between 1970 – 2005. The weighting factors for RMY were chosen for thermal simulations, and as such, the dataset is thermally selected with an emphasis on temperature and solar radiation and do not include rain data.
Are these thermally selected climate datasets producing realistic hygrothermal simulation outcomes?
Future research will scrutinise how other jurisdictions constructed their climate files for hygrothermal analysis and formulate experiments to test their methodology using Australian climate and weather data.
Lee, Trevor. n.d. “Australian Climate Data Bank – Element Weightings.” Accessed October 19, 2021. http://www.exemplary.com.au/download/Australian%20Climate%20Data%20Bank%20-%20Element%20Weightings%20-%202019-05-11.pdf.
Salonvaara, Mikael, and Achilles N Karagiozis. 1998. “The Influence of Waterproofing Coating on the Hygrothermal Performance of a Brick Façade Wall System.” STP1314. American Society for Testing and Materials (ASTM). https://www.astm.org/DIGITAL_LIBRARY/STP/PAGES/STP12113S.htm.