A preliminary analysis of subfloor ventilation data – bridging the gap between theory and experiment
Authors: Sequeira, Sabrina ; Fay, Roger; Sargison, Jane ; Soriano, Florence
Building simulation programs are key tools in the design of thermally stable housing. It is therefore essential that these programs are accurate. AccuRate, the building simulation program developed by CSIRO, consists of a set of physics-based numerical models. Recent research seeking to validate the AccuRate program against experimental data suggests that its subfloor model may be inaccurate. This study investigates that subfloor model, specifically the quantification of the subfloor ventilation.
This paper introduces one of the University of Tasmania’s thermal performance research test cells. The test site is analysed in regards to local wind obstructions using computational fluid dynamics and the test cell is found to be suitable for ventilation testing. New subfloor ventilation data gathered from a tracer gas decay test is presented and shown to generally match the theoretical prediction from AccuRate. The data is further explored to find nuances resulting from obstructions from surrounding buildings. No nuances are found. The data is also benchmarked against several other subfloor ventilation studies from Australia and the U.K.
Due to the low number of data points and the known variability in the data, this study is considered preliminary only. More experimental data would be needed to validate the AccuRate subfloor ventilation model.