Modeling of conventional timber drying using alternative methods

Architects are increasingly specifying sustainable solid wood products within buildings. Many specify a high of uniform appearance. This contrasts with standard timber outdoor yard-based air-drying processes that can lead to non-uniform appearance. Timber discoloration that has resulted from the drying process leads to the discarding of a high-quality natural resource. the lower recovery rates significantly lower economic yields and increase reprocessing costs. The conventional rack based drying process is subject to multiple environmental factors that can cause this degradation.  Rack surveys can map and reveal the location and severity of timber defects resulting from the drying process, but in some cases it is difficult to understand the reason that certain defects happen under different drying conditions. Almost of those defects are the result of heat and moisture flows throughout the timber racks. Historically, computational fluid dynamics software has been used to simulate the drying processes. However, these tools only explore the flow of heat and not the significant changes in moisture that occurs in timber during the drying process. Recognising this deficiency, this research is exploring the alternative use of hygrothermal simulation software tools to view the flow of heat and moisture through racks of drying timber located in an outdoor environment. Traditionally, these tools have been used to inform envelope design of buildings. Liaising with software developers from Germany, this research is exploring the capability of two-dimensional hygrothermal simulation tools to mimic moisture affecting discoloration patterns during the timber drying process.