One solution for reducing buildings’ energy consumption and carbon emissions is using highly insulated structures. In doing so, we also need to ensure a healthy indoor environment by preventing humidity and condensation.
Traditional insulation materials, often petrochemical-based, are one of the major contributors to the construction industry’s carbon emissions. Therefore, shifting to natural-based products with low embodied carbon is necessary. Wood fibre insulation (WFI) products, if produced efficiently, are a good, eco-friendly option. In addition, their use helps to balance the indoor air humidity. However, the UK has no domestic production, and the purpose of this research is to determine the compatibility of homegrown resources with the production process, and which species or mix offer a potential solution. This way, we can reduce imports, support local jobs, and create a more sustainable industry.
The effectiveness of WFI in reducing heat transfer depends on the material’s physical properties, such as fibre density and size. Softwood, the main material utilised in WFI, is characterized by strong fibre network and longer fibres, which are valid characteristics to prevent heat transfer. However, due to the increasing demand for softwood in biomass production and current forest management trends, the use of hardwoods in wood fibre-based materials is expected to rise significantly. Hence, through a Forestry Commission-funded project, we explored the use of UK hardwood fibres, to understand how they can be blended to achieve high-quality thermal insulation that not only meets current performance values but aspires to improve them.
We first developed a decision analysis method to select suitable hardwood species based on availability, density, fibre length, and fibre share. Our research identified alder, beech, birch, poplar, and sycamore as suitable options. With a digital microscope, we then analysed the UK hardwoods and softwood fibres, to evaluate their length, and we determined also their bulk density. Finally, we compared our findings with past research to identify the best blends of UK wood for insulation.
Our study provides valuable insights into the use of hardwoods for insulation, addressing a gap in European research where few studies have been conducted, and results have been mixed. We will also share the key highlights and lessons learned from our research. This project is part of a portfolio of studies into how UK-grown wood can be used for added-value products that promote sustainable practices in the construction industry. A key objective of this innovation is to lock carbon into the built environment whilst improving its operational efficiency.
Keywords: wood fibre, natural insulation, hardwood
Authors
Paola Seminara
The University of Edinburgh, United Kingdom
Julio Bros-Williamson
Université de Lorraine,LERMAB, France
Andrew Livingstone
Edinburgh Napier University, United Kingdom
Robert Hairstans
New Model Institute for Technology and Engineering, United Kingdom
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