Natural Fibre Insulation in Rural Southern Chile

Thermal insulation is probably one of the most important elements in reducing the heating demands of residential accommodation in a cool temperate climate. However many insulating materials have a large environmental impact and high embodied energy. Research has shown that natural fibres can provide insulation with a lower impact especially when sourced locally. This paper presents a study of the natural fibres with insulating potential available in the micro-region of Araucania Andina in Chile’s 9th Region, a temperate region with long cold wet winters and short hot summers. An environmental impact matrix is used to select the materials with the lowest impact, which in turn are subjected to laboratory guarded hot box testing to determine their thermal conductivity. The final results will inform the design of a sustainable construction system for the micro-region. Materials evaluated include cellulose fibre from the forestry industry which is one of the principal sectors in the local economy; straw bales from wheat production, Chile’s main agricultural crop of which the region is the second largest national producer; sheep’s wool from the region and those further to the south; and two different local species of bamboo, colihue which currently has limited use for furniture and internal finishes and the highly invasive quila which requires constant clearing to reduce the threat of forest fires yet has no current commercial value. Results show that sheep’s wool provides the best insulation values, followed by straw bale and interesting that chipped quila bamboo could provide an economic natural insulation with low environmental impacts.