Experimental Investigation of Building Thermal Insulation from Agricultural By-products

The thermo-physical properties of environmentally friendly biodegradable agricultural by-products, oil palm, coconut and sugarcane fiber, were investigated for use as potential building thermal insulation. Thermal conductivity measurements were conducted on 51 mm thick, 254 mm square test specimens in accordance with ASTM C518 where the apparent thermal conductivity, λ, was measured under steady-state one-dimensional test conditions with heat flow upwards. The test apparatus provided λ measurements with ±0.2% repeatability and ±0.5% reproducibility within the range 0.005 W/m.K to 0.35 W/m.K. For all three materials, experimental data at various mean test temperatures show the thermal conductivity variation with density followed the characteristic hooked shape associated with loose-fill fibrous insulation. Test results indicated that sugarcane fiber with the lowest solid fiber density of 686 kg/m3 exhibited the lowest apparent thermal conductivity of 0.04610 W/m.K and a trend of increase in solid fiber density of the material reflected an increase in the minimum λ of the fibrous batt. The minimum λ for the materials ranged between 0.04160 W/m.K to 0.05784 W/m.K over the mean temperature ranges 15.6°C to 32°C. These λ values are within the range 0.02 W/m.K to 0.06W/m.K which is normally used for thermal building insulation.