The Effect of Fire Retardant Composition on Burning Path and Determination of Thermal Resistance of Sawdust for Building Insulation

Increasing cost of energy requires application of thermal insulation for building. Sawdust filled with CaCO3 fire retardant is potential to be applied for building insulation to conserve heat energy across the insulation so that to reduce electrical energy consumption for the building. An apparatus for measuring burning path of sawdust filled with CaCO3 fire retardant has been constructed. Heat flux meter was also constructed to measure thermal conductivity and thermal resistance of the sawdust insulation. The composition of CaCO3 fire retardant in sawdust mixture used in the experiment ranged from 5 % to 30 % and 100 % sawdust was used as control. The burning path and burning time were measured for each composition of CaCO3 and for the control, as well as, burning velocity was determined. Thermal data of the sawdust insulation was determined for density of 43.25 kg/m3 and 64.88 kg/m3 with thickness of the insulation from 2 cm to 8 cm. The burning path, as well as, burning time decreased as the composition of CaCO3 fire retardant increased with the smallest one of 1.25 cm and 5 minutes achieved for CaCO3 30 %.  The lowest burning velocity was achieved at CaCO3 30 %. Thermal conductivity and thermal resistance increased with the increasing of the thickness of the sawdust insulation. The highest thermal conductivity of 0.553 W/mK and the highest thermal resistance of 0.145 m2K/W achieved at 8 cm thickness of the insulation and density of 43.25 kg/m3, while at density of 64.875 kg/m3, the highest thermal conductivity was 0.398 W/mK and the highest thermal resistance of 0.201m2K/W.