Physical properties of insulation materials based on straw and flax boon

Abstract

Performance evaluation of environmentally friendly thermal insulation materials based on crushed straw and flax boon was determined by studying the physical parameters of thermal insulation in a climatic chamber and full-scale tests in buildings. In the climatic chamber at an air temperature of –20 °С, depending on the insulation moisture content, the thermal conductivity of the flax boon and straw slabs is 0.058 - 0.072 W/(m·°С), which is 27 - 31% lower than that of straw slabs equal to 0.08 - 0.105 W/(m·°C). With a relative air humidity of 50 - 95%, the moisture content of the flax boon and straw slabs varies within the range of 14 - 18.1% or less by 24% of the values of the crushed straw insulation. Under operating conditions, the thermal conductivity of the attic floor structure with flax boon and straw slabs corresponds to 0.07 W/(m·°C) at an air temperature of –20°C and is 22% less than the similar indicator of flooring with straw slabs equal to 0.09 W/(m·°C). A lower thermal conductivity of the floor structure with the use of flax boon and straw slabs provides an increase in temperature amplitude by 5 - 5.8 °C compared with the use of straw slabs. The results of studies in the climatic chamber and full-scale tests have confirmed the most effective operation of the flax boon and straw slabs as a thermal insulation material, which reduces energy consumption and, consequently, reduces financial costs for heating buildings.