Thermal Properties of Hemp Shives Used as Insulation Material in Construction Industry

Abstract

The article presents the results of studies concerning raw hemp shives obtained from the Polish crop of industrial hemp as a loose-fill thermal insulation material. The study focuses mainly on the measurements of the pore size distribution, thermal conductivity and air permeability of material. An increase in the value of the thermal conductivity coefficient (0.049–0.052 W/(m·K)) was demonstrated with an increase in the bulk density. The porosity of the individual pieces of shives is 78.7% and the predominant number of pores is in the diameter range of 0.9–3 µm. The paper also presents an example of the use of the tested material as thermal insulation of the wooden frame wall. The heat flow analysis was performed in various wall variants (insulation thickness: 100, 200 and 300 mm and pressure difference 0, 5, 10 and 15 Pa). A clear influence of the variables on the temperature distribution was observed.