Experimental and numerical investigations of thermal performance of a Hemp Lime external building insulation

• Published in: Building and environment 2018-03, Vol.131, p.140-153
• Main Authors: Costantine, Georges, Maalouf, Chadi, Moussa, Tala, Polidori, Guillaume
• Format: Article
• Language: English
• Subjects: Air temperature; Building envelopes; Champagne; Computer simulation; Concrete; Concrete construction; Construction; Engineering Sciences; Experimental measurements; Heat conductivity; Heat flux; Heat transfer; Hemp; Hemp-concrete; Humidity; Indoor environments; Insulation; Monitoring; Numerical validation; Relative humidity; SPARK; Sustainable materials; Weather
• ISSN: 0360-1323; 1873-684X
• DOI: 10.1016/j.buildenv.2017.12.037

Hemp-concrete is a green material which has become nowadays highly recommended in the construction field. It finds applications as internal or external thermal insulator in wooden frame walls. At wall scale, studies proved that using Hemp-concrete in building envelope can improve indoor hygrothermal comfort. However, at building scale, hemp-concrete is scarcely studied. In that context, a French building in Grand-Est region, Champagne-Ardennes, employing hemp-concrete as external insulator is selected and studied. An apartment is monitored for several months. Indoor temperatures, relative humidities, thermal heat flux as well as external weather conditions are measured using sensors installed inside the apartment and a weather station at the building roof. Measurements underline the hemp-concrete ability to dampen external weather conditions by showing good results for both indoor temperature and relative humidity. Experimental approach is then coupled with a numerical validation at the wall and room scales using SPARK simulation tool. Investigations are conducted on thermal heat flux through the wall, indoor office air temperature, and relative humidity. Results show a good agreement between numerical values and experimental measurements. •Indoor temperature and relative humidity of a building employing hemp-concrete as external insulation is investigated.•Thermal heat flux through a wall of the studied apartment is measured and coupled to a numerical validation at wall scale.•Indoor air temperature and relative humidity in the office coupled to a numerical study at room scale.•A parametric study shows that materials properties have a great influence on numerical heat flux at wall scale.•Simulation parameters as indoor convective heat transfer coefficients and occupancy scenario are important keys for results optimization at office scale.