Study of hygrothermal behaviour of a hemp concrete building envelope under summer conditions in France

This paper presents some preliminary investigations about the transient hygrothermal behaviour of a hemp concrete envelope under summer conditions in France. The first part compares the thermophysical properties of hemp concrete to those of other materials used in construction. Then in order to investigate the material hygrothermal behaviour in a building envelope, a coupled heat and mass transfer model is implemented into the simulation environment SPARK and validated with experimental data available from the current literature. Simulations for a room made of hemp concrete are run under summer conditions for three French cities. Our results suggest that in South France the use of hemp concrete in buildings can lead to an indoor superheating for more than 70% of occupation period. These conditions can be improved significantly by using the combined effect of external solar shading, night ventilation technique and high energy storage capacity materials.