Impact of Solar Radiation on Hygrothermal Behavior of a Washing Fine Hemp Wall

The hygrothermal behavior of Washing Fines Hemp Composites was investigated experimentally and numerically at the wall scale for several French and Tunisian climates without considering solar gains nor rain. The stabilization phase leads to experimental and numerical thermal conductive resistance consistent with the theoretical one. The hygric resistance is consistent for simulation performed up to steady state. The profiles at different time during daily climate cycles show that two thirds of the thickness of the wall on the exterior side are active and sorption-desorption phenomena occur in the wall. This paper investigates the impact of solar radiation on the hygrothermal behavior of a WFH wall under typical French summer climate. The experimental study is performed with a dual-climatic rooms that simulates the indoor and outdoor climates where the solar radiation is taken into account with equivalent outdoor temperature. The test wall is instrumented with temperature and Relative Humidity sensors and with heat flux sensors. The responses of the wall are analyzed from the temperature and vapor pressure kinetics and profiles. Thermal and hygric penetration depth are similar as the ones obtained without solar gains. Heat storage and sorption-desorption phenomena are enhanced by solar gains.