Abstract EN:

The requirements in terms of energy saving impose a reinforcement of thermal insulation, this strongly influences the transfers of moisture in the walls, moisture which can degrade their performance and durability. The object of this thesis is to study the hygrothermal behaviour of the sandwich panels employed in sever conditions. For this, three test houses were built, one in French Guyana and two in Finland. Three types of insulations with a thickness of 50 and 150 mm were tested : polyurethane foam, glass wool, and rock wool. The rock wool and the glass wool panels were produced by turning their fibres perpendicularly to the surface of steel face sheet in order to improve mechanical properties of the products. The test houses have interior surfaces approximately 10m2 and are equipped with an air conditioning system. In total, 195 probes (temperature, relative humidity, water content, heat flow, wetness, thermal conductivity…) were installed in the panels on the two sites. A specific system of data acquisition at each site was developed and installed in order to be able to follow the measurements from a distance. In parallel, the characterization of the insulating materials was carried out in a laboratory. On the both sites, condensation appeared on the interior surface of steel face sheet. The transfer of moisture is strongly influenced by the directional variation in temperature, the results obtained from the two sites are coherent. The thermal conductivities of insulations varied with the temperature and the water content but these variations remained acceptable. The behaviours of the two mineral wools are closed but polyurethane foam seems less sensitive.