Trombe wall management in summer conditions: an experimental study

The application of Trombe walls in temperate climates is problematic due to undesired heat gains and overheating phenomena in summer. A proper shading and ventilation of this system can reduce such drawbacks, but the impact of these strategies on the wall’s thermal parameters is yet not widely investigated in quantitative terms. This paper presents an experimental study on the thermal behavior of Trombe walls in summer under Mediterranean climate conditions. The aim of the study is to determine experimentally the thermal parameters of a Trombe wall in summer conditions through the changing of shading, ventilation and operational conditions. In order to do that a series of experimental campaigns were carried out on a case study. A detailed simultaneous monitoring of two Trombe walls made it possible to compare the thermal behavior by varying the screening, ventilation and internal gains conditions. Furthermore, monitoring of indoor thermal comfort conditions and energy simulation using a model in dynamic state were carried out. The results showed that shading, ventilation and occupancy conditions affect significantly the thermal parameters of Trombe wall in summer: screening with roller shutters determines a decrease in internal surface temperature of the wall of 1.4 C and a decrease in daily heat gains of about 0.5 MJ/m2; the combined use of overhangs, roller shutters and cross ventilation for the Trombe wall can assure a satisfactory thermal comfort level in summer and a reduction of the cooling energy needs respectively of 72.9% and 63.0% for a dwelling with low or highly insulated building envelope in comparison with the case of an unvented Trombe wall without solar protections.