Thermal behavior analysis of different multilayer façade: Numerical model versus experimental prototype

In this paper, different sorts of facades have been analyzed considering their thermal performance along a 24 h period. A numerical model was developed and compared with experimental measurements considering two different facades for buildings: on one side an opaque multilayer facade; and on the other side, a ventilated facade. The numerical model representing the temperature in every layer of the facades was successfully validated. This model was used for determining the thermal behavior of two new ventilated facades in which the thermal mass had been changed, observing then that the existence of the movements in the air gap affected particularly the air temperature and the thermal transmittance of the facade while the sun hitting the facade, leading to a reduction of transmittance close to 30% along the air chamber. This effect is very important in warm climates and becomes a key-factor for decreasing the cooling needs of buildings in summer with no need of increasing the mass of the facade.