The relevance of a good design in the improvement of the thermal performance of a building turns especially critical in the facades, where some of the most significant heat exchanges between building and environment take place. The open joint ventilated facade (OJVF) is a construction system widely employed as an element of protection against the solar radiation, so a good characterization of the natural convection phenomena is required. This research focuses on the study of the thermal and fluid dynamic behavior of this construction system, paying particular attention to the description of the fluid turbulent structures induced by the solar radiation. With this purpose, five experiments have been performed corresponding to five simulated solar radiation incident on the surface of the facade, and no wind. These cases of study correspond to the following Rayleigh numbers: 1.52 x 10(9), 1.02 x 10(9), 5.94 x 10(8), 4.30 x 10(8) and 4.12 x 10(8). The laboratory facade model tested is a panel structure of 0.825 m high and 0.3 m wide composed of four panels and five corresponding horizontal joints of 5 mm. The air cavity is 40 mm wide. The velocity fields were obtained using the Particle Image Velocimetry (PIV) technique. These experiments have allowed the analysis of the fluid and thermal characteristics of the air flow inside the ventilated cavity, in the different conditions investigated, and to obtain a good description of the natural convection phenomena induced by the solar radiation. Results show that an ascending flow is produced inside the air cavity with a similar flow pattern regardless of the solar radiation incident on the facade. (C) 2013 Elsevier Ltd. All rights reserved.