The architect Roberto Rivero and daylighting research

Abstract

By the end of the 1950’s decade, architect Roberto Oscar Rivero, who had been studying in England, returned to his native Uruguay and produced a revolutionary approach to daylighting techniques: he was able to relate lighting intensities with positions of points located underneath rectangular windows , plotting the result in a simple table. He could do so with the help of painstaking graphs that he drew manually. To introduce the value of the transmittance in his methods he had to define an expression widely quoted by scientists around the world, the Rivero Transmittance Formula, which shows the relevance of directionality in a factor usually taken as scalar in most calculations. This procedure also permitted the study of skies like the CIE overcast sky, which were strongly dependent on the angle of altitude and hence the performance of uniform and overcast skies could be compared. With so many fortunate advances he was on the verge of finding a more general solution to radiative exchange problems, which intriguingly enough, he was not able to produce eventually. Roberto Rivero has passed away recently, and his original texts have almost disappeared as there was no re-edition of this material. Since the manuscripts were conveyed in Spanish, we have felt the necessity to explain his discoveries for an English-speaking audience. In order to do this, we will use a contemporary point of view, and we will discuss how far he could have reached and what he achieved in the daylighting field.