Light Efficiency on Horizontal Surfaces at the Solar Radiation Station and High Quality Lighting from the IDMP in Madrid

Abstract

At the solar radiation and daylighting Spanish station of the International Daylight Measurement Program (IDMP) located at the Technical School of Architecture in Madrid (40º 25’ N, 3º 41’ W) we have studied the luminous efcacy of global, diffuse and direct solar radiation on a horizontal surface for all sky conditions (clear, overcast and intermediate). The experimental data used are mean hourly values of global and diffuse illuminances and irradiances measured on a horizontal surface during 15 months. We have used these data to develop the empirical models for illuminance, irradiance and luminous efcacy of global, diffuse and direct solar radiation, for all sky conditions as a function of the solar altitude at every 2,5º interval. The main result is verify that is possible to develop a luminous efcacy model from illuminance and irradiance models developed previously, that is very useful to estimate daylighting levels in building.