Triple method for daylight annual estimate (DAE) using radiosity

Abstract

In addition to human visual and aesthetic comfort, daylight plays an important role in electricity consumption, as it allows replacing the use of artificial light throughout the day. Currently, there is Dynamic Simulation using Digital Climate Files, which describes the typical annual characteristic of solar radiation availability in many places on the planet. This simulation uses the concept of Daylight Coefficient (DLC), which associates to certain portions of the sky the amount of light that reaches certain points in the environmental surface plans, allowing the estimation of daily/hourly availability of daylight during a typical year. The Radiosity Coefficient (CR) is proposed here, relating the initial illuminance of a certain portion of a surface plane in an inner environment with a Partial Illuminance that, after several inter-reflections, reaches other surface plane portions of the environment from that initial portion. The concept of Daylight Annual Estimate – DAE is presented through a proposal of a triple approach based on Radiosity and using the Radiosity Coefficient, the Daylight Coefficient in a version developed for Radiosity and the new Concept of Full Radiosity (RP). The latter uses integral cycles in the classical method, according to an analysis of the environment that determines which of the three methods is faster for the design’s circumstance. The three methods lead to the same EALN values, optimizing the study´s time and other advantages. Models simulated by the three methods at different degrees of resolution confirm the consistency and reliability of the approach, as shown in the results.