For more information, see Protractor Method IV DF = SC + ERC + IRC = 1.52% % % = % In Boston: Design sky = 7566 Lux (Tregenza formula) Light Level = 7566 Lux x 3.324% = 251 Lux 8ĩ Split Flux Method in Ecotect A geometric version of the Split Flux Method (BRE) Raytracing: each ray represents an approximately equal solid angle of sky Diagrams of raytracing and the split flux method removed due to copyright restrictions. This content is excluded from our Creative Commons license. For more information, see Square One web site 7Ĩ Protractor Method III Andrew Marsh. For more information, see Daylight Factor Protractors Protractor Method II Andrew Marsh. 6ħ Protractor Method I SC ERC Square One web site Andrew Marsh. Limitation in Ecotect: Climate files are not used by lighting simulation. Diagrams of raytracing and the split flux method removed due to copyright restrictions. Thus they also represent a worst - case scenario that you can design to and be sure your building will meet the desired light levels at least 85% of the time.
Questions to ask when choosing a daylight simulation program What do you want to calculate? Has the software been validated? How easy is it to learn? 4ĥ Elements needed for a DL Simulation Building Model Area of Interest (analysis grid) Sky Model Simulation Algorithm Daylight Factor Calculation Methods Average Daylight Factor (Lynes formula see rules of thumb) Original Split Flux Method (Daylight Factor Protractors) Split Flux Method in Ecotect Raytracing/Radiosity 5Ħ Split Flux Method UK Building Research Establishment (BRE) (Daylight Facotr) SC = direct component ERC = externally reflected component IRC = internally reflected component DF= SC + ERC + IRC Design Sky Values Design Sky values represent a horizontal illuminance level that is exceeded 85% of the time between the hours of 9am and 5pm throughout the working year. Competitive edge: high demand for simulationists Opportunity to work on more interesting projects. To be able to engage in a dialogue with the HVAC engineer. To interactively improve your design at the schematic design stage. Visualization Daylight Factor Distribution Who should do daylight simulations? 3Ĥ Architects! Better interfaces. Simulation outputs may be discrete numbers (illuminances and luminances) under selected sensor points within a scene or visualizations of a scene. 1 4.430 Daylighting Christoph Reinhart Daylight Simulations Massachusetts Institute of Technology Department of Architecture Building Technology Program 1Ģ MISC Google DIVA forum,, Most of the concepts discussed in this lecture are covered in Reinhart C F, Simulation based Daylight Performance Predictions, in Building Performance Simulation for Design and Operation, Editors J Hensen and R Lamberts, Taylor & Francis, 2011 Daylight Simulations 2ģ Daylight Simulation A computer-based calculation of the amount of daylight available inside or outside of a building under one or several sky conditions.