Hi,

We are doing the day lighting simulation for office building under LEED ID+C v4.1 rating system. We have opted the option 2 simulation approach to meet the credit requirements.

We would like to know the purpose to Calculate illuminance intensity for sun (direct component) and sky (diffuse component).

Calculate illuminance intensity for sun (direct component) and sky (diffuse component) for clear-sky conditions as follows:
 * Use typical meteorological year data, or an equivalent, for the nearest available weather station.
 * Select one day within 15 days of September 21 and one day within 15 days of March 21 that represent the clearest sky condition.
 * Use the average of the hourly value for the two selected days.

Our daylight simulation software has the possibility to consider the clear sky condition as well the software has option to upload weather file. So, whether we need to Calculate illuminance intensity for sun (direct component) and sky (diffuse component)?

Thanks..