Simulation Software-EnergyPlus

Dear LEED Users,

I've got a question to the “IE Q Credit 8.1: Daylight and Views—Daylight"

The Text says "[..] OPTION 1. Simulation - Demonstrate through computer simulation that the applicable spaces achieve daylight illuminance levels of a
minimum of 25 footcandles (fc) and a maximum of 500 fc in a clear sky condition on September 21 at 9 a.m. and 3 p.m. [..]".

I simulate with Dialux, should I define: “clear sky conditions” WITH or WITHOUT direct sunlight?

Thank you very much!

Hsin-Yi Hsieh,
As I know, energyplus uses the split flux method which is not really accurate for predicting daylight but it will be sufficient for the energy calculation. Until now, there is no requirement in the LEED that we have to use radiosity or ray trace simulation engine. I think it may be allowed as long as you can produce the LEED requirement although it may not be the best approach.

Klaus Klimke,
There is no detail requirement whether we use with or without. Typically, you should use without. With direct sunlight, it will give u advantage to achieve the requirement and more realistic approach in certain climate location. However with the updated requirement which has 10 fc as its minimum. Thus, In my opinion, either way should be OK.

Waht are other acceptable programs? We are experimenting with IES but I'm worried about the area differences in the reports and I haven't really heard anything about Reviewer's responses to the IES analysis.