This is an interesting question, I have never tried to output an entire
grid of illuminance levels in a space from eQuest. (Can it do that? Now
I'm intrigued)

But even assuming it can, looking into the language of the LEED v4 credit,
I don't think you can use eQuest illluminance calcs to demonstrate
compliance.

LEED v4 simulation option requires that you calculate illuminance for
direct sun as well as sky. But the calculations within eQuest (and
EnergyPlus for that matter) are basically just daylight factor, so it
calculates an average window luminance based on sky luminance etc., and
then uses that to calculate illuminance at each point. It does not
calculate direct illuminance at a point from beams of sunlight in the way
that ray-tracing methods (like Radiance) or radiosity methods (like AGI32)
can, so I'm thinking it does not meet the credit simulation requirements.

I'm not sure you could even use it to check whether the project as a whole
could potentially comply or not, since limiting direct sunlight (target is
300-3000 lux) at each calc point is such a big part of compliance. But,
eQuest would probably give a decent assessment of illuminance in simple,
non-convex *north facing* spaces, since that is only sky component -- and
if those spaces knock you out of the running for compliance, then you know
you don't need to worry about the rest.

Cheers,
Elizabeth

*Elizabeth Gillmor PE, BEMP, LC, LEED AP*

*e n e r g e t i c s **consulting engineers, llc*
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