EnergyPlus Daylight Control choice between SplitFlux and DELight method

[twanito]

Hi,

I've really enjoyed the addition of the Set EnergyPlus Zone Thresholds component to directly change lighting intensity within a room based on daylighting using EnergyPlus! It's been a great help thanks. However I have noticed that it is set to default to the SplitFlux method to calculate lux levels at the control point which is ok but I would like to do a run using the DElight method, which is more accurate. Any top tips as to how I would go about that?

Should I just add a line of code in the Export to OpenStudio node?

Cheers,

Antoine

[chriswmackey]

@twanito ,
Thank you for posting this. I was actually not too knowledgeable of the different types of lighting calculations when I added it into Honeybee. If you need the change right now, you can do it by adding in a line of code from OpenStudio SDK here:
https://github.com/mostaphaRoudsari/honeybee/blob/master/src/Honeybee_Export%20To%20OpenStudio.py#L2634-L2646
How much longer is the calculation time for the DElight method? If it's not that much longer, perhaps we should just make it the default.

[twanito]

Thanks for looking into this. After reading through this my understanding is that the OpenStudio API doesn't give you the option of changing this. It has to be coded into the idf for energyPlus to read. I'll do a test and let you know how much longer it takes. It might be a clunky patch to mod the idf in the HoneyBee workflow though.

[chriswmackey]

@twanito ,
We actually have a whole class in the OpenStudio component that is devoted to writing in stuff that OpenStudio does not currently support (like CSV schedules, natural ventilation, and Earth Tubes:
https://github.com/mostaphaRoudsari/honeybee/blob/master/src/Honeybee_Export%20To%20OpenStudio.py#L3306-L3700
So adding in the DELite method is not a very big deal from a coding standpoint. If you could confirm that this doesn't increase the simulation runtime much, I would be fine with adding this into the class. Let me know what you end up finding.

[chriswmackey]

I am starting to think that this should be best implemented as an EnergyPlus measure that changes the daylight control input of the IDF. This would also make this change generally more do-able with openstudio models.