Large discrepancy of daylight and energy results between new and old versions

Hi Mostapha, Chris and all,

I tried to run both daylight and energy simulations using a simple geometry. But I found the there is a huge difference between the results of the two different version of HB (0.056 and 0.058).

It looks really wired. Because I used exactly the same geometry, materials, and other settings, but the results are quite different. For instance, the DLA results in the two versions have two times difference, and the energy load (cooling load and heating load) are also different.

Could you please so kind to check the gh files in attachments, and let me know why there exists so big difference and which one is reliable?

Thank you so much in advance!







CASE_1(newversion) (220 KB)
CASE_1(oldversion) (208 KB)

Hi Ding, We are working on a new release for the 24th. I hope someone can check the files and get back to you sooner but in case that didn’t happen I will check the file after the release.

Hi Mostahpa, thank you so much for your reply.

By further checking all the illuminance values over the year at all the analysis points, I found that illuminance values are kind of the same between two versions (i.e. difference is limited in a acceptable range).

But when I further check/verify the calculation of DLA, UDLI, LightControlProfile (Read Annual Result 1) by using gh native component based on the above mentioned illuminance values, I found that the old version (VER 0.0.56) is reasonably right (because good correlation between calculated and verified values exist); but in the new version (VER 0.0.58), there is not any correlations between calculated and verified values.

I assume it might be good for you to have a look at the comparison of the calculated and verified values before your coming new release, in order to avoid the potential mistakes occurred in the **Read Annual Result 1 **component again.

Ps: Please use the attached files in this reply post. I have added the “let the ladybug/honeybee fly” components in the canvas, which was forgot in my previous post. The simulations will automatically run when you open these files.

Thank you once again.



CASE_1(newversion) (648 KB)
CASE_1(oldversion) (610 KB)

Hi Ding,

The only change between the two releases is the profile. Have you tried to check the occupancy profile output from lightControlProfile? I suspect that the issue is there. I will take a look at your file and let you know about the results.


That was it. The issue was with the input type of Occupancy Generator was set to float and not int. Daysim was generating wrong occupancy schedules from the csv file. It should be fixed now. Check the attached file which is updated to the latest version. I didn’t check the Energy simulation components. (677 KB)