Lately, I had to work with some old simulation results that were made with Honeybee version 0.0.64. Due to the changes in the components, I had to update to the latest version, with which I really struggled to get the same loads as in the original one.
Comparing the IDF files I realized that there was a change in the infiltration calculations, which I managed to correct easily. But, my main problem became the start day of the week. It looks like some part of the code has changed, and though I was using the same epw, the year started on a Thursday while the previous run started on a Sunday, making my cooling load and overheating period increase by close to 5%. I changed the “start day of the week” in the sim par, but it seems that the year takes precedence. I only managed to sort the problem by manually editing the idf to change from 2009 to 2017, to make the year start on a Sunday as in my original run, run the bat file and reload the results.
This part of the code makes me believe I am not currently able to instruct the simulation to start on the day I need it to from GH.
This time it was not a big deal, as I only had to tackle 5 iterations, but usually, I run 200-500. So, manually editing the idf, rerunning and reloading wouldn’t be feasible. Is there a better way to force the start day, preferably from GH?