Errors in the ep-material library - Generic Insulation

imansheikhansari · September 15, 2022, 6:54am

During my lectures, I always emphasize double-checking the library data with the source. However, when I discuss specific errors in the library with one of my colleagues, I figure out that many scholars are unaware of these simple errors. Like in this example, the thickness of both 25 mm and 50 mm insulation is considered the same(50mm).
I do not know where we should report these sorts of errors. I wondered if anybody knew how to report these issues. Please let me know.

chris · September 19, 2022, 6:12pm

Thank you for finding and reporting this bug, @imansheikhansari

This forum is the correct place to report it and you are right that the thickness of the 25mm generic insulation material has not been set correctly. I had looked over these default material properties several times but I still somehow managed to make this mistake.

Luckily, the only place where this particular material is used is in the default construction for opaque doors. So the part of the model that it impacts is small and also the difference in insulation thickness isn’t too different from what it’s supposed to be. Furthermore, people typically overwrite this default door construction using a construction set that is sensitive to a given climate. So hopefully this means that this bug should not affect people’s energy simulation results too much, even though it’s happening in a relatively critical part of the software.

I pushed a fix for it here:

Given where these generic default materials sit in the installation package, running the Versioner component won’t be able to fix it for people but it will be available after people do a complete uninstall and reinstall. So people who really need this fix might have to do it manually until the next stable release. To fix it manually, people can navigate to the file here:

C:\Users\[USERNAME]\ladybug_tools\resources\standards\honeybee_standards\energy_default.json

or here

C:\Program Files\ladybug_tools\resources\standards\honeybee_standards\energy_default.json

Then, they can open the file in a text editor and just change this line so that the thickness is 0.025:

github.com

ladybug-tools/honeybee-standards/blob/master/honeybee_standards/energy_default.json#L351

    
      
              "density": 1280.0,
              "specific_heat": 840.0,
              "thermal_absorptance": 0.9,
              "solar_absorptance": 0.8,
              "visible_absorptance": 0.8
          },
          {
              "type": "EnergyMaterial",
              "identifier": "Generic 25mm Insulation",
              "roughness": "MediumRough",
              "thickness": 0.05,
              "conductivity": 0.03,
              "density": 43.0,
              "specific_heat": 1210.0,
              "thermal_absorptance": 0.9,
              "solar_absorptance": 0.7,
              "visible_absorptance": 0.7
          },
          {
              "type": "EnergyWindowMaterialGlazing",
              "identifier": "Generic Clear Glass",

Thanks again for reporting the issue, @imansheikhansari .