How to remove default materials from idf

oguzhankoral · June 1, 2022, 9:27am

Hi everyone,

For a research project we create thousands of idfs for different scenarious by following Honeybee Schema. Everything is fine, I am just wondering how can I remove default materials (honeybee_energy/lib/materials) and constructions (honeybee_energy/lib/construction) from idf. I am willing to get more lightweight idf file, and to see errors/warnings if we delete these defaults.

Is there any function to ignore them before calling model.to.idf method?

Best regards.

-Oğuzhan

TrevorFedyna · June 1, 2022, 4:03pm

For clarification: Are you wanting to create idf’s that do not have any materials/constructions?
Or: in addition to the constructions intentionally applied to the model there is also unused generic constructions?

chris · June 1, 2022, 5:19pm

Hey @oguzhankoral ,

We have prioritized ensuring that IDF files always have everything that is needed to simulate any Face type over ensuring there are no unused constructions. And I think most of us on the forum would agree that simulate-ability takes priority over removing a few unused constructions.

But, if it really bothers you, you can remove this line of code from your honeybee-energy Python library:

github.com

ladybug-tools/honeybee-energy/blob/master/honeybee_energy/writer.py#L619

    
      
          
          
# get the default generic construction set
          # must be imported here to avoid circular imports
          from .lib.constructionsets import generic_construction_set
          
          
# write all of the materials and constructions
          materials = []
          construction_strs = []
          dynamic_cons = []
          all_constrs = model.properties.energy.constructions + \
              generic_construction_set.constructions_unique
          for constr in set(all_constrs):
              try:
                  materials.extend(constr.materials)
                  construction_strs.append(constr.to_idf())
                  if constr.has_shade:
                      if constr.is_switchable_glazing:
                          materials.append(constr.switched_glass_material)
                      construction_strs.append(constr.to_shaded_idf())
                  elif constr.is_dynamic:
                      dynamic_cons.append(constr)

… and you can replace it with something that only adds the constructions of the generic_construction_set that you are actually making use of in your IDFs.

Hope that helps.

oguzhankoral · June 1, 2022, 5:46pm

Hi @chris,

That was the line I was looking for, it worked thanks!

Altough I don’t think it will effect the performance at all if defaults don’t use in the model, we don’t want to put unused lines into idf in order to catch possible invisible mistakes if so.

Cheers!