How can we ensure that the thermal transmittance takes into account the properties of the thermal asset assigned to the material?

Question

Steps to reproduce the issue

(Using Revit 2021.1.3)

Create materials through Revit API and assign them a thermal asset:
Assign material to a wall layer
See that thermal conductivity is filled but resistance is still 0:

Explored solution

Manual workaround

Manually modify any parameter like commentary
See that this time resistance is now not 0 which means that thermal asset is now taken into account

Things which did not work

Modify commentary through Revit API in a separate transaction

Current work in progress source code

Current work in progress source code can be found in pyRevitMEP repo

score 1 · Accepted Answer · answered Jul 02 '21 at 12:21

I found an example in Revit API documentation. Apparently setting thermal property set through ThermalAssetId property is not the way to go. We need to use SetMaterialAspectByPropertySet method instead.

revit_material = doc.GetElement(Material.Create(doc, layer_name))
thermal_asset = ThermalAsset(layer_name, ThermalMaterialType.Solid)
thermal_asset.ThermalConductivity = UnitUtils.ConvertToInternalUnits(
                    thermal_conductivity,
                    DisplayUnitType.DUT_WATTS_PER_METER_KELVIN,
                )
thermal_property_set = PropertySetElement.Create(doc, thermal_asset)

material.SetMaterialAspectByPropertySet(MaterialAspect.Thermal, thermal_property_set.Id)