Discoverytester
The ambient definition (coefficient and ambient temperature) is used to calculate convective heat transfer. By default any thermal setup has this convection BC and if user wants to get rid of it, you can simply use 0 as the convection coefficient and this should make the default BC redundant. Unfortunately, deleting this BC doesn't appear possible.
While I tried and found this workaround to be working well for me, please let me know if you are having some unexpected observations with this approach.
You are navigating away from the AIS Discovery experience