russmech,
i know several heat xsfer specialists (somewhat of a generalist myself) and will provide contact information upon request; but not via this forum. please advise if interested. oh! i'm located in ak.
something to ponder...
without knowing details of complex fin and i'm imagining a steel beam exposed to ambient conditions that penetrates bldg insulation envelope, i would imagine the concern is heat xsfer by conduction. is it possible to install a thermal break/barrier between complex fin & bldg to minimize heat xsfer?
lastly, i believe, for the most part, that since you posted a question in this forum and are requesting assistance/direction from fellow engr's, that you may receive beneficial responses from skilled engr's if given the opportunity. this posting may receive a more skilled audience if posted in heat xsfer forum as well.
good luck!
-pmover