Ductless (multi-split) geothermal (GSHP) ?
Historic house is three-story, 180-years-old, solid brick interior and exterior walls with installed (some badly) ducts. Low-R envelope and resulting high energy $ has driven us toward 9-ton, closed-loop geothermal solution.
And unusual heating and cooling loads and difficulty of installing ductwork through brick walls -- especially to second floor -- make at least partial ductless multi-split from GSHP attractive. (Hydronics alone don't solve cooling need.)
There are plenty of split GSHPs with conventional air handlers available, but seemingly no ductless GSHP systems. Is there a commercial solution? Or would one have to be customed engineered? Seems like some progressive company would have been onto this combination by now.
TIA ... Marc