Anyone know if radiant floors are considered a qualified geothermal expense? I've seen conflicting information all from non-official sources, and couldn't dig up any sort of authoritative ruling by IRS. Has anyone here successfully claimed it? IRS specifically exclude ductwork and back-up heat, but include piping. So is a radiant floor covered under piping and being considered essential to the operation of the equipment, or excluded as an add-on or distribution system? Would it make any difference if I went with something like HydroLogic's modular system where the electric and the piping are all sort of rolled into one package?