Looking at Geothermal vs Nat. Gas for new home construction.  HVAC guy claims that his entire bill (ground loops, heat pump, in-floor heat, ducting, buffer tank...) would be available for the 30% tax credit.  I've found conflicting information on the web.  

The energy star website said "Covered expenditures include labor for onsite preparation, assembly, or original system installation and for piping or wiring to connect a system to the home."

Tax code says...http://www.dsireusa.org/documents/Incentives/US37Fa.htm

"(B) Qualified geothermal heat pump property. The term "qualified geothermal heat pump property" means any equipment which--

      (i) uses the ground or ground water as a thermal energy source to heat the dwelling unit referred to in subparagraph (A) or as a thermal energy sink to cool such dwelling unit, and

     (ii) meets the requirements of the Energy Star program which are in effect at the time that the expenditure for such equipment is made.

  (1) Labor costs. Expenditures for labor costs properly allocable to the onsite preparation, assembly, or original installation of the property described in subsection (d) and for piping or wiring to interconnect such property to the dwelling unit shall be taken into account for purposes of this section.

 The IRS form (Form 5695) says...http://www.irs.gov/pub/irs-pdf/f5695.pdf

Qualified geothermal heat pump property costs. Qualified geothermal heat pump property costs are costs for qualified geothermal heat pump property installed on or in connection with your home located in the United States. Qualified geothermal heat pump property is any equipment that uses the ground or ground water as a thermal energy source to heat your home or as a thermal energy sink to cool your home. To qualifiy for the credit, the geothermal heat pump property must meet the requirements of the Energy Star program that are in effect at the time of purchase. The home does not have to be your main home.

 Has anyone used this credit on new construction?  What was your experience?  Ducting would be part of a system using the ground as a 'thermal energy source' to heat/cool the house.  Of course that same ducting could be used with a regular furnace/AC system as well.