I am modeling a school in which we are using several water-to-water geothermal heat pumps for our domestic water heating. I am assuming I should be able to get significant energy savings in comparison to a standard electric water heater. How do I model this between my baseline and proposed? Can't I use the ASHRAE minimum required efficiencies for an electric water heater based on the BTUH's needed and compare the energy usage to my W2W Heat pumps? My LEED reviewer did not like this approach the first time around. Thanks!