Rating System

LEED BD+C: New Construction

Rating System Version

v2 - LEED 2.0

Inquiry

We have an open-loop geothermal system, which utilizes energy containing groundwater directly pumped to the heat pumps. If this groundwater were pumped through a water coil in the air supply stream, the air would be cooled and heated partly without the use of electrically powered refrigeration. It is this portion of the energy, which should be considered renewable. The system as designed uses two wells with valves and piping so that the function of each well alternates from season to season. In summer, one well is the supply cooling energy source with the other being the heat rejection well and in winter the wells reverse roles. This sequence of operation will actually utilize the groundwater source as thermal storage. On page 137 of the LEED 2.0 Reference Guide, the Design Approach Strategies calls out to use geothermal systems. However ground source heat pumps do not qualify for points under this credit. These are two contradicting statements. Also, on page 122 of the LEED 2.0 Reference Guide, under EA credit 1: Optimize Energy Performance, \' geothermal exchange to extract heat from the ground are all forms of site energy harvesting\'. Would a Geothermal System as described above qualify for credits under the Renewable Energy Systems also? Or would it only contribute to points under Optimize Energy Performance. Please Clarify.