Ground Source Heat Pump Demonstration at CCHRC
CCHRC installed a GSHP system in the Research and Testing Facility (RTF) in Fairbanks. The GSHP displaced an oil-fired boiler to provide heat to a 5,000 square foot space.
CCHRC previously partnered with the Alaska Center for Energy and Power (ACEP) to study the potential energy savings of using ground source heat pumps (GSHP) in several Alaska communities. ( Ground-Source Heat Pumps in Cold Climates) The goal was to look at GSHPs as an efficient space heating option for Alaskans in parts of the state that rely on expensive diesel for heating. The study found that GSHPs could provide significant cost savings for residential and commercial consumers in some communities—including Juneau, Fairbanks and Seward.
Yet there are still unanswered questions about GSHPs in cold climates, including their long-term efficiency and their effect on ground temperatures.
Because GSHPs extract geothermal energy from the earth instead of burning fuel to generate heat, site-specific considerations are critical in ensuring reliable and efficient heat pump operation. The land around CCHRC formerly contained permafrost up to the surface, but changes in surface conditions have thawed it down to approximately 25 feet. This provides a narrow layer for optimizing a ground loop between the zone of seasonal frost and the underlying permafrost. These are challenging conditions for the operation of a heat pump system and provide a rigorous testing environment for GSHPs in Alaska.
This project also looks at potential changes in the thermal regime of the soil. For example, does harvesting geothermal heat lower the temperature of the ground and thereby lower the efficiency of the heat pump? In addition, how do different surface treatments, like grass or rocks, affect the thermal recharge of the loopfield?
Lessons learned during the design, installation, and maintenance of the GSHP will provide valuable insight into the potential of GSHPs in Alaska and the optimal design for cold climates.
See a video of the installation here.
This project is jointly funded by the Alaska Energy Authority and the Denali Commission by a grant from the Emerging Energy Technology Fund.
GSHP Performance During First Two Years: Two Year Update
Ground Source Heat Pump technology assessment: Ground-Source Heat Pumps in Cold Climates
ASHRAE article: GSHP_ColdClimatesASHRAE.pdf