Background

To address increasing energy consumption and carbon emissions, there is a need for increased deployment of geothermal heat pumps. Geothermal heat pump systems are a proven renewable energy resource that provide significant energy savings in the range of 30 to 60 percent as compared to conventional heating and air conditioning units currently used in the United States.  High initial installation cost is the primary barrier to geothermal heat pump acceptance in the U.S. marketplace. 

Approach 

 

Today’s geothermal heat pump systems use either propylene or ethylene glycol water mixtures in their ground loop, but ethylene glycol presents an environmental risk and a disposal problem. ACTA Technology, Inc. developed novel nanofluids that increase the heat transfer in the cooling loop of geothermal heat pump systems. These new fluids significantly improve the heat transfer efficiency over both propylene and ethylene glycol. Nanofluids are a type of fluid containing nanometer-sized particles, below 100 nanometers in size. These nanofluids are engineered colloidal suspensions with improved heat transfer efficiency over both propylene and ethylene glycol water mixtures, thereby reducing the life-cycle cost of geothermal heat pump by 17 percent. This improved heat transfer lowers the installation cost and makes installation of geothermal heat pump systems more cost effective.