Advanced, Low-Cost Indoor Heat Exchanger for Geothermal Heat Pump Systems

Geothermal heat pumps have the potential to significantly reduce residential and commercial energy usage for space heating, air conditioning, and hot water. The largest barrier to wider adoption of this technology is the high installation cost relative to conventional air conditioners, gas furnaces, and heat pumps. The high cost of geothermal heat pumps is due to the high cost of the ground loop and the increased cost of the heat pump relative to traditional air-coupled technology. A novel heat exchanger technology will be developed that increases the efficiency of the system while reducing cost. This heat exchanger technology will couple the heat pump to the ground loop, and is a key component influencing the cost and performance of both systems. In Phase I, a first-generation prototype of the proposed heat exchanger design will be developed. The component’s heat transfer and pressure drop performance will be optimized while maintaining materials and fabrication techniques that will maintain a low-cost, reliable product. Key technical challenges will be addressed, and the prototype will be benchmarked against a state-of-the-art heat exchanger, demonstrating that it meets its performance targets. This heat exchanger will reduce the cost of geothermal heat pumps, improving the market penetration of this technology and reducing energy usage of space heating and air conditioning systems. In addition, the lower cost and improved performance will make it attractive in a number of other applications, including data centers, cogeneration systems, solar thermal systems, and food processing.