Low Cost, Large Diameter, Shallow Ground Loops for Ground-Coupled Heat Pumps

This project will address the high cost of ground heat exchangers (GHEs) for water-to-water and water-to-air heat pumps to facilitate the application of efficient ground-coupled heat pumps in California. The project will focus on shallow (20-30 feet deep) and large diameter (2-3 feet diameter) ground heat exchanger designs using helical coil heat exchangers. The project team will develop models, validate them with field data from two existing sites, identify optimal designs, and develop modeling methods that can be adapted for use with Title 24 standards compliance tools. The project will also produce typical design specifications that will support future Title 24 eligibility criteria. A design guide will be developed for use by the industry as a training aid, and a position paper will be prepared for the Department of Water Resources' California Geothermal Heat Exchange Well (GHEW) Standards Stakeholder Advisory Group.