Contractor: Strategic Energy Solutions | Berkley, Michigan
The vertical closed-loop ground heat exchanger consists of 39 boreholes, drilled to a depth of 340 feet each. The system utilizes a 20% propylene glycol solution. The original design called for the header pipes to run five feet below the ground so that they would sit beneath the frost line.
However, upon encountering an unmarked, abandoned gas line on the site, the header pipes were installed approximately four feet below ground and were covered with two-inch rigid insulation to serve as a thermal blanket. After installation was completed, the trenches were filled with sand and compacted to 95%.