Geothermal Vertical Loop Field - Design and Installation

Geothermal Loop Field Installation Overview

Introduction to the Project

• The video showcases a job site in Columbus, Wisconsin, where a new Family Dental Center is being constructed. The focus is on installing 24 vertical loops for geothermal heating and cooling systems.

Understanding Vertical Loops

• Vertical loops involve boring holes (4-5 inches wide) into the ground to insert pipes, which are then grouted to ensure proper contact with the surrounding soil for effective heat transfer.

Pipe Specifications

• The geothermal loop field uses high-density polyethylene (HDPE) pipe, specifically manufactured for underground applications and compliant with ASTM standard 348. This pipe is not available at typical hardware stores.

• Available sizes can reach up to 20 inches in diameter; however, the installation here utilizes 2-inch iron pipe size (IPS) SDR11 piping. Different SDR nomenclatures indicate varying manufacturing standards and specifications.

Installation Process

• Two pipes extend from depths of 155 feet down to connect via a UB Bend, facilitating circulation within the loop system. Proper design dictates both pipe size and depth based on specific project requirements.

• Grouting is essential during installation as it ensures that air does not insulate the pipes, allowing for optimal heat transfer whether extracting or rejecting heat from/to the ground.

Joining Pipes Together

• A significant aspect of this installation involves joining multiple pipes into one cohesive system using socket fusion techniques for smaller pipes and butt fusion for larger ones, ensuring strong connections that exceed regular pipe strength.

• Socket fusion requires melting both ends of the pipe before joining them together; this process necessitates precise temperature control and timing to achieve a secure bond between components.

Understanding the Importance of Professional Fusion in Loop Field Installation

The Risks of Improper Installation

• If the pipe begins to collapse or melt, it indicates that too much time has passed before removal, rendering the attempt ineffective and potentially affecting flow.

• Certification is required for fusion work due to safety concerns, especially since installations occur 6 to 8 feet underground where leaks can be problematic.

• A leak in the loop field would likely manifest as poor performance inside the building and visible signs outside, necessitating excavation to locate and repair it.

The Role of Professionals

• Engaging a trained professional for fusion is crucial; their expertise ensures a leak-free loop field, which is essential for optimal performance.

• After installing the vertical loop field, the next step involves bringing it into the building by consolidating two halves with supply and return pipes connected to a header.

Installation Process Overview

• Trenching will be done down to the same depth as the vertical loop field, ensuring that pipes remain below ground level when penetrating through the foundation.

• Core holes will be drilled through the foundation for connecting supply and return lines from each side of the loop field into the building.