OT-88-10-1 -- Vertical Ground-Coupled Heat Pumps: System and Installation Equipment Design Projects

Vertical ground-coupled heat pumps are recognized as an excellent HVAC system in both residential and commercial applications. Wider utilization of these systems has been limited by the lack of contractors with the necessary equipment and expertise to install these systems reliably and economically. Student projects were undertaken to develop a design methodology for Alabama. The project was extended to include the design and construction of the equipment necessary to economically install vertical ground couplings.

The initial student project examined current practices of ground-coupling design and installation. Students recommended the use of rotary mud drilling equipment and thermally fused plastic pipe for the couplings. The group also designed and supervised the construction of a pipe fusion machine. A single U-bend ground coupling was installed and tested during a second student project. A third student project resulted in the construction of an 8 hp (6 kW) drilling rig. The student designed the rig to be small enough to be set up in tight residential settings and powerful enough to drill through soils characteristic of the southern two-thirds of Alabama. The rig was used to install a 3-ton ground-coupled heat pump which will be used for experimentation and validation of a computer code for system design and simulation.

Units: Dual