Publication Date


Document Type


Committee Members

Haibo Dong (Committee Member), James Menart (Advisor), James Menart (Committee Member), Rory Roberts (Committee Member)

Degree Name

Master of Science in Engineering (MSEgr)


The rise in fossil fuel consumption and green house gas emissions has driven the need for alternative energy and energy efficiency. At the same time, ground loop heat exchangers (GLHE) have proven capable of producing large reductions in energy use while meeting peak demands. However, the initial cost of GLHEs sometimes makes this alternative energy source unattractive to the costumer. GLHE installers use commercial programs to determine the length of pipe needed for the system, which is a large fraction of the initial cost. These commercial programs use approximate methods to determine the length of pipe mainly due to their heat transfer analysis technique, and as a result, sometimes oversize the systems. A more accurate GLHE sizing program can simulate the system correctly, thus, reducing the length of pipe needed and initial cost of the system. We feel a more accurate GLHE sizing program is needed. As part of a DOE funded project Wright State University has been developing a ground loop geothermal computer modeling tool, GEO2D, that uses a detailed heat transfer model based on the governing differential energy equation. This tool is meant to be more physically detailed and accurate than current commercial ground loop geothermal computer codes. The specific work of this Master's thesis first includes a detailed literature search of GLHE sizing techniques. Secondly, this work contains a detailed description of commercial GLHE sizing codes currently available and compares some results to GEO2D. Additionally, this work has developed a g-function program; a GLHE sizing technique used by many commercial programs, and compared results to GEO2D. Next, this work has developed subroutines to develop a three-dimensional grid system for a horizontal and vertical GLHE. Lasty this work has developed computer code for the boundary conditions and material property allocation used in GEO3D.

Page Count


Department or Program

Department of Mechanical and Materials Engineering

Year Degree Awarded