domestic hot water and the second was
to reduce the required ground heat exchanger requirements. While this reduced
the amount of required ground heat exchanger, the system costs were still
greater than the project could afford.
Further analysis showed through the performance of a parametric analysis with
the DOE-2 software, a reduction in the amount of the ground heat exchanger
would result in a higher loop water temperature with a concurrent increase
in the space temperature. It was finally decided to limit the ground heat
exchanger to between 200 to 220 lineal feet per ton. While this would result
in a slight reduction in cooling capacity at towards the end of the cooling
season, it would result in more heat being
store in the ground that would be available
for winter heating. After careful consideration of the trade-offs, the project
proceeded with the installation of the GCHP systems in all 155 housing units.
Five years after completion, it has been
indicated that there have been no problems with the GCHP systems and that
the tenants are fully satisfied.