Charleston Air Force Base
The Challenge
The residential housing at Charleston AFB had original design split-system air conditioning units with natural gas furnaces for heating. The units were becoming an ongoing maintenance concern – they were old and reaching the end of their useful life. Another major concern was carbon monoxide poisoning, a real possibility with the older units. No capital funding was available for these urgently needed improvements.
Our Solution
Under an Energy Savings Performance Contract (ESPC) valued at $9.2 million, AmerescoSolutions was chosen to design, install, and finance energy cost saving measures. Using a geothermal closed-loop strategy, we replaced the old equipment with new ground-source heat pumps. The advantage of the closed loop is that no fluid was taken from or rejected to the ground. Thus the ground acts as both a heat sink and a heat source for the heat pump unit. When a heat pump is in the cooling mode, heat is drawn from each residence and rejected through the ground loop to the soil surrounding each of the boreholes. Conversely, when a heat pump is in the heating mode, heat is drawn from soil surrounding each borehole and transferred into the residence. In addition, all the units have a factory-installed desuperheater to supplement domestic hot water heating requirements when the heat pump is in cooling mode.
Impact
The installed improvements offer annual energy savings of over $800,000. These savings, not taxpayer money, were used to fund the projects. In addition, the projects will reduce energy consumption at the base by 40%, exceeding Presidential Executive Order 13123.
Testimonial
“Ameresco developed innovative installation procedures to minimize the disruption to housing residents and to speed up the installation. Thanks to their efforts, said a Charleston representative, construction finished in April 2001, two months ahead of schedule.”
