Photo No. 1: The Hammer Award







Case Study: Fort Polk Family Housing Energy Conservation Project, Fort Polk, Louisiana

From the “engineer of record” to continuing maintenance of the Ground Coupled Heat Pumps (GCHP), including securing of financing and contract reformation, members of en-Solutions were key participants in the success of this Hammer award-winning project.

This trailblazing project at Fort Polk, which replaced the heating and cooling systems for 4,003 family housing units while lowering the operating costs without using government capital appropriations, was awarded Vice President Gore’s Hammer Award on July 15, 1997.

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the federal government except for procurement and administrative costs. The improvements are being paid for over 20 years by the energy and maintenance cost savings resulting from the retrofit.

When the project was under development, none of the 1.5- to 2-ton GCHPs on the market had high enough efficiency and low enough installation costs to make the project feasible. This obstacle was overcome through the efforts of the GCHP manufacturer, ClimateMaster, Inc., to provide units to project specifications.

This heat pump is a packaged water-to-air unit that is factory-charged with refrigerant, which avoids the problems associated with field-charged, split-system refrigeration systems. Since there is no interface to the ambient air, defrost controls are not required. And because the units are not exposed to the ambient weather, conditions, performance degradation resulting from corrosion, vandalism, or clogging with leaves or mud are not an issue.

Installation costs were reduced significantly by building the pump and valves that circulate water through the ground loop, along with controls, into the unit. This avoids the expense of mounting components on walls and making multiple power and piping connections. It also saves valuable floor space and makes for a more aesthetic installation.

Desuperheaters, which are used for heating the domestic hot water along with the double-wall heat exchangers and circulator for the water from the hot water storage tank, were also built into the unit so that field installation was not required.

The heat exchanger’s underground piping is high-density polyethylene, which is often guaranteed by the manufacturer for 50 years.


The Hammer Award recognizes projects that make government “work better and cost less” and symbolizes efforts to “hammer away” at unnecessary bureaucracy and costly inefficiency.

GCHP’s were installed in a comprehensive energy-efficiency retrofit project at Fort Polk in 1995–1996. The project was carried out under an energy savings performance contract (ESPC). (Ground coupled heat pumps are also known as ground-source, geothermal or water-source heat pumps. The technology is often called “geo-exchange.”)

This is the world’s largest Geo-exchange installation. It has proven that this technology can deliver big energy and maintenance cost savings as the centerpiece of a comprehensive energy-efficiency retrofit project. This massive project, the largest-ever federal ESPC at the time, was funded by $18.9 million in private capital. There was no investment by

Photo No. 2: Heat Exchanger Pipe