Burying high energy costs
At the new Cambria County Prison in southwestern Pennsylvania, officials faced a dilemma in their efforts to keep the staff and inmates cool in the summer without straining the county’s operating budget. The solution, they found, was right under their noses. Or, to be more precise, right under their feet.
To solve the problem, Cambria County acquired a geothermal heating and cooling method called GeoExchange that uses natural resources to power air-conditioning and heating units, heat water and regulate indoor temperatures. The method substantially reduces monthly energy bills and promotes a clean environment, both indoors and outdoors. (GeoExchange is a registered service mark, or catchphrase for the geothermal industry and geothermal equipment.)
Cambria County Prison, a modern facility built to house 330 inmates, is the largest correctional institution yet to use the technology. Across the country, however, many cities and counties also have begun using it in city halls, office buildings, courthouses, schools, fire stations, police stations, juvenile detention centers, libraries, welcome centers and museums.
In the southern United States, geothermal systems provide heating, cooling and hot water for more than 5,500 housing units at Fort Polk in Louisiana and the Little Rock Air Force Base in Arkansas. The HUD-supported housing authority in Wilmington, N.C., also recently installed geo-thermal systems to serve residents of three apartment complexes – a total of 339 units. The Park Hills, Mo., municipal building also uses GeoExchange.
GeoExchange can offer significant operating cost savings because it relies extensively on Mother Earth’s own natural energy, minimizing the need to burn fuels. Other features include dust-free ventilation, the ability to smooth out uneven patterns of heating in various interior areas of a building and the ability to program individual room temperatures for changing uses or occupancy rates.
How it works A geothermal system collects the earth’s natural thermal energy by employing a series of underground pipes called ground loops that are installed beneath or adjacent to a building. A fluid – usually water or a mixture of water and an environmentally safe anti-freeze – flows through the ground loops, performing the actual exchange of thermal energy with the soil (a process that gave rise to the technology’s name).
At the 126,780-square-foot Cambria County Prison, the ground loops consist of 1 1/4-inch polyethylene pipes sunk into 134 boreholes, each 250 feet deep. In the summer, the fluid cools as it passes through the ground loops. Other pipes then carry the cooler fluid indoors to heat pumps located throughout the building.
Finally, air handlers distribute cool air to the prisoners’ quarters, administration area, laundry room, food service area, medical area, exercise room and other areas. Additionally, instead of dispersing unwanted interior heat outside the building in the summer, the system uses it to provide the prison’s hot water.
In Cambria County, which is nestled in the Allegheny Mountains east of Pittsburgh, the outside air temperature typically swings from 95 degrees F. in summer to -10 degrees F. in winter. Geothermal technology takes advantage of the fact that the soil temperature below the earth’s surface remains relatively constant at about 45 to 65 degrees F. year-round.
In winter, when the outside air temperature plunges below freezing and the prison requires heat, the system uses the soil’s natural insulating properties. The indoor heat pumps extract heat from the relatively warmer fluid circulating in the ground loops, compress it to an even higher temperature and distribute it through the buildings’ air handlers.
The prison’s system can draw heat from one area of a building that is too hot and transfer it to another area that is too cold. Such uneven patterns of heating can be a problem in buildings, particularly those with one side regularly facing the sun.
The geothermal wells, or the piping, are not visible because the boreholes have been backfilled and the field covered. But below ground, the pipes are silently hard at work, taking what nature offers.
Seeing is believing The system has kept the prison’s monthly energy bills startlingly low. In fact, geothermal heating and cooling should allow the prison to cut its annual energy costs by $52,800, according to Ebensburg, Pa.-based L. Robert Kimball Associates, Architects and Engineers, which designed the Cambria County system.
The county also expects to save $41,837 annually on maintenance costs – savings that result in part from the modular nature of the mechanical system, which allows for minor glitches. For example, the malfunction of one indoor heat pump does not shut down the entire air-conditioning system; it requires only the change-out of a single piece of equipment.
Additionally, all the heat pumps in a geothermal system are located indoors, where they are shielded from vandalism or from mechanical failures caused by severe weather.
“Basically it’s maintenance-free,” says Bill Patterson, the prison’s maintenance supervisor. “All we do is change filters and [apply] a little greasing now and then.”
Being able to control the entire heating and cooling system from his computer also appeals to Patterson. “Changing a room temperature at the prison is as simple as pushing a button on a computer keyboard,” he says. “And if a fan belt breaks in an air-handling unit, the computer tells you where the problem is. You don’t have to go checking 64 different heat pumps.”
Geothermal system installation costs often are significantly higher than those of traditional HVAC systems. The installation cost of the prison’s system was $235,900 higher than that of a conventional system, but lower operating costs mean quick recovery of first-cost premiums.
Cutting costs As in Cambria County, a geo-thermal system has resulted in significant savings in a Dorchester County, Md., school. Although the 45,000-square-foot Choptank Elementary School is twice as large as the one it replaced, it uses far less energy. Robert Rader, supervisor of facilities planning for the board of education, estimates that the system will save the county $400,000 in energy and maintenance expenses over the next 20 years. A life-cycle cost analysis prepared by Wedgco Engineering in Rockville, Md., showed Dorchester County’s internal rate of return on its investment to be 98.6 percent.
Rader says that Choptank was the only public school on Maryland’s eastern shore at which students felt comfortable at the start of the fall 1997 term. “At all other schools in the county, students entering the buildings shivered from blasts of cold air put out by conventional air-conditioning systems running full tilt,” he says. Rader has since become an enthusiastic supporter of geothermal technology and has worked to convince state officials to require all school districts in Maryland to consider it.
Geothermal systems also present environmental advantages. According to EPA, since heating and cooling with geothermal power reduces the need to burn fuels, the systems can reduce greenhouse emissions by 40 percent.
President Clinton cited that benefit in October 1997 when he called geothermal systems an innovative means for addressing global warming. GeoExchange has provided the Department of Defense a way to meet Clinton’s mandate for all federal agencies to cut their energy consumption 30 percent by 2005, while also saving money.
To further awareness about geothermal technology, the Geothermal Heat Pump Consortium in Washington, D.C., sponsors demonstrations and confidence-building programs around the nation in cooperation with its members across the country. The non-profit group offers training programs for contractors, and it has worked to remove barriers to GeoExchange, such as local laws that inhibit issuance of drilling permits for ground loops. As the number of experienced contractors and trained technicians mounts nationwide, installation costs have been decreasing to a level comparable with that of conventional systems.
As environmental concerns increase, the need for alternative methods of heating and cooling becomes increasingly important. Cambria County Prison and Choptank Elementary School have demonstrated the cost savings and low maintenance requirements of geothermal systems, which maintain consistent temperatures and also reduce dangerous greenhouse gas emissions.
Bob Livingston is a Wheaton, Md.-based freelance writer.
When Houston started outgrowing its city hall and even its city hall annex several years ago, city officials started leasing office space to accommodate the increasing number of employees in the public works department. By 1995, the city was spending more than $6 million a year in lease payments for office space in a half-dozen locations downtown.
Mayor Bob Lanier, a former real estate developer and investor, suggested acquiring and renovating one or more of Houston’s vacant downtown buildings. However, most of the available buildings contained asbestos, which presented an expensive problem for potential buyers.
After examining several downtown buildings, Houston public works officials selected a 30-year-old, 27-story building with two additional floors below street level. It also had a six-story annex atop an adjoining 228-car parking garage. The 700,000-square-foot building was situated right in the middle of one of downtown’s most desirable locations and across the street from the existing city hall campus.
The renovation required that the building be stripped completely. The electrical distribution system was moved from the floors to the ceiling space to provide greater flexibility; and a new fire alarm and a sprinkler system were installed. The air duct system in the ceiling space was retained, but all other elements of the HVAC system were replaced, and a new digital energy management system was installed.
The addition of structural reinforcement to exterior walls nearly doubled the building’s wind load, bringing the facility into compliance with current codes. New ADA requirements also were addressed. Finally, a tunnel was constructed to connect the building to the city’s existing underground tunnel system and to the city hall and city hall annex.
The city purchased the building for $7.25 million and spent more than $50 million on the renovation. Asbestos removal and demolition totaled $5 million; tunnel connections, $3 million; project management and design fees, $6 million; chillers, boilers and cooling towers, $1.2 million; core and shell renovations, $28.8 million; and phone system, furniture and computer infrastructure, $6 million.
Houston city employees started moving into the “new” building this year, and 1999 will be the first full year of occupancy. The city expects to save approximately $160,000 annually, accounting for rent saved and debt service.
This article was written by John Murph, president of 3D/International, Houston.
Located on the western shore of Narragansett Bay, North Kingstown, R.I., boasts several slate-roof buildings that are listed on the National Register of Historic Places. The city also boasts a large population of seagulls with a hearty appetite for clams.
The combined elements posed a serious problem for Bob Canarri, facilities project manager for North Kingstown, who discovered that the seagulls had done considerable damage to the buildings by dropping clams on the roofs. Slate, a naturally hard substance, served as an effective means for hungry seagulls to break open the clamshells.
After large pieces of slate, some 14 to 18 inches long, slid off the North Kingstown Town Hall onto the sidewalk, Canarri was forced to block walkways and also drape protective canopies over all but the front door of the building, and he began seeking a permanent solution. Because the North Kingstown Town Hall is an historical building, however, it was important to find a product similar to the original.
Canarri first looked at slate and slate-like substitutes. Estimates to repair just the damaged areas of the roof with slate ran as high as $38,000, and Canarri had no guarantees that the remaining sections would not need repair in the near future. “‘Fake’ slate looked artificial and had poor warranties,” Canarri says. “I was concerned about it holding up under our freeze-thaw cycles and the persistent seagulls.”
He found a replacement for the 107-year-old slate in Grand Manor Shangle, an asphalt fiberglass shingle substitute from Valley Forge, Pa.-based CertainTeed. Because it features two full-size, one-piece base shingles, random 8-inch tabs and shadow lines, it gives a roof the depth and dimension of slate.
The shangle is also softer than real slate, meaning that dropped clams bounce off the roof instead of breaking open. Canarri was convinced the shingle substitute would do the job; however, fearing the asphalt roof would compromise the historic value of the building, the Rhode Island Preservation and Heritage Commission was initially less enthusiastic.
Canarri then invited members of the commission to look at a shangle-roofed home in Milton, Mass. The commission agreed that the roof was a satisfactory imitation of slate and approved its use on the historical building at a cost of $37,000.
San Francisco is celebrating its second season in the newly renovated and seismically sound War Memorial Opera House, an historical landmark dating back to 1932. The original 238,500-square-foot theater, the first municipally owned opera house in the United States, was severely damaged by the 1989 Loma Prieta earthquake and underwent a full seismic upgrade and reconstruction last year.
The Opera House remained open until late 1995, despite visible damage from the earthquake. Investigations showed that the theater was structurally safe, but a seismic overhaul and facelift were long overdue.
The building is listed on the National Register of Historic Places, and, prior to the renovation, it had never been physically altered. Several local firms were called in to perform the seismic upgrade as well as to preserve the original design of the theater. They included EQE International (engineers); Structus (engineers); F.W. Associates (electrical engineers); SJ Engineers (mechanical engineers); Auerbach & Associates (theatrical engineers); Morse Diesel International (general contractors); and Turner Construction (management). Carey & Co. architects served as preservation consultants and designers.
“It was very important to do it right,” says Tara Lamont, project manager for the San Francisco Bureau of Architecture. “We wanted to do the whole project so it looked as if we’d never been there.”
After a major fund-raising campaign established $86.5 million in construction funds, the city had just 18 months to complete the work in order to open in time for the fall performances. Planned projects included the seismic overhaul and safety measures, but designers also decided to make many cosmetic improvements. “The finish date was always fixed, but the design kept changing,” Lamont says. “The budget and schedule were hysterical.”
Reinforced concrete shear walls were added, as were steel plates to floor slabs to transfer forces. The ceiling was adjusted for independent movement, and the existing clay tile walls were braced. More than 600 tons of structural steel and 2,300 cubic yards of concrete were used in the re-fitting.
Safety upgrades included new theatrical lighting and sound systems as well as sprinklers and fire alarms. The opera house also was altered to improve access for disabled attendees.
In addition to making the structural and safety upgrades, the builders restored damaged finishes of stone, ornamental plaster, cast stone, gilding and ornamental paint; restored the ceiling; expanded the basement for storage and a performers’ lounge; upgraded the dressing rooms; restored the original restrooms; installed new restrooms and replaced the patterned rubber tile flooring throughout the public spaces.
Only three months into the project, a fire destroyed 11 of the opera house’s 25 original box seats, the opera box vestibules and the mezzanine promenade. Repairing and replacing the damaged areas added $7.5 million to the total construction cost. The fire presented additional problems because designers had to attempt to replicate the damaged fabrics, colors and decorations used in the opera boxes – historically the most expensive part of the auditorium, according to Lamont. “There was panic, but calmer minds prevailed, and the carpenters and architects put their minds to it and finished,” she says.
The design teams completed the reconstruction tasks and seismic upgrades on time, ensuring a safe and well-preserved city landmark. The theater reopened in September 1997 and is used for opera, ballet and theatrical performances year-round.
– Christina Couret