BY STEVE SPAULDING

Of CONTRACTOR’s staff

FAYETTE, PA. — When a government — be it city, state or federal — steps up to pay for a public building, it will always demand a heating system both dependable and efficient. But issues of dependability and efficiency become even more important when that building is a prison. Then maintenance and budget issues are at the same time security issues.

The new 672,000-sq.-ft. State Correctional Institution, Fayette, was built to replace an existing prison in Pittsburgh that has grown too old and has too little capacity. It sits atop a 400-ft. precipice on the banks of the Monongahela River, with the nearest bridge (and nearest municipality of any size) nine miles away. The prison’s construction promised an economic shot in the arm for the sparsely populated county.

Civil work on the site included cutting about 100 ft. off the top of the mountain to create a bowl-like shape that would protect the prison from weather and prevent it from becoming an eyesore.

Implementing a heating design would prove as, if not more, challenging. Designers had originally considered large, oil-burning fire-tube boilers, which were then ruled out due to space constraints. But not before principle engineering had been completed, leaving the state with a limited budget to complete the work.

The eventual solution was for a private company, Fayette Thermal, to build, own and maintain a boiler plant located 3,000 ft. away from the prison on its own property. The plant would use bituminous coal tailings in high-efficiency fluidized bed boilers. The waste coal being used in those boilers is one of Pennsylvania’s indigenous fuel sources, which state law demands be the main power source in any new state-funded construction. Many states, by the way, have similar laws on the books.

This left an empty central utility plant on the prison premises, although outside the secure facility walls. The central plant was quickly dedicated to a backup system.

“When there is a problem with service from coal boilers an instantaneous backup is paramount,” said David Goldsmith, a design engineer for Power Consultants, a utility consulting firm hired by the state. “Fire-tube boilers cannot respond like that.”

Three 300-hp Miura natural gas-fired boilers were chosen for the backup. Each is able to provide 9,000 lb. per hour of steam. The space considerations that had moved the main plant three-quarters of a mile away were not an issue with the new boilers. In fact, there’s room enough to install a fourth boiler, in the unfortunate event that the facility should have to expand due to a growing prison population.

“Even the relatively miniaturized waste coal water-tube boilers are over three times bigger than the Miuras,” Goldsmith said.

Cannon Boiler Works of New Kensington, Pa., was the contractor chosen to install them. The job took about six months with a flexible crew size, and encountered no unusual challenges during the job. In addition to the boiler work, Cannon Boiler Works completed the “balance of plant” work as well, which included piping, insulation, hangers, equipment controls, air lines and natural gas supply.

Art Skelley, president of Cannon Boiler Works, said that the choice to go with Miura boilers was based primarily on efficiency.

“There’s two types of efficiency related to a boiler: One is fuel-to-steam efficiency — and theirs is a little better than most manufacturers on the market — but the real savings is found in their in-service efficiency,” he said. “Where other boilers for the same application would require keeping 2,000 or 3,000 gal. of water in the boiler, all of it hot on a constant basis, ready to produce steam, the Miura boilers have approximately 50 to 55 gal. of water capacity that’s kept hot at all times.”

That high in-service efficiency will be key to controlling energy costs at the prison in coming years. Fed Chairman Alan Greenspan, speaking before the U.S. House of Representatives as recently as June 10 expressed concern about the impact of rising natural gas prices on the greater economy.

“Supplies are the real problem right now,” Skelley said. “Looking for new reserves is something that’s going to take three or four years, so we can expect natural gas prices to remain high for the next two or three years at least.”

The much smaller amount of water that needs to remain hot in the high-efficiency boilers not only helps keep standby costs low, it also contributes to their rapid response time. To take a typical fire-tube boiler up to full operating steam pressure would require about112 hours, Skelley said, while the Miura requires 5 to 8 minutes.

That rapid response time is key for an institution with its own kitchen, laundry and showers — and not just for emergency backup, he noted, but also for their additional capacity in the event of heavy demand.

“Just imagine 2,000 people showering in a three-hour period,” Goldsmith said. “If the coal-fired boilers chugging along at the top of the hill can’t respond fast enough to the steam requirements, then of course one of these little Miuras kicks on and almost instantaneously supports the additional requirements.”

While Fayette Thermal owns the three Miuras in the on-site plant (even as it owns the remote plant), they are on a lease-back basis so that eventually the state will own them.

Right now the new high-efficiency boilers are working as more than backup; they’re running the whole show. Until work on the off-site plant is completed in August the Miuras are carrying the entire steam load for the empty facility.