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Hospital Expecting 25% Fuel Savings With Direct-Contact Heat Recovery

Aug. 1, 2009
System expected to pay for itself in about 30 months

With construction of a new hospital in Hopewell Township, N.J., under way, Capital Health is planning to move its Regional Perinatal Center (RPC) from its Mercer Campus in Trenton, N.J., which will close when the new hospital opens in 2012, to its Fuld Campus, also in Trenton. Hospital officials are gearing up for the new RPC with extensive renovations. The officials also are focusing on Fuld's current and long-term energy requirements.

Fuld's two-level, 1,200-sq-ft energy plant houses three boilers and ancillary equipment used to heat the premises and meet the requirements of the kitchens and sterilization equipment. Looking ahead, more energy will be required, so upgrades to the heating system are part of the overall renovation program.

Initially, installation of a fourth boiler was considered. The downside of that option was cost — roughly $800,000 plus fuel — and increased carbon-dioxide emissions.

King of Prussia, Pa.-based Tozour Energy Systems proposed an alternative solution, one that would cost hundreds of thousands of dollars less than a new boiler and was more compatible with the hospital's commitment to clean, green energy: a Sofame Percotherm direct-contact heat-recovery system.

By increasing the boiler room's energy efficiency from 80 percent to nearly 100 percent, the Percotherm system was projected to pay for itself in less than three years.

The idea appealed to Capital Health's Greg D'Adamo, vice president, support services, and Joe Lake, director of facilities, who asked to visit Percotherm installation sites.

In Montreal, Lake and the project engineers met with Sofame's vice president of technology, Luc Mandeville, PE. Together, they visited Sacre Coeur Hospital, where a Percotherm direct-contact heat-recovery system has been in operation for more than 15 years and annual energy savings amount to roughly 25 percent. From there, it was on to another hospital in Montreal, Maisonneuve-Rosemont, where annual energy savings are in excess of 25 percent. Both hospitals reported a level of greenhouse-gas-emission reductions Capital Health was looking to achieve.

Capital Health elected to attach the heat-recovery system to the three existing boilers.

Cold water enters at the top of the Percotherm system and is uniformly distributed over the upper surface of a packing of stainless-steel nodules, which constitutes the heat-transfer zone. The water percolates through the packing, where it comes in “direct contact” with rising, hot products of combustion. The heated water collecting at the bottom of the unit then is pumped directly to a process or across a plate-and-frame heat exchanger, transferring its energy to a process fluid.

“Because the boiler plant is quite limited in space, we chose to gut an old incinerator room and install the unit there,” Lake said. “In fact, the whole heat-recovery system only requires about 400 sq ft of space, and connecting the condenser to the three boilers is a relatively simple procedure.”

Lake is confident the hospital's annual fuel-cost savings will be at least 25 percent and that the system will pay for itself in roughly 30 months.

Information and illustration courtesy of Sofame Technologies Inc.
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