Medical center cuts energy costs by 32% via cogen units

Medical center cuts energy costs by 32% via cogen units

NEPTUNE, N.J. — At Jersey Shore University Medical Center, the first hospital here in New Jersey and the largest on the East Coast to receive U.S. Green Building Council LEED Gold certification, two cogeneration units in the central utility plant (CPU) create renewable energy for the entire medical campus, resulting in a 32% reduction in energy costs, which will save more than $1.5 million in the first year of operation.

“What stands out in this project is the size of the project and the attention to detail to be as energy efficient as they could,” said William C. Barham, president, The Barham Group LLC, the project’s mechanical contractor. “Hospitals by nature are very inefficient structures, but the owner of this facility wanted to be energy efficient and have LEED status from the very beginning.”

Design phase

Before the construction phase of the project started, which took approximately three years, The Barham Group was brought in during the design phase to guide the architect, construction manager and engineering firm on costs.

“As we began the design phase of the project it was our mission to provide the architect, engineer, and other consultants with up-to-date costing analysis of the project, as the project design was evolving, and to make design and value engineering suggestions,” said Barham. “These suggestions resulted in substantial savings for the owner while keeping in the forefront the owner’s objectives and uses of the new facility.”

A cost benefit analysis was also done regarding the cogeneration units.

“The cost benefit analysis showed payback of $1.5 million a year and energy consumption savings,” said Robert Adams, vice president of operations at Jersey Shore University Medical Center. “We used that evidence of cost savings as part of our decision process. Initially we were going to install only one cogen engine. When we looked at ROI we decided to install two. We also looked at the need to maintain the power system 24/7 all the time, depending on whatever type of situation presents itself where the utility is out. And the cogen provides this type of back up to carry the medical facility’s load.

“We knew cogeneration would pay for itself in ten years,” added Adams. “We know it would pay in terms of utility savings. Each one of these machines requires $100,000 tune-ups. And we know of this expense and it’s worth it considering the money we are saving.”

Central utility plant

According to Barham, during the normal course of operation the jacket water becomes heated.

“We pipe the jacket water through a series of heat exchangers, and the heat exchangers transfer the jacket water heat and heats the domestic hot water and HVAC heating water,” explained Barham. “The water is then returned to the generator now cooled and the process begins again.

“We then installed ‘boiler type’ water heating coils in the generator exhaust breeching. These hot water coils capture the heat from the generator exhaust, which normally would just be exhausted to the atmosphere, and again the hot water is sent to heat exchangers where the heated water is then piped to a York absorption chiller for its operation. The hospital is then able to utilize this now energy efficient chiller for much of its chilled water needs.”

Boilers by Cleaver-Brooks utilize economizers, which take the exhaust heat from the boilers to reheat the boilers’ water. Thus, water comes into the boiler preheated, saving energy.

The central utility plant consists of primary pumping and all major equipment for cooling and heating of the hospital, and the secondary pumping is in the mechanical rooms of various buildings.

“Primary pumping of hot water and chilled water come from the CPU, which is fed into the mechanical rooms of different hospital areas,” said Barham. “Then the secondary pumping takes over and feeds various buildings’ heating and cooling systems, and feeds the heating and chilled water going to the air handling unit coils.”

Besides installing the mechanical equipment in the CPU, The Barham Group also worked on the diagnostics and testing facilities building, a patient tower, both buildings’ mechanical plants, and all the renovation work on campus.

“We had to go inside many existing facilities and tie them into the new central utility plant which was challenging in itself,” said Barham.

The diagnostics and testing facility, a five-story building consisting of operating rooms, recovery rooms and kitchens, has a series of four air handlers that are approximately 85,000 CFMs each.

“We needed one air handler as a special unit for the operating rooms with redundancy in it for supply and exhaust incase a fan fails,” said Barham.

The seven-story patient tower has its own mechanical room with multiple air handlers that are approximately 85,000 CFMs. The air handlers are two-story units that supply air to the whole patient tower from top to bottom.

The entire medical facility is ventilated with 100% outside air via a York air handling system.

According to Ron Hofer, manager of facilitates at Jersey Shore University Medical Center, no air is being recirculated, and the energy in exhaust air is recovered 80% by the heat recovery wheels that pre-heat and pre-cool the air going down into the space.

“Heat recovery wheels are in all air handling units,” said Barham. “The outside air comes in, and heat wheels turn inside of the air handlers, so the heat is captured going out on the exhaust side of the handler. The heat wheel turns slowly and the outside air, if it’s cold, comes across and is heated by a heat transfer, so that comes in and raises the temperature going into the supply fan.”

Plumbing, monitoring system

The entire medical facility’s water consumption has been reduced by 30%, or 3,600 gallons per day via low-flow plumbing fixtures, and a chemical-free water treatment system also conserves water and electricity while avoiding the release of chemicals into the environment.

Throughout the facility, 1.6-gpf toilets by Toto are being utilized.

“We evaluated three toilet manufactures,” said Hofer. “We wanted to make sure we selected appropriate toilets for this building. We went with Toto because they flushed and we didn’t have any problems. It’s a hospital and infection control is a big issue.”

The building management system is by Johnson Controls along with digital thermostats throughout the facility.

“Investing in digital controls that can be monitored centrally allows better management of temperatures throughout the facility, which saves energy,” said Adams.