March-April 2010

Charged With Care

Hospitals lead the facilities sector with onsite power and sustainability.

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Photo: Burns & McDonnell

By Ed Ritchie

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The VA has the funds to pursue these projects, with about $31 million to implement projects that come out of feasibility studies. Two projects funded with conventional dollars are the Togus VA Medical Center, Maine, and the White River Junction Medical Center, Vermont. Feasibility studies are completed, and, when environmental assessments are finished, construction will begin on CHP systems fueled in both cases with biomass.

Solar Shines at 20 VA Sites
In 2008, the VA put in solar arrays at medical centers in Dallas, TX, and Loma Linda, CA. “We awarded contracts to install solar PV projects at 18 additional sites, and those include a couple of national cemeteries, so it’s not just our hospitals,” notes Cordova. “Under the Recovery Act, we’ll be doing feasibility studies at 31 additional sites.”

Cordova’s department is also working on the concept of energy-saving contracts in four regions, using energy savings performance contracts and also, in some areas, using utility energy services contracts. Under utility energy services contracts, the utility handles the installation, but it’s not a given that they would own and operate it.

Photo: Burns & McDonnell
Combustion turbine exhaust diverter valve, Heat Recovery Steam Generation, and the standby boiler are located on the second floor.

The St. Cloud Medical Center in Minnesota is slated for a 600-kW turbine installation and a geothermal ground source heat pump. “We have a mandate that 7.5% of our electricity is both to come from renewable sources by 2013, and our internal goal is to double that,” says Cordova. “Like other federal agencies, we were mandated to meet the goal of 30% efficiency or reduce usage by 3% annually, and this is based upon the square footage of the location. I have to say, for hospitals, that is a real challenge.”

Mandates for Disaster Operations
Another challenge for the VA is a mandate to keep medical facilities operating for a minimum of four days, in the event of a grid outage from sources such as natural disasters or terrorist attacks. Some VA facilities in gulf coast states, such as New Orleans, have opted to extend the time to seven days.

According to Kurt Knight, chief, Facilities Quality Service Office of Construction and Facilities Management at the VA, after 9/11, the VA took a more serious look at physical security and protection for its facilities and worked with the National Institute of Building Sciences to develop a physical security evaluation process to determine its needs for multi-hazard scenarios. “We have a variety of different risks including earthquakes, terrorists, floods, hurricanes, and others,” says Knight. “We evaluated about 150 medical centers which we have deemed mission-critical—about 150 of them—and developed a report on the vulnerabilities and mitigations necessary to address some of these risks associated with those events.”

Knight says CHP is a viable solution for maintaining operations during a disaster, as long as it is economically feasible for a particular location.

Heat Pump Technology Raises Chiller Performance to New Heights
Economics played a critical roll in the choice of technology for a new central plant at the Phoenix Children’s Hospital, in Arizona. The hospital broke ground this year on a $588-million expansion plan, and new facilities, including: a new 11-story patient tower, an 18-unit Ronald McDonald House, and a Level One Pediatric Trauma Center, plus a new central plant to handle the increase in hot and chilled water loads. Originally, the plant was designed with a conventional boiler and chiller, but that changed when Johnson Controls, Milwaukee, WI, showed planners how they could achieve significant operating savings by using heat pump technology.

The heat pump chiller cogenerates heating and cooling from just one source of electric power and reduces loads on the boilers, and that saves significant amounts of natural gas. For example (based on manufacturer’s specifications and estimates), the conventional design would have burned natural gas at a rate of 126,360 MMBTU per year. The alternative design reduces natural gas consumption by 70% to 37,430 MMBTU per year. Yes, electricity usage goes up, but it’s a marginal increase from 41.79 million kWh to 46.46 million kWh per year (10%).

“From the hospital’s perspective, we wanted to go with green building guidelines for healthcare as our baseline, and that’s how we started with the design,” explains Dave Cottle, executive director of planning, design, and construction for Phoenix Children’s Hospital.

The hospital added a professional consulting engineering firm, ccrd partners, Greenwood Village, CO, to execute their design, but when Johnson Controls introduced their heat pump solution, the operation became a dual prime contractor relationship.

“We never had to ask ourselves how we would accomplish this,” says Cottle. “The team that we have made a seamless switch from a standard central plant design to the building design we have today.”

The switch may have been seamless, but that doesn’t mean it was effortless, notes Rick Rome, president and CEO of ccrd Partners.

“One of the first things we did to ensure success was come up with a responsibility matrix,” recalls Rome. “We continued to fine-tune that, and it was needed, because one of the biggest obstacles you encounter when you change design and have two prime contractors working on the same scenario is communication. It could’ve gone south if we didn’t sit down and roll up our sleeves to create that matrix which became our Bible.”

The original design specified four, 1,600-ton conventional electric chillers (total capacity 6,400 tons) and natural gas boilers rated at 60,000 MBTU per hour. The revised design specified nine, 3-MMBTU-per-hour high-efficiency condensing boilers with variable-flow primary pumping, three 1,900-ton chillers with variable-frequency drives, and one 800-ton water-to-water heat pump chiller. For standby electric power, two 2-MW diesel generator sets were proposed. 

“It’s not the typical heat pump you see for air-conditioning,” says David Boone, account executive, Johnson Controls. “The principle is that we are recycling the BTUs that we pull out of the hospital’s indoor air stream and feed them back into the heating and hot water side where they can be reused for domestic hot water or heating.”

Basically, the heat pump takes the BTUs out of the chilled-water side that cools the hospital and the water and returns them back to the central plant. A dual-compression mechanical process compresses gas to a high pressure in the condenser side of the chiller, and that increases the temperature from the water on the condenser side to 155°F, for use in the heating hot-water side of the system. On the chilled-water side, the system puts out 42°F chilled water.

“So we are getting two products out of the process, 42°F chilled water, and 155°F heating hot water,” says Boone. 

An additional benefit from such a system, in an area like Arizona or other arid environments, is that taking the heat out of the water and transferring it into the hot water reduces the amount of heat that would otherwise enter the atmosphere through cooling towers.

“It comes back into our building for other usages and that means less use of the cooling tower, which also evaporates water and requires that you constantly make up water,” says Cottle. “In essence, we’re saving about five-and-a-half-million gallons of water a year. That’s a big deal in areas like Phoenix and Las Vegas [NV], where the cost of water is substantial and natural resources are scarce.”

The system also saves an additional 600,000 gallons on discharge to the sanitation and sewer system, because the cooling towers don’t have to be cleaned and blown down as often.

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As we’ve seen from savings incurred at Phoenix and the previous examples, hospitals are leading the way in the facilities sector. Ultimately, with the benefits from onsite energy systems, such as CHP and solar, and new technologies, such as heat pump chillers and building automation systems, these often-neglected institutions are now reaping vast economic and performance gains.

Combined with the benefits of sustainability and reliability, plus ESCO financing, the growth-distributed energy in healthcare looks very attractive for the industry.     


Author's Bio: Ed Ritchie is a writer specializing in energy, transportation, and communication technologies.

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