Fred Hutchinson Energy Conservation Measures Generate Major Savings
Fred Hutchinson Energy Conservation Measures Generate Major Savings
A combination of innovative and conventional energy efficiencies is allowing the Fred Hutchinson Cancer Research Center to shave almost $2 million a year from its utilities budget, making the funds available for the institution's research mission.
Guided by the philosophy of delivering the right amount of energy, just in time and as efficiently as possible, the Seattle research center has implemented a long list of electricity, gas, and water projects over the past 10-plus years. The improvements range from the mundane—downsizing lighting ballasts, for example—to the complex, such as reusing the same water stream nine times, reducing the number of air changes according to occupancy needs, and installing Smart Meters for real-time system-wide monitoring. Thanks to these initiatives, energy use in the campus’s 13 buildings, a total of 1.4 million sf under roof, is down 30 percent.
“We cut our energy consumption the old-fashioned way, project by project, one step at a time,” says Bob Cowan, the Center’s director of Facilities Engineering. “These measures are saving a lot of money, roughly $1.4 million a year in electricity alone, at five cents a kilowatt hour. If the cost were 10 cents or 15 cents a kilowatt hour, as it is in many other locations, imagine how much money we’d be saving.”
All About Air
Almost $500,000 in savings—25 percent of the total—came from three projects that targeted air flow in the Fred Hutchinson research facilities, where ventilation and cooling accounted for 66 percent of the energy load.
“It is all about air,” says Cowan. “Every CFM you can reduce is going to save you money, year after year.”
Fred Hutchinson’s first project decreased the number of air changes in Phase 1 labs, built in 1993, from 10 per hour to six, and in the vivarium from 25 per hour to 15.
The original design called for 10 air changes per hour, but according to Cowan that was “overkill” for the needs of biomedical research, which does not involve work with high concentrations of chemicals. When researchers do work with odorous chemicals, they follow good lab practices and move from the lab bench to the fumehood. He points out that many labs can reduce airflow significantly at various points of the day with no impact, especially when no one is in them.
“Under our new scheme, users see nothing,” he says. “They didn’t know they were first getting 10 air changes an hour, and that there was a reduction. Obviously, we had to clear it with the right folks at the right levels, but the typical user in the field does not realize the difference.”
The second project entailed the deployment of a night setback scheme to further reduce air changes, from six per hour to three. Instead of being triggered by occupancy sensors, the setbacks are linked to the low-voltage lighting control system.
The problem with occupancy sensors, Cowan explains, is that because the labs are very equipment-intensive, it would have been very expensive to install the full compliment necessary to ensure adequate coverage.
“A better approach was to tie into the lighting, because it is virtually impossible to work in a lab with the lights off,” he says.
Unlike the first project, the after-hours reduction is visible to lab scientists through a ceiling-mounted device that displays current conditions. A green light indicates that the right number of air changes is being delivered to an occupied lab, while a red light signals occupants that a phone call to the Engineering department is in order.
These two modifications save approximately 1.9 million kilowatt hours and 254,000 therms yearly, generating an annual cost reduction of $387,000. The first project was quite inexpensive, only $3,000 to implement. At $538,120, the after-hours setback was much larger in scope and cost, offset in large part by a rebate of almost $300,000 from the local utility company, in addition to the annual savings.
The third ventilation project focused on reducing the static pressure necessary for the distribution of supply air through the ductwork. Along with changing duct configurations to create a more direct air path, the Center installed a VVVP (variable volume, variable pressure) system from Siemens Building Technologies to match the static pressure to the quantity of air needed at any point in time. Instead of the original fixed setpoint of two inches of static pressure, the VVVP scheme continuously senses and adjusts the static pressure in response to current conditions, another example of right-sizing.
“The amount of air required is dynamically changing, varying with occupancy, equipment heat loads, etc.,” Cowan says. “We are now doing continuous static pressure resets to meet the actual demands of the minute, as part of our overall building controls system. Fifteen of our larger fans are now operating around 1 inch or 1.2 inches of static pressure, depending on the fan. So every day, 365 days a year, 24 hours a day, we are saving a lot of energy via this project.
“You really have to look hard at what the lab’s air change rate was initially set at,” he continues. “System designers don’t know how much pressure will be needed to meet the demand, so they must over-design to make sure the supply will be adequate. The lesson is to question the design parameters, especially on the air side. The original designers weren’t omnipotent, and we’ve all learned a lot in the last ten years.”
Reusing The Water Stream
The multifaceted water-saving projects at Fred Hutchinson focused on glass washing and cage washing operations, among other things.
The initiatives started with the installation of water-efficient glass washers, equipped with conductivity monitors for the deionized (DI) rinse cycle. The monitors sense the cleanliness of the rinse water based on its conductivity, and when the appropriate point has been reached, they reduce the number of rinse cycles, instead of letting them run for a fixed period of time.
“The cleaner the water, the less conductive it is,” Cowan explains. “In the past, the machine had a preset number of rinses, so all our glassware—over two million pieces per year—got that number, even though they may have needed less. Now the decision of how many rinse cycles to run is based on performance. There is no point in over-cleaning.”
In addition to saving energy, the reduction in rinses decreased the quantity of wastewater in the Center’s DI production facility.
The next economies involved making extended use of the water stream, projects that contributed to cutting water consumption in the campus’s two oldest buildings by two-thirds.
“We now capture the hot rinse water coming off the glass wash facility, and we use the heat exchanger to preheat our domestic hot water. These moves enabled us to eliminate hot water tempering, saving over a million gallons a year. Then that water was put into storage tanks, to be used for our Garbel cage prewash facility,” says Cowan.
Continuing the right-sizing approach, Fred Hutchinson facility engineers turned their attention to the cage prewash, which was found to be consuming twice as much water as necessary to ensure that bedding material was flushed out to the main line. An inexpensive fix—installing a timer on the solenoid—dialed back the water flow to the appropriate level.
Total savings from these projects amount to $83,000 and over five million gallons of water per year.
“We are not done yet,” Cowan states. “With that water at a temperature of 105 degrees, we are going to put a heat pump in to recapture the energy at some future time. In all, we will have reused or recaptured the same water stream nine times.”
Turning Crisis into Opportunity
Additional savings were realized when the Center took advantage of an equipment failure in the large air handling unit serving the vivarium to make the overall system more energy efficient. A redesign had been planned but not implemented due to the difficulty in finding an adequate replacement AHU to serve temporary needs. The failure—a damaged fan that subsequently dislodged a 2,000-pound,150-horsepower motor—triggered the need for action.
“Disaster struck, and we had no choice but to live with an air supply that was a little less than optimal for a short period of time,” comments Cowan.
The repair encompassed a total of 20 different improvements to the system. For example, the old humidifier, poorly placed just six inches in front of the cooling coil, had required a host of booster humidifiers in order to perform to the desired level. A new, energy-efficient humidifier, properly located, has eliminated the need for most of the booster capacity.
Other energy conservation measures incorporated in the project include variable speed drives, high efficiency fan wheels, filter bank relocation, and a significant improvement in discharge static pressures.
“We improved the system in 20 different ways, solving eight reliability issues, eliminating two parts-availability challenges, and introducing seven maintenance enhancements and six conservation initiatives,” says Cowan. “As painful as it was, we made the best of a bad situation.
“The real beauty of this project was that it wasn’t as expensive as one might think,” he continues. “It was a $200,000 project, but we got $75,000 in rebates from the local utility for the energy initiatives and $77,000 from the insurance company. Our energy savings over a few years will pay for the air handler. We went from ‘a maintenance zero’ to an energy hero.”
While the AHU equipment “disaster” was turned into a success, an energy-saving measure can occasionally have unintended consequences. Cowan uses the example of how motion detectors interrupted the breeding of transgenic mice was to illustrate this point.
The motion detectors were installed in the vivarium corridors and transmitted at a frequency of 25,000 hertz, inaudible to humans but definitely audible to the transgenic mice, whose hearing range extends up to 90,000 hertz. Every door opening generated very disruptive random noise.
“It was like a 747 buzzing the mice at six feet, and the randomness was stressing them out. We should have known, since the submittal stated ‘Solid state crystal control, 25,000 hertz.’ The problem is we were thinking in our spectrum and failed to realize the mice operate in another. This is an energy conservation project that could have become a disaster,” Cowan warns.
Invest in “Smart”
Online monitoring of energy consumption has also proven to be a very effective conservation tool. A few strategically placed Smart Meters enable Fred Hutchinson personnel to view building performance in 15-minute increments on a website under the Seattle Meter Watch program.
“We can see when the building starts and when it stops. We combined this with traffic survey data telling us when people were coming into the building and, more importantly, when they were leaving. With these two information sources, we were able to really cut back on the operating hours of our building, saving $80,000 over three years in one office building alone.”
The Seattle Meter Watch has also uncovered problems that might otherwise have gone undetected, such as malfunctioning economizers and disabled unoccupied points.
Even more effective than Smart Meters, however, are smart people, Cowan notes.
“Our real energy advantage is that we’ve got a great team at Fred Hutchinson. If you really want to save money in energy conservation, invest in your facilities management team and your operating engineers. Train them, make sure they are skilled, and make sure they are dedicated and motivated, and you’ll be amazed at how much energy you can save,” he concludes.
By Nicole Zaro Stahl
This report is based on a presentation by Cowan at Tradeline’s 2010 International Conference on Research Facilities.