UC San Francisco Bulk Sterilizer Upgrade
The Helen Diller Family Comprehensive Cancer Research Building, located in UCSF’s Mission Bay campus, is a state-of-the-art research facility completed in 2009. This five-story building houses critical research being conducted on the biological mechanisms of cancer.
Among the extensive range of equipment in the building are two ‘bulk’ sterilizers, which researchers use to steam sterilize laboratory equipment on a daily basis. However, the sterilizers were determined to be consuming excessive quantities of water, breaking down regularly, and adversely impacting research processes. Meter data showed that the two sterilizers were consuming as much as 10 to 12 million gallons of water per year, with a corresponding utility cost of close to $275,000 annually.
The replacement of once-through sterilization equipment will save millions of gallons of water annually, reduce maintenance and comply with UC system-wide water conservation policies.
Such high consumption is due to the sterilizers’ once-through cooling process, which uses domestic water that is discarded after a single cooling cycle. Use of once-through cooling methods is not in compliance with current sustainability practices of the UC Office of the President, and replacement of such equipment is recommended by U.S. and international agencies, including the International Institute for Sustainable Laboratories (formerly Labs 21), and the EPA. By replacing such systems with re-circulating chilled water systems, water use can be reduced by as much as 99 percent.
Crane hoisting equipment to top of five-story research center.
With water rates projected to increase 6 to 11 percent per year, sterilizer operational costs are expected to increase significantly in the future. A project team at UCSF conducted a comparison with another campus building, where bulk sterilizers are connected to re-circulating chilled water. This building had annual water consumption of less than three million gallons, with a cost of less than $60K per year. Based on metered water data, the project team estimated that replacement of the two once-through sterilizers would provide annual savings of $275,000, with a payback of less than five years. This analysis provided a sound financial case for the project, which would have additional savings in terms of energy use and maintenance, and also improve the research processes in the center. The project team also coordinated with UCSF energy management staff to facilitate the change from domestic water to chilled water.
Installation crew lowering sterilizer equipment through roof hatch.
The installation of the new sterilizers posed several challenges for the project team. As the sterilizers are located in a sensitive area within the building, the removal and installation of the new equipment required significant planning and coordination. The team held several coordination meetings with the research managers to inform them of any potential impacts. Because demolition and construction noise were expected to exceed the maximum established sound criteria of 40 dB, acoustical engineers were consulted, temporary acoustical barriers were installed, and the sound levels were monitored during construction.
The project team also had to contend with the physical limits of the building. The sterilizers, weighing thousands of pounds, were split into two pieces in the factory, lifted by crane into the building via a roof hatch, and then moved through the building to its final designation (which fortunately is on the top floor of the building.) They were then welded together on-site. One minor delay occurred, resulting from the underestimation of the weight of the concrete roof hatch, requiring that a larger crane be brought to the site on the following day.
The project team is currently monitoring the equipment performance, and has verified significant water savings and additional energy savings. The data verification will be used to qualify for utility incentives from the PG&E Savings by Design program, and the San Francisco Water Department’s Water-Efficient Equipment Rebate program. The results may also be used to demonstrate this water conservation strategy for use in other buildings and campuses. At UCSF alone there are 85 sterilizers currently using once-through cooling, and across the UC system, sterilizers can be found in numerous labs that perform biological and medical research, where containers, media and tools require sterilization.
Eliahu Perszyk, Water Program Coordinator with UCSF, notes several important lessons learned from this project: “It is very important to have system-wide policy which can be used as a basis to implement new programs. Sub-metering of large loads in a building, successfully completing large projects, and realizing the resulting utility savings set the groundwork to get approval on future projects with good financial justification.” He notes that the new equipment uses only one percent of the amount of water previously used, and the total building water use has been reduced by approximately 80 percent.
Images copyright UCSF.