The IBM manufacturing facility in Essex Junction, Vermont, is a part of the IBM's microelectronics division. This plant designs and produces logic, microprocessor, memory, and custom microchips used by electronics and computer companies worldwide. The semiconductor computer chips manufactured at this facility are used in many commercial products. Approximately 5,000 employees, including a maintenance staff of 60, work at this plant.
The facility had high electrical costs due to the amount of energy required by the manufacturing tools and the need to maintain tight temperature and humidity controls in the manufacturing clean rooms. This required the plant to operate four 2,000-ton chillers in the middle of the winter, even when the outside temperature was below 40 °F.
The decision was made to modify the existing chilled water system to incorporate a free cooling configuration of the equipment utilizing a spare heat exchanger and a separate bank of cooling towers. Free cooling was evaluated for savings and payback opportunity by recommissioning existing under-utilized equipment to reduce project cost.
The dry frigid air in northern Vermont is used in an evaporative cooling tower to create 42-46 °F water that is then used to cool the site’s air conditioning loads in the winter. The cooling is accomplished without the use of the electric motor on chillers with 42 °F water being circulated through the cooling tower and heat exchanger. The specific arrangement that was installed incorporated a blended arrangement where the free-cooled water mixes with water-cooled by other electrically driven chillers. This makes additional operational hours available to extend savings into the warmer months.
“While there are many free-cooling installations, this installation is different in that multiple follow on projects were completed to increase the savings,” explains Ruma Kohli, product stewardship program manager at the facility. “Vermont has a lot of days when the outside wet bulb temperature is below 40 °F. The solution is very dependent on the skill of the central utility plant operators. The existing condenser water piping and the cooling towers allowed for easy modifications of the system. Reutilization of existing equipment is in line with the site’s mission statement to reduce, reuse, and recycle.”
An outside source of capital funds, the local electric utility efficiency fund, was used, but manufacturing operations could not be interrupted. “The project included increasing the free-cooling load and decreasing the electric motor-driven cooling by upgrading the flow controls on all chillers, installing a much smaller, 500-ton chiller to match the minimum flow requirements of the tower to prevent freezing and enabling more free cooling, converting the 500-ton chiller from a three-pass to a two-pass evaporator, installing heated louvers in lieu of the drip edge at the top of the tower air inlet face to reduce the ice formation, and increasing the heat exchanger capacity by adding more plates,” explains Michael Pelletier, CUP engineer.
The CUP staff developed a concept where 25% of the piping in the cooling plant was reworked from a heating mode to a cooling mode. The staff also was able to implement free cooling on one multi-cell cooling tower while an adjacent cooling tower was still cooling condenser water from electric motor-driven chillers.
Completing the project in a timely manner would maximize the savings from the winter of 2008-2009 after the cooling season. Many construction tasks between trades were accomplished in parallel, instead of sequentially. The system was started one month early. IBMers from many departments volunteered to assist with the construction and startup.
“The dashboard displays in the CUP control room provide a continuous and current display of both cooling load in tons and cost saving in dollars to the lead operator,” explains Pelletier. “Real-time weather data and detail forecasting is also incorporated, so that the maximum possible energy savings are captured.”
This project annually reduces electrical power consumption by 8.5 million kWh, water usage by 3.3 million gal, and chemical usage by 5,000 lb. And because the concept is transferable, it has been implemented at many locations in cold climates.
“The free-cooling project has been a huge success for IBM with savings of approximately $750,000K annually,” says Kohli. “This savings would not have been possible without the joint efforts of engineering, maintenance, and operations.”
IBM’s Center of Excellence for Enterprise Operations develops and delivers best practices for effectively running an installation of more than 30 buildings and 3.5 million sq ft of space. The secure facility includes an electrical grid that peaks at 65 MW, manages 3.2 MGD of water (water supply, industrial water production and wastewater treatment and compliance), building operations and central utility operations.
An expansive integrated network of 60,000 sensors and meters monitors multiple systems, which play a critical role in achieving the quality and reliability requirements that the 24/7 manufacturing operation requires. Data is fully integrated into one repository for basic intelligence such as monitoring specifications, integrated systems data providing relationship intelligence between utilities and building performance, predictive intelligence in advance of maintenance issues, and advanced analytics predicting peak power with automated power load shed.
“Interconnected systems bring all the data together, which allows the team to drive continuous performance improvement with advanced data analysis and analytics,” explains Janette Bombardier, P.E., IBM Vermont senior location executive and director of site operations. “Smart grid, smart water, and smart buildings are integrated to provide continuous operations to a site that hasn’t had a shutdown since 1997. In addition, the team has also driven extensive cost and environmental performance improvement. The site has an outstanding environmental and energy management record receiving at least one Vermont Governor’s Award for Environmental Excellence every year since the award’s inception 17 years ago. It has been named the Facility of the Year by Environmental Protection Magazine, is an OSHA VPP site for safety, has received multiple awards from the National Pollution Prevention Roundtable, and has been recognized by the U.S. Environmental Protection Agency and Keep America Beautiful.”