Prefab Chiller Offers Space-Saving Cooling
The Stellar Group, a Jacksonville, Fla., MCCP fabricator, offered a turnkey approach that appealed to Martek's management. Stellar's use of two MAXEâ„¢ centrifugal chillers (equipped with the OptiSpeedâ„¢ variable-speed control) enabled Martek to increase the tonnage of its chiller plant capacity by 60 percent using half the space.
By using variable-speed drives on the chiller, as well as the primary chilled water and condenser water pumps, Martek was able to achieve optimal system efficiency. It is estimated that energy savings will be greater than 25 percent over the aging ammonia equipment system, due to the new chillers and the use of the drives. (Editor's note: For proprietary reasons, Martek cannot specify the total tons of refrigeration at this manufacturing location, nor the total dollars spent on the chiller plant expansion and upgrade.)
REAL VALUEAccording to Martek executive vice president Paul Kelley, "The real value of a modular central chiller plant is that the manufacturer of the plant takes responsibility for the design as well as the installation, startup, performance, and in our case, the maintenance of the plant. In this particular project, we did not use the services of an engineering firm, and while the plant manufacturer addressed the chilled water issues, we continued to focus on our production process."
Martek researches and develops products derived from microalgae. The company has developed and patented two fermentable strains of microalgae that produce oils used primarily in infant formulas. At the time of the chiller plant's planned replacement, the Winchester facility was running at a high level of production.
"There was a concern that any new construction not be invasive on the production process," said David Welsch, senior project coordinator. "I have to say that the installation of the modular chiller plant was one of the smoothest construction projects I've seen of this type."
Savings to Martek were significant in terms of both time and costs. "We wrote a purchase order for the modular central chiller plant in December, broke ground the second week of February, and had the plant online April 14 of last year. The actual design process took approximately six weeks, as compared to the average six months for a stick-built plant."
COST SAVINGSWells cited savings of at least 15 percent as a result of the company's decision to install an MCCP. The system's smaller footprint also allows Martek room for future expansion in a facility described by management as "very tight."
Because the MCCP was not being assembled on site, coordination was critical between activities in the field and those at the equipment's manufacturer. To ease the concern that field measurements match those of the MCCP, the equipment manufacturer placed an area service manager onsite for the duration of the job to pay close attention to details and facilitate an ongoing dialog between the construction site and the module manufacturer.
"The evolution of the modular central chiller plant resembles the evolution of the chiller itself," stated Kurt M. Liebendorfer, senior vice president, The Stellar Group. "Some contractors will remember the days when large-tonnage chillers were engineered and erected in the field. Condensers, heat exchangers, and compressors were specified, delivered, installed, and piped together.
"Today, the vast majority of chillers are packaged by the original manufacturer, with the main components - motor, compressor, heat exchangers, starter, and controls - integrated, tested, and shipped as a unit."
That same thinking is now being applied to the entire chiller plant, Liebendorfer said. Fabricators like Stellar pre-engineer all the central plant equipment (chillers, pumps, cooling towers, starters, controls) that is traditionally shipped to a jobsite as individual components. These specialized fabricators package the equipment in an enclosed skid that is prepiped, prewired, tested, and shipped to the jobsite as a module. After the module is placed onsite, only water and power connections need to be made.
For more information, visit www.thestellargroup.com.
Publication date: 05/29/2006