Facility Profile - September 2007
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Skating in the Shadow of Palm Trees

Downtown Ice in San Jose, Calif.

By Peter Hercky


"I try to never walk away from a challenge," Clayton said. "Especially one faced by a good, loyal customer such as the Downtown Association."

Clayton turned that challenge over to his engineers and technicians who, after determining that the roof of the garage could withstand the added weight, came up with the solutions.

Ice Rink Events redesigned the rink floor piping system, whose classic makeup consists of a chiller connected to a header manifold from which smaller diameter pipes extend to cover the surface of the rink. The initial design called for the manifold to be located in the center of the rink, but it soon became evident that a semi-circular header along an arc would provide more reliable results.

"A local staging contractor build a 2-foot-high steel and wood platform deck to create a level stage," said Don "Scooter" Mosher, senior technical director for Ice Rink Events. "Before unfurling the tubing system, we lined the deck with insulation and then covered that with plastic sheeting."

The prefabricated, 16-mile long tubing system is made up of a series of 25-modular units, or "mats," configured to be unrolled and re-rolled as needed, with each mat custom-made. "The system is quick to set up," Clayton noted. "No on-site fabrication or welding is required."

After the ice mats are rolled out and connected to the refrigeration unit, they are filled with the coolant solution (propylene glycol, a non-hazardous anti-freeze.) Main headers are curved to match the outside of the 120-foot-diameter circle, and interconnected using groove lock connectors. This technique allowed for quick assembly and leak-free flow of the coolant solution to and from the refrigeration unit or chiller, as it is called in the industry.

An added benefit of the mat system is that it provides a high flow-rate of the refrigerant solution, and close spacing of each tube. These features not only cause the ice to freeze faster, but also enable it to remain frozen in most any climate.

"Traditional 1-inch polyethylene piping is spaced farther apart and therefore can't provide effective heat transfer for projects like this," Clayton said.

Two 150-ton air-cooled refrigeration systems, linked together, are permanently situated atop the Art Museum. They constantly circulate the 800 gallons of secondary coolant, leaving the chiller at 5 degrees Fahrenheit. As the ice mats are cooled, water is sprayed on to the rink. Within hours, ice completely covers the mats and soon, a perfectly uniform sheet of ice is formed. The ice is painted bright white, logos are applied, and the rink is ready for skating.

For a fee of $14 for adults and $12 for kids (skate rental included), nearly 40,000 San Joseans (200 maximum at any one time) are able to experience the joys of skating on real ice in the morning and still go for a dip in the Pacific in the afternoon. The 8,100-square-foot rink also serves as a stage for performance skaters who entertain the visiting crowds. A tractor-mounted ice resurfacing machine manicures the ice several times each day.

In mid-January, the entire rink is disassembled. The tubing mats, platform and chillers are stored in warehouses for safekeeping and re-use the following year.

"My sense is that the ice rink is a real traffic booster for the downtown area during the year's most active buying season," Schneider said. "Because we're living in a temperate climate, being able to enjoy a spin on real ice makes the holiday season that much more festive. We're pleased and proud to be a part it all."


FOR MORE INFORMATION

San Jose Downtown Association:
www.sjdowntown.com

Ice Rink Events:
www.icerinkevents.com

CALMAC Manufacturing Corporation:
www.calmac.com