Circle of Palms
Learn about an outdoor ice skating rink in San Jose, California where the temperature ranges from an average of 50 degrees in January to approximately 70 degrees in July.

Project Facts
- 8,100 square foot rink
- 120-foot diameter circle plus a 12-foot wide outer circular track
- 16-mile long tubing system
- Outside air temperature ranges from an average of 50 degrees in January to approximately 70 degrees in July
- Ice remains frozen at 100° F (38°C)
- Download the case study.
OVERVIEW
Skating in the Shadow of Palm Trees
The downtown scene could be right out of a Christmas season Hollywood movie. It’s mid-December and shoppers are hurriedly wandering in and out of quaint and trendy shops, which have been appropriately adorned with festive holiday decorations. The Salvation Army Santa is joyously ringing his bell and in the background, one hears carols being sung by a choir. Approaching an open area the ice rink comes into view, complete with master skaters performing reverse figure-eights and novices holding on to the railing as they work to gain their ice-legs.
Were it not for the palm trees and the lightweight attire, this scene might easily be mistaken for New York, Chicago, Minneapolis or Boston. It is, in fact, San Jose, California where the temperature ranges from an average of 50 degrees in January to approximately 70 degrees in July. Not exactly ideal conditions for an ice rink.
“Our mission has always been to help the downtown merchants in attracting shoppers to the district, and an ice rink seemed like an attractive idea,” notes Scott Knies, Executive Director of the San Jose Downtown Association.
Yet, despite the temperatures, the citizens of San Jose have been donning ice skates for the past 14 years and taking part in a winter activity that’s generally reserved for those colder locales. Along with its unorthodox location, this rink is also unique in that it is erected just after Thanksgiving and dismantled by mid-January.
“No one seems to remember how the idea was developed,” notes Scott Knies, Executive Director of the San Jose Downtown Association. “Our mission has always been to help the downtown merchants in attracting shoppers to the district, and an ice rink seemed like an attractive idea.”
CHALLENGE
The San Jose Downtown Association (SJDA), which was founded in 1986, is a non-profit, membership-based organization. It represents business and property owners and it strives to enhance the vitality and livability of downtown San Jose.
Since its inception, the rink had been located in four or five venues including several parking lots and other open areas throughout the downtown area. Every few years the rink would need to be relocated because that previous year’s property was slated for development. “Although it complicated matters, we were happy to move the rink. After all, development is at the core of the Association’s mission,” notes Janis Schneider, the Association president.
With increasing development and fewer appropriate locations available for situating the rink, the Association turned to the Mayor’s Office for assistance. Then Mayor Ron Gonzales thought placing the rink at the Circle of Palms plaza would be a boon to the area, but he also believed that the logistical problems seemed insurmountable.
The plaza sits atop a four-story underground garage in a pristine area of the City. It’s surrounded by the Art Museum, the 5-star Fairmont Hotel and the world headquarters of the Knight Ridder Publishing Company. Thirty-two palm trees dot the perimeter of the Plaza and the Seal of the State of California is emblazoned in its center.
SOLUTION
The decision was made to permanently situate the “nomadic rink” at the Plaza in July of 2004. However, the rink needed to be in place and ready for use in time for the Thanksgiving holiday. That’s a five-month window to design, engineer, plan logistics, manufacture and install a project of this complexity and scope; a process that would normally require 12 months to complete. “We called Mike Clayton at Ice Rink Events to tell him about the ‘great’ news—a circular-shaped rink with 32 palm trees in the middle,” Knies said. “I remember a deafening silence on the other end.”
Ice Rink Events has been installing and dismantling San Jose’s winter rink for the prior six years. An Ice Rink Events crew begins the process sometime in the beginning of November and the first skaters take to the ice the day before Thanksgiving. The process consists of preparing the surface, rolling out and assembling the piping system, connecting the chiller and adding water.
RESULTS
Along with the shortened time frame for installation, the rink’s new location presented additional challenges. First, the rink shape was changed from the classic rectangular to a circle, actually two circles, one within the other. This radical change in shape demanded an entirely new line of thinking from Ice Rink Events with the traditional layout of the rink cooling floor now required to freeze a 120-foot diameter center circle, plus a 12-foot wide outer circular track.
Secondly, the rink was to be erected on an uneven plaza, with as much as a 2-foot change in elevation. Thirdly, luxury automobiles would be parked in the garage beneath the rink. Would ice melting and other water leakage pose a problem. Lastly, the rink had to be designed to accommodate four tree-areas with 8 palms in each area. “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 two foot high steel and wood platform deck to create a level stage,” states Don “Scooter” Mosher, Ice Rink Events’ Senior Technical Director. “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 by CALMAC Manufacturing Corporation of Fair Lawn, NJ. “Ice Rink Events picked CALMAC’s IceMatII® because the system is quick to set up,” notes Clayton. “No on-site fabrication or welding is required. The quality of their product is extremely high, as is CALMAC’s level of support.”
Clayton offers CALMAC IceMat® products exclusively to his customers. "We’ve been charged with the responsibility of building every kind of rink from a championship-quality NHL-sized ice rink, to a permanent rink with full dasher boards and a sand-base,” he said. “The only product able to do this job is the CALMAC’s IceMatII®, with an added plus-- it makes the best ice. There is no equal,” according to Clayton.
SUMMARY
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.
“My sense is that the ice rink is a real traffic booster for the downtown area during the year’s most active buying season. 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,” observes Janis Schneider, Association president.
An added benefit of the CALMAC IceMatII® 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 to enable it to remain frozen even when temperatures reach 90° – 100° F (32° – 38° C). “Traditional 1-inch polyethylene piping is spaced farther apart and therefore can’t provide effective heat transfer for projects like this,” Clayton says.
Two 150-ton Trane 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 F. 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 Olympia ice resurfacing machine manicures the ice several times each day.
In mid-January, the entire rink is disassembled. The tubing mats, platform and chiller 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,” observes Schneider. “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.”