Janesville20.7°

Renovated ice arena, innovative ice system near completion

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Marcia Nelesen
September 5, 2012

— When the newly renovated Janesville Ice Arena opens—planned for sometime before Friday, Sept. 21—it will make ice with an innovative system that's probably the only one of its kind in North America, if not the world.

The ice arena was closed this summer so the city could replace its aged ice-making system. The $2.5 million project also includes a new roof, a new a locker room and a new storage room for the Zamboni ice-cleaning machine.

Bill Scherer, ice arena manager, had hoped to have the arena open for the Janesville Jets exhibition game Friday, but the sealer on the concrete slab beneath the ice appears to be slowing the freezing process, Scherer said. The game instead will be held at the Oregon Community Ice Center.

Scherer expects the rink to be ready for the Jets' first regular-season game Friday, Sept. 21. The delay will allow finishing touches, Scherer said. The Jets players, for instance, offered to paint the bleachers, and the figure skaters are painting the warming room.

The rink's new ice-making system uses a geothermal heat pump. That's not unique. A Michigan ice rink, for example, dissipates and generates heat with a geothermal system using wells drilled into the ground.

Janesville's system, though, uses nearby Lions Pond.

"That we know of, there is no other geothermal ice hockey rink that uses a pond loop or a water body as its method of cooling and heating the system," said Joe Stadelman, vice president at Angus Young Associates.

Gary Grossman of Thermo Source, the system's manufacturer, came up with the idea after city staff visited his booth at a trade show. He found an aerial shot of the arena and noted the nearby pond.

The system consists of three loops of pipe—a hot loop, a warm loop and a cold loop—and a heat pump that transfers heat.

The cold loop runs between the heat pump and the ice slab. The warm loop runs under the concrete slab and to the pond. The hot loop feeds hot water to the Zamboni machine and the building plumbing, Stadelman said.

The pond loop includes 32,000 linear feet secured to the bottom of Lions Pond, about 17 feet below the water's surface. The pond water warms or cools the water inside the piping, depending on the temperature of the water, Stadelman said.

The water is continuously circulated from the pond to the arena, where a heat pump transfers the heat.

Piping from the heat pump is embedded in the rink's concrete slab to keep rink water on top of the slab frozen. Water in the cold loop contains glycol to prevent water in the pipes from freezing,

The waste heat from the pump is used to create hot water for the Zamboni, which requires water heated to 140 degrees. The hot water also is used to melt ice shavings from the Zamboni machine in the ice melt pit.

Waste heat also is used in a sub-floor warming loop below the frozen concrete slab to keep the ground beneath from freezing and heaving.

The system was about $120,000 more expensive than the standard ammonia-based system that creates ice, but the city will recover the extra expense in about 7˝ years through lower operating costs, Stadelman said.

The payback could come sooner because Stadelman expects energy costs to continue to rise.

Stadelman estimates annual savings in electricity, water and maintenance at about $21,000 annually, which will mean "significant energy and maintenance savings over its life."

The company calculates a 40-year life for the mechanical equipment. The plastic piping will last longer because it is not expected to degrade, Stadelman said.

The system also is safer, Grossman said. Ammonia in its concentrated form is toxic and can be dangerous if not handled correctly. An ammonia-based system also requires specialized maintenance.

Janesville's system is safe and can be maintained by city staff, he said.

Janesville's system also saves water, Grossman said. An ammonia-based system relies on an evaporative condenser that uses at least one million gallons of water per year per sheet of ice, he said.

"Evaporative condensers are noisy, leak-prone and expensive to repair," he said. "This system operates on a much simpler principle and will mean less repair.

"What we've done, by using the pond loop, is eliminate the evaporative condenser," he said.



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