Aldrich Arena will get an estimated $3.6 million worth of renovations next year, as Ramsey County gets ready to phase out the use of Freon at its ice rinks and switch to a more available coolant.

The county also will repave the Maplewood arena's parking lot; upgrade its heating, ventilation and lighting systems; and bring the arena into full compliance with the Americans with Disabilities Act. The upgrades are expected to save the county an estimated $30,000 a year in energy costs, county spokesman John Siqveland said.

The work is expected to start in the spring and finish by Nov. 1, said Mark McCabe, county Parks and Recreation director. "We'll work around the existing schedule as much as possible to make sure there's no ice time closures."

Ramsey County has been wrestling with the future of its 13 sheets of ice, at 11 sites, for several years.

A task force found in 2016 that demand for ice time had been slipping at the county's arenas since the start of the Great Recession in 2007. The county's annual average of about 14,000 rental hours had fallen to about 10,000 hours by the 2011-12 season. But since 2016, demand has been steadily climbing.

The county already has rented out 16,500 hours of ice time for the upcoming 2018-19 season, McCabe said.

The most pressing question now is what to do with each arena's cooling system.

With manufacture of the gas R-22, or Freon, set to end in 2020, the task force recommended that Ramsey County slowly begin the expensive process of replacing its cooling systems with ones that use more environmentally friendly ammonia-based coolants.

The switch from R-22 will take years to implement at all the county's arenas. Expecting prices to sharply climb once the gas is out of production, Ramsey County stockpiled it to keep operating its obsolete systems into the foreseeable future, Siqveland said.

"We will also add excess R-22 from Aldrich and other facilities into that inventory as they are switched over to ammonia," he said.

Funding is in place to upgrade the county's ice arenas in Shoreview and White Bear Lake sometime in the near future, McCabe said.

"Before we make any capital investments we just want to make sure that the long-term feasibility is there," he said.

But Aldrich will be the first to get a new cooling system.

While it's not the county's busiest ice rink, it's the oldest and its 4,000 seats give it the most versatility, said Ryan Ries, project manager for the parks and rec department.

"It gets used for concerts and farmers markets, graduations and conventions," Ries said. "Student drivers even practice parallel parking in the parking lot. It touches a broad swath of the community."

The county may add a second sheet of ice to the arena sometime in the future, Ries said.

Aldrich Arena long has been home ice for Hill-Murray High School, which recently helped upgrade the arena's showers and locker rooms.

It also hosts section hockey playoff games every February.

Greg Stanley • 612-673-4882