Dean,  I thought you would like to see the news about R22 from Cloquet.  As I understand there will be another in-depth story coming out soon.  I will be sure to forward it to you.   Thanks,  John Evans

                        Fox TV 21


 Northwoods Arena aging well, but cooling system will be obsolete soon

Jana Peterson

Architect Chuck Freiberg told the Cloquet City Council he fell in love with the city’s Northwoods Credit Union Arena, adding that it wasn’t easy to find anything major wrong with the 17-year-old facility.

Engineer Scott Ward told them the ice system — the floor system is the same age and the refrigeration system is 25 years old — is one of the most efficient systems ever designed.

Then he told them that the refrigerant that powers that system (R22) will no longer be available in 2020, because it is harmful to the ozone layer and contributes to global warming.

Ward and Freiberg were hired by the city and the Cloquet Area Hockey Association to evaluate Northwoods Arena and presented their findings at the Council’s formal meeting on Tuesday. While the pair of consultants had numerous suggestions for improving the facility, the report was mostly positive … except for the problem of cooling the ice.

“We’ve seen [refrigeration systems] like yours run 40 years,” said Ward, who works for Stevens Engineering, Inc. “It’s a great system. But R22 makes it obsolete.”

Northwoods is not the only arena in Minnesota still using R22 as a coolant. And, while R22 will no longer be available in North America after 2020, the city and hockey association could theoretically continue to use R22 to cool the system as long as they have a sufficient stockpile of R22 and the system holds up (meaning there are no breaks resulting in a release of the ozone depleting chemical). Cost of R22 — which has increased in price 850 percent since 2005 — is expected to continue to rise as the chemical is phased out by the Environmental Protection Agency (as part of the Clean Air Act) over the next six years.

After Ward explained that changing the refrigeration system could mean digging up the floor of the arena and more, Councilor Dave Bjerkness asked if there was any alternative coolant that could be used in the existing structure.

Ward said carbon dioxide (CO2), which is a naturally occurring refrigerant, could be a possibility in the future and might mean less dramatic changes to the system, although current designs call for larger pipe sizes in the floor and a different header sizes at each end of the floor. An arena in Montreal, Canada, installed a direct system using CO2 during the past year, according to the consultants’ report, which suggested CO2 will likely be the next “innovation” in the ice rink industry.

Along with CO2, ammonia is another naturally occurring refrigerant being used in European countries, which phased out R22 in 2000. 

The consultants did not push the Council to immediately embark on a plan to change the cooling system, in part because new designs keep being developed.

“We recommend you try to keep the facility running as long as you can,” Ward said, estimating the refrigeration system as a whole could be good for another five to 15 years. “If you can keep it tight — meaning no R22 leaks — it should run fine.”

The report offered seven options for the ice system, ranging  from doing nothing except maintaining the existing system (estimated cost $231,000) to creating a new indirect system (using ammonia) sized for future connection to Pine Valley Ice Arena at an estimated cost of $1.94 million plus another $843,000 to actually hook it up to Pine Valley (aka The Barn). The most expensive option was converting to CO2 for both facilities, which was estimated at close to $3 million.

Other suggested improvements

Locker room amenities were near the top of the list for suggested improvements, including toilet facilities and showers. Space for visiting teams — especially the junior hockey teams — to leave equipment overnight is also needed.

Humidity is an issue in the summer, and changing the lights to LED lights would cost a lot up front, but save another 25 percent in energy costs over the existing fluorescent lights (which already save 40 percent over the previous lighting system). Freiberg also suggested building an indoor snowmelt pit and putting concrete dividers outside the side doors to stop snow from piling up there.

The roof should also be evaluated, because it is 17 years old. When it’s time, Freiberg suggested replacing the roof with a UV-resistant material, which reflects UV rays that penetrate older roofs and cause the ice to melt (or the cooling system to work harder).

“You’ve got a beautiful facility, she needs a little help so she can meet people’s expectations,” Freiberg said, marveling later at the “engineering feat” required to build the arena on what was essentially swamp land. “Beautiful sight lines, I’m sure you know that.”

The consultants did not evaluate Pine Valley, but they did walk through the neighboring arena, which is reputed to “be the coldest arena in the state,” Freiberg said, not disagreeing with that assessment.

Mayor Bruce Algren thanked the two consultants for their compliments on the arena, noting that he was heavily involved in the efforts to build it.

“You wouldn’t see a facility built like that today,” Ward responded. “It’s very nice.”

R22 Refrigerant Story From Cloquet