World Curling Federation cites CO₂ as only refrigerant

On 1 August 2018, the World Curling Federation (WCF) launched a new guide to ‘Curling Ice and Arena Requirements for Olympic and World Curling Federation Competitions’, citing only natural refrigerant CO₂.

The new guide – which replaced a 2014 edition – states, “for environmental and safety reasons a direct expansion system must use an environmentally friendly and safe refrigerant, as for example CO₂.”

Why CO2?

R744.com contacted the WCF to know more about why they cite CO₂ technology over ammonia or other refrigerants. “To answer your enquiry, CO₂ is mentioned as an example of a good system,” a spokesperson at the WCF stated. 

Jörgen Rogstam, managing director at ice arena specialists EKA (Energi & Kylanalys), which designed many of the CO₂ ice rinks currently in operation in Sweden, explains that this does not necessarily rule out other refrigerants from being used in curling rinks – including another natural refrigerant, ammonia.

“[The] phrase refers to direct expansion only, and in such an application, ammonia will never be permitted,” Rogstam said. “As [a] primary refrigerant in combination with a secondary refrigerant, ammonia may be [used], although the WCF does not mention ammonia specifically.”

“Curling sheets are seldom built […] in Europe anyway, so the business is small,” he explains, “[EKA] has designed indirect systems (pump-circulated CO₂) for curling in Norway, but in those cases in combination with ammonia as primary refrigerant.”

EKA is currently designing its first CO₂ direct expansion system, which will be installed in a curling and hockey rink in the Nordic countries with support from refrigeration system contractor Bravida Cooling – according to a LinkedIn post on LinkedIn by Rogstam.

The ice and events arena in Gällivare, northern Sweden will be a direct CO₂ refrigeration system with two-stage heat recovery for heating the ice. “Due to the cold climate, geothermal storage is connected to the refrigeration system serving as an additional heat source for the heat pump/refrigeration system in winter,” Rogstam said. “During warmer periods the geothermal storage is recharged with sub-cooling heat from the CO₂ system.”