The athletics center boasts an Olympic-sized ice rink, and utilises a CO2 transcritical system to freeze the ice. It was one of the first in the U.S. to use a natural refrigerant cooling system.

Hillphoenix installed the highly efficient Advansor transcritical CO2 system. It is designed to capture excess heat that can be repurposed throughout the facility. The system at the McDonald Memorial Center uses a CO2 charge of 4,500 lbs. 

The closed-loop system works by pumping liquid CO2 under the ice first to freeze it, then to remove residual heat. When the liquid CO2 along with some vapour comes back, it goes into a separator vessel, where the gas is sent to the compressor to be liquefied before being pumped back under the ice again. The vapour also goes through an oil separation system to remove any oil.

Some of the heated vapour, as well as the heat removed from the ice, goes through a heat reclamation system to be used elsewhere in the arena, or rejected to the atmosphere.

Author r744