Accent Refrigeration installs secondary loop using 12%-14% ammonia solution in Canada, improving efficiency.
Accent Refrigeration Systems, Victoria, B.C., last month installed a system using ammonia as the primary refrigerant and “aqua ammonia”(ammonium hydroxide) – a water solution consisting of 12%-14% ammonia – on the secondary side at the Chilliwack Curling Rink, Chilliwack, B.C.
It’s the first such use of aqua ammonia in North America, said Art Sutherland, president and CEO of ccent Refrigeration. In Sweden, there are 30 ice rinks where aqua ammonia is used, estimated Jörgen Rogstam, managing director, for Swedish ice arena designer EKA, in February.
The Chilliwack system uses two chillers, each with just 50 lbs of ammonia. With such a small amount of ammonia, a leak from one of the chillers would barely change the aqua ammonia solution. “You can do nothing with the aqua ammonia, and just fix the chiller,” said Sutherland.
Aqua ammonia is more a more efficient secondary refrigerant than brine, requiring a 5-HP pump vs. a 9.5-HP pump for calcium chloride. Aqua Ammonia uses just 45% of the pump power required by ethylene glycol, said Rogstam.
Another advantage is that it can be used with conventional polyethylene piping while CO2 requires more expensive stainless steel or copper pipes.
Aqua ammonia is caustic and needs to be used with goggles to protect the eyes. But Sutherland tested it on him arm for three minutes and, after washing it off, came away without a mark.