Rink

What type of refrigeration plant do you have? This is the first question to ask as many rink operators may not be sure what type of refrigeration plant is in their building. While it might seem like it's OK not to know your system because someone else takes care of the maintenance, it is impor- tant to understand how things works in order to talk to service contractors intelli- gently. If you don't have a basic under- standing of how things work, you are leav- ing yourself exposed to potentially being taken advantage of when it comes to serv- ice and repairs. Some of the basic information you need to know about your system includes: Is your ice plant a direct system or an indirect system? Direct systems only use primary refrig- erant to cool the rink floor and have a large amount of this refrigerant, somewhere between 3,000-5,000 pounds per rink. Freon would be the only refrigerant used in this type of system. Indirect systems use both a primary and secondary refrigerant. The primary refrigerant will remain in the ice plant and condenser. The secondary refrigerant will be circulated between the ice plant and the rink floor. This is the most common sys- tem used in the U.S. What type of primary refrigerant does your system use? The two main types of primary refrig- erants used in ice arenas are fre- ons and ammonia. The primary refrigerant is the substance that removes the heat and will be in a liquid state. As it picks up heat it boils and changes to a vapor/gas which takes the heat and goes through the compressor and ultimately out to the con- denser that rejects the heat outside the building. You should also know what type of freon you have (R22 or R134A, etc.) if that is your primary refrigerant. What type of secondary refrigerant does your system use? The two main types of secondary refrigerant are salt brine (calcium chloride) and glycol (ethylene or propylene). The secondary refrigerant is the substance that removes the heat by not changing state. The secondary refrigerant will remain in a liquid state as it is pumped through the pipes in the rink floor and returns to the chiller (evaporator) in the compressor room. In rare cases you may find methanol used as a secondary refrigerant. What type of condenser does your system use? Evaporative condensers are the most common type used in ice arenas. This type of condenser uses air and water to cool the hot gas in the pipes running through the condenser. This also requires that the sys- tem have enough primary refrigerants to be piped out of the building to the evapo- rative condenser. Water-cooled condensers will work in combi- nation with a cooling tower to allow water to run between the tower and condenser. This system keeps the primary refrigerant in the compressor room where a smaller amount of primary refrigerant is needed. Only water is piped out of the building and cir- culated between the water-cooled condens- er and the cooling tower. Air-cooled condensers are primarily used in northern U.S. locations and also with seasonal rinks, due to their limited capacity to cool in hot temperatures. These condensers are located outside and will have the hot gas primary refrigerant piped out to them. These look like large, flat aluminum beds with lots of fans run- ning on top of them. What type of compressors do you have? The most common type of compressor used in ice rinks is the reciprocating com- pressor. This compressor works much like a car engine with pistons and valves doing the work.Like a car engine, it requires reg- ular maintenance to operate efficiently. We are seeing more screw compressors being used in the rink industry lately and, since they are more efficient and require less regular maintenance, this trend should continue. With geo-thermal systems, scroll com- pressors are being used for rink refrigera- RINK REFRIGERATION 101 52 R INK MAGAZ INE may/june 2010 STARrinks.com How TO: part 3 of 6 This year RINK Magazine will discuss refrigeration in an educational 6-part series written by Dave Wescott. This information can be shared with your staff to promote some good discussion and possibly even enhance the ability of your operations staff. We encourage you to share your comments, ideas and repairs related to rink refrigeration systems by sending them along with pictures to davew@starrinks.com.

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