<p>Today most ice rinks in Sweden use secondary refrigeration systems with a solution of calcium chloride and water as secondary refrigerant. Due to the large amount of energy such a system uses more efficient systems would be desired.An earlier study concluded in the possibilities of using carbon dioxide as secondary refrigerant with copper tubes as the loops in the ice rink. Since then 3 ice rink refrigeration systems has been built with carbon dioxide in copper tubes. Excluding the ones being direct involved in those projects there is still very little knowledge about how these system works. This study has been made primarily with the aim of adding to the knowledge concerning availability and cost and secondary to look at possibilities for improvement.A comparison between systems with carbon dioxide, calcium chloride respective ammonium solved in water has been made by using Decision Matrix. The comparison indicates that carbon dioxide is the more appropriate successor for the calcium chloride solvent.By using carbon dioxide the pump energy can be reduced considerably. With carbon dioxide there is also potential to use self circulation most of the time, and by doing so reduce the energy consumption even more.One area where knowledge seems to be lacking with carbon dioxide systems is in the ranges and availabilities of the required components. This study has shown that even if the ranges in some cases are limited it is still considerably easy to find suitable components. The price estimation made in this study estimates the total sum of the components for a carbon dioxide system at a bit over 900 000 SEK and a bit over 600 000 SEK for a system using calcium chloride. These numbers are mainly excluding costs for pipes and work.The second area where more knowledge seems to be needed is about ensuring the safety of the public while using carbon dioxide systems. The largest risk seems to be in the relatively high pressure of 3 MPa. But by using a good control system and having safety valves in all the critical spots there shouldn’t be any real risk for accidents. The risk for leakages is relatively easily countered by installing an alarm system with detectors for carbon dioxide. The large space inside an indoor ice rink also helps negotiating any leakage of carbon dioxide to the extent of possibly making it totally harmless even if undetected.</p><p> </p>

Today most ice rinks in Sweden use secondary refrigeration systems with a solution of calcium chloride and water as secondary refrigerant. Due to the large amount of energy such a system uses more efficient systems would be desired.An earlier study concluded in the possibilities of using carbon dioxide as secondary refrigerant with copper tubes as the loops in the ice rink. Since then 3 ice rink refrigeration systems has been built with carbon dioxide in copper tubes. Excluding the ones being direct involved in those projects there is still very little knowledge about how these system works. This study has been made primarily with the aim of adding to the knowledge concerning availability and cost and secondary to look at possibilities for improvement.A comparison between systems with carbon dioxide, calcium chloride respective ammonium solved in water has been made by using Decision Matrix. The comparison indicates that carbon dioxide is the more appropriate successor for the calcium chloride solvent.By using carbon dioxide the pump energy can be reduced considerably. With carbon dioxide there is also potential to use self circulation most of the time, and by doing so reduce the energy consumption even more.One area where knowledge seems to be lacking with carbon dioxide systems is in the ranges and availabilities of the required components. This study has shown that even if the ranges in some cases are limited it is still considerably easy to find suitable components. The price estimation made in this study estimates the total sum of the components for a carbon dioxide system at a bit over 900 000 SEK and a bit over 600 000 SEK for a system using calcium chloride. These numbers are mainly excluding costs for pipes and work.The second area where more knowledge seems to be needed is about ensuring the safety of the public while using carbon dioxide systems. The largest risk seems to be in the relatively high pressure of 3 MPa. But by using a good control system and having safety valves in all the critical spots there shouldn’t be any real risk for accidents. The risk for leakages is relatively easily countered by installing an alarm system with detectors for carbon dioxide. The large space inside an indoor ice rink also helps negotiating any leakage of carbon dioxide to the extent of possibly making it totally harmless even if undetected.