By: Brendan Lenko, P.E. Ice skating rinks have for a long time been a popular form of winter recreation. Recent American success in hockey and figure skating at both the international and Olympic levels has resulted in an ever increasing interest in ice sports and an equal demand for ice time. Existing ice rink facilities are being pushed to operate for longer seasons and new facilities are opening for 12 month seasons to satisfy the needs for ice. While ice rinks are already one of the most energy intensive forms of recreation, adding ice surfaces and lengthening ice seasons will only add to energy costs for ice rink operation. The following is a list of ten useful ways to conserve energy and operating dollars in any ice rink facility. Back to Top 1. Low Emissivity Ceilings Low emissivity ceilings are an automatic first choice for energy savings in almost any ice skating rink, especially for rinks operating in summer months. These suspended ceilings are actually foil faced radiant barriers. They nearly eliminate the radiant heat load in an ice rink that typically represents 25-40% of the overall refrigeration load. This radiant heat load naturally occurs when a large ice surface directly faces a large relatively warmer ceiling surface. Low emissivity ceilings, then, can reduce this load by up to 95%. This represents a reduction in annual refrigeration energy costs by 20-35%. Depending on the local climate, operating season and electricity rates, the energy savings with the installation of a low emissivity ceiling will range from $6,000 to $18,000 per year. With installed costs of approximately $25,000/year, financial paybacks of less than 3 years can often be expected. Back to Top 2. Ice Temperature Controls A one degree (1 F) increase in ice temperature will save approximately 6% annually in refrigeration energy costs. Most ice rink refrigeration control systems control the temperature of the slab, or brine / glycol temperature below - not the ice. They are typically set to keep things cold 24 hours a day whether the ice needs it or not. As a result, much more energy is used than necessary. Installing a control system that controls the actual ice temperature will prevent this unnecessary over cooling. Such ice temperature control systems can also be used to raise the ice temperature up at night and unoccupied periods for even more energy savings. With an ice temperature control system, energy savings from 5-15% can be expected. In a typical rink this can amount to $3,000-$10,000 annually. With an installed costs of between $5,000-$15,000, extremely good financial paybacks are possible. Back to Top 3. Pump Controls A 30 hp brine or glycol circulation pump, when running constantly running will cost $8,000-$10,000 per year in electrical operating costs (based on electricity @$0.06/kWh). Incorporating a pump control system that reduces or stops the brine pump operation under part load or non refrigerating conditions can save $1,000-$6,000 per year in electrical costs. This results form both the reduced pump motor operation and the reduced need to refrigerate the heat generated by pumping friction. The cost of such equipment varies from $2,500-$20,000 depending on the specific equipment used. Such costs can be reduced when a pump control system is installed together with an ice temperature control system. Back to Top 4. Ice Maintenance Proper ice maintenance costs very little compared to the extreme energy costs that occur when ice is not properly maintained. For example, carrying ice at 2" thick will cost approximately 10-15% more in refrigeration costs compared to carrying ice at 1" thick. A regular ice maintenance program can help prevent ice from building up and causing higher energy costs. 5. Space Heating Heating the air in an ice rink can be quite expensive to operate. Not only does it require energy to heat the entire volume of air in the ice rink area, but it also creates a higher convective heat load on the ice which must be removed by the refrigeration system. One useful alternative to heating the ice rink space is by installing infrared radiant heaters. These long tubular heaters effectively heat the people in the stands by radiation without directly heating the air in the ice rink area. As a result, the heating costs are reduced and the convective heat load on the ice is drastically reduced since the air in contact with the ice is much cooler. The energy savings associated with this type of heater varies with the amount of time the heaters are actually used. The refrigeration energy savings possible with this type of equipment range from 3-12% annually. Back to Top 6. Waste Heat Recovery for Snow Melting or DHW Using condenser heat to preheat domestic hot water or for snow melting can certainly reduce the heating costs for water. Rinks that use electricity for water heating should certainly consider this option if natural gas is not available. Although the installed costs of this type of heat recovery vary with the refrigeration system design and building layout, they should always be considered in planning any new ice rink project. 7. Dehumidification Good dehumidification is important for any rink to prevent fog, condensation and dripping, especially if operating the ice surface in summer months. This drying of the rink air also serves to reduce the convective heat load on the ice. That is, the refrigeration system will have to do less work if the air circulating in the rink is dryer. Of course, mechanically dehumidifying the air also costs money to operate. The least costly way to dehumidify ice rink air is by using a desiccant type dehumidifier. This type of system consumes natural gas in the dehumidification process. Desiccant dehumidifiers should always be considered when planning for ice rink dehumidification. Back to Top 8. Air Handling Air movement over the ice surface also drastically increases the convective heat load on the ice. This heat load increases with any increase is air speed over the ice surface. If the ice rink uses any type of mechanical air handling system, ensure that the air movement is not directed toward the ice. Although some air circulation above the ice is permissible, it is estimated that the refrigeration costs can be increased by up to 25% with excessive air movement in the rink. 9. Flood Water Purification Incorporating a flood water purification system for ice making can save up to 10% in annual refrigeration costs. Although such systems are not typically installed solely for energy conservation purposes, facilities with high mineral content in their source water can benefit twice with such a product. First, they can improve their ice quality by using pure water which makes harder, faster and clearer ice. Second, the denser ice sheet will be able to transfer heat more easily to the ice made from mineral laden water. This will result allow slightly higher refrigerant temperatures to be used. Back to Top 10. Compressor Demand Limiting Controls If the local electricity rates incorporate a high electrical kW demand charge, it will be useful to investigate the possibility of limiting the number of compressors that operate at any one time. For example, in winter months it may be possible to operate the ice with one less compressor and reduce the peak electrical demand for that month. This type of control is typically applied in multiple compressor installations where the original compressor controls are set to operate all of the compressors with a call for cooling. With relatively little initial capital cost, savings up to $500 per month may be possible. About the Author: Brendan Lenko, P.E. is a professional engineer and President of Energy Ice. Through his career, he has been involved in hundreds of low emissivity ceiling projects through out the world in consulting, design, energy analysis and project management capacities. His experience includes projects in countries such as Japan, Russia, Finland, Sweden, Norway, Denmark, Switzerland, Germany, Indonesia, as well as Canada and the USA. If you have questions relating to low emissivity ceilings, ice temperature controls or just energy conservation & engineering in ice rinks in general, you can reach him in Canada at 905-632-8840. Back to Top |
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