Burnsville Ice Arena saves 43% on energy use with ammonia system

By Klara Skačanová, Jan 08, 2013, 12:16 2 minute reading

With the help of funding through the US Department of Energy, the city of Burnsville has invested $5 million (€3.81 million) in upgrading the city Ice Arena with an ammonia refrigeration system and additional energy saving features. The total annual energy use has been reduced by 43% as compared to the former obsolete system.

Prior to the renovation, the facility was one of the largest CO2 producers in Burnsville spending an average of $29,000 (€22,108) of city’s budget annually on compressor repairs.

With all the energy efficiency and conservation improvements at the Burnsville Ice Arena, it could become a model for aging ice arenas across the US, as well as cities considering projects to reduce their energy costs and environmental impact.

Ammonia system at heart of energy saving renovations

One of the renovations that resulted in substantial savings was a new industrial-grade ammonia refrigeration system. The system emits waste heat into the ice arena’s new geothermal-based HVAC system through a core water loop. The core water loop provides heat for the building and arena, as well as for subfloor heating, snow melting, domestic water, and dehumidification. The system also includes two cold water loops, which provide cooling for the HVAC system and pre-cooling of ventilation air entering the ice arenas. This balance between heating and cooling in the systems helps to save money and energy over the course of the year.

“We probably spent about 28 hours a year on labour on compressor repairs, now our staff can dedicate more time to general maintenance and keeping the ice arena at top quality for the best customer service,” said the project manager Dean Mulso.

As a result of the new refrigeration system the amount of refrigerant needed for operation has reduced from 10,000 pounds (around 4,536 kg) to only 600 pounds (272 kg) annually, thereby saving not only on energy costs, but also on the cost of refrigerant.

43% annual savings on energy use

The project has delivered a number of environmental and financial benefits. The new mechanical systems will recover and use 100% of the heat emitted from the refrigeration system, saving 78,000 therms (around 2,286 MWh) annually. Overall, annual energy costs of the facility’s entire operation will be reduced by an estimated $77,000 (€58,716) per year, with total annual energy use reduced by 43%. The facility’s overall carbon emissions were also reduced by 20%.

In addition to replacing the HVAC system, the $5 million project had a wide scope involving a number of different renovations throughout the facility, such as:
  • energy efficient lighting retrofits
  • energy management systems (EMS)
  • melting pit for ice shavings
  • energy efficient dehumidification system reducing the air-conditioning system load by 30-40%

About the project funding

The renovation project was initiated in 2010 after receiving an Energy Efficiency Conservation Block Grant (EECBG) of $347,000 (€264,421) through the U. S. Department of Energy as part of the American Recovery and Reinvestment Act (ARRA). The grant provided an impetus to initiate the project with the overall cost of $5 million (€3.81 million).

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By Klara Skačanová

Jan 08, 2013, 12:16




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