New “green” ice rinks glide into operation thanks to ammonia

Aware of the environmental impacts of HFCs and in order to comply with new regulations designed to phase down the HFCs, hundreds of ice rinks have decided to replace their existing R22 systems with ammonia (NH₃). Not only is NH₃ an environmentally friendly refrigerant (GWP=0) it is also far less expensive than other refrigerants and offers higher efficiency and significant energy savings.

Comparative study reveals the high performance of ammonia-based refrigeration systems

A techno-commercial study conducted by the Natural Resources Canada’s CanmetENERGY Research Centre has analysed the performance of the 12 most typical refrigeration systems used at ice rink facilities in Québec. Compiled results in 425 sport sites show that ammonia refrigeration systems are more efficient and use less energy if compared with R22 refrigeration systems.

• Coefficient Of Performance (COP): On average, the COP of an ammonia refrigeration system is 3.0, whilst a system working with R22 has a COP of 1.6.
• Total energy consumption: The total energy consumption of an ammonia system is about 525 mWh/year on average, whilst an R22 system consumes up to 1,020 MWh/year.
• Electric power demand: For ammonia systems, the maximum electric power demand is about 194 kW on average. However, the power demand for R22 systems reaches 381 kW.

Success stories

Some examples of ice rinks equipped with an ammonia refrigeration systems include:

• Bursville Ice Arena, U.S. – In December 2012, the city of Burnsville, U.S., upgraded the city ice skating facility with an ammonia refrigeration system. This technology has enabled annual energy use reductions of 43% as compared to the former obsolete system. The facility’s overall carbon emissions have also been reduced by 20%.

• Dewars Centre, UK - Live Active Leisure (LAL), a UK-based leisure company active for nearly 40 years, replaced an existing R22 system at its ice rink site with an air-cooled ammonia chiller complete with heat recovery in June 2014. The highly efficient system, which has an ammonia charge of just 0.3 kg/kW of refrigeration capacity, enables the chiller to still be efficient even at its minimum load of 10%.

• Daqing Speed Olympic Park, China - In September 2014, the first ice-training center using ammonia refrigerant opened its doors in Daquing, China. The project also entailed one of the largest ever sport refrigeration projects launched in Asia. With a capacity of 2860 kW, a cutting-edge system enables the monitoring of the refrigeration plant and its energy consumption, lighting control, the remote control of the heating, air conditioning, ventilation and dehumidification systems, and the monitoring of the ice thickness and hardness, as well as the ice surface temperature according to the different requirements of each event.

Innovation and training guarantee safety when using ammonia as a refrigerant

Although the main characteristics of ammonia are its penetrating smell and its toxicity, this refrigerant has a good safety record as technical failures and operational deficiencies are easily monitored and detected.

Ammonia systems should be designed, installed, operated and maintained in accordance with national safety standards and codes of practice. Moreover, national and international organisations such as the IIAR and the US EPA have released numerous reports and developed several programs centered the safe use of this refrigerant, providing key guidance on how to prevent the release of ammonia. Key recommendations include:

• Having a preventative maintenance program in place
• Having an ammonia detection system installed in the engine room and that triggers the onset of an independent ventilation system and alarm
• Having an emergency response plan

Business and industry leaders also play an active role in this matter, developing advanced refrigeration technologies and more sophisticated systems that prevent, monitor and quickly detect possible leaks. Training programmes designed for HVAC&R professionals when designing, manufacturing, installing or commissioning ammonia refrigeration systems are also key to mitigating risks.