Bahcohallen – New refrigeration system

Client:
Enköpings kommun

City:
Enköping

Year:
2015

Facility type:
Spectator B ice rink

Work category:
Design, CO2, CO2, Heat export, Heat recovery, Refrigeration, Rink floor, Sec. refrigerant

Bahcohallen used to be a typical single sheet ice rink, with a heated arena room (around 8°C). An ammonia refrigeration unit was connected to a brine circuit in the rink floor. A heat recovery function provided up to 28°C for the preheating in the air handling unit. In 2016 a new CO2 system was installed to replace ammonia, with direct expansion into new copper pipes that were laid in a layer of concrete above the existing rink floor. Furthermore, an additional ice sheet in a heated arena room (around 10°C) located in a brand-new building adjacent to the existing ice rink completes the facility in the 2017/2018 season. An optimized heat recovery system connected to the CO2 system is designed to cover a large part of the heating demands in both ice rinks.

The new refrigeration unit and its heat recovery function had reduced the energy consumption by 15% – from 4.72 to 4.00 MWh/day of activity – when Bahcohallen had only one ice sheet. At this moment the heat recovery function was not used at its full capacity yet. When the new ice sheet was connected to the unit for the season 2017-2018 – see Enköping ny ishall – the energy savings potential of the new system solution became more clearly visible. The CO₂ system is now able to run two ice sheets with an energy consumption that is only 23% higher than what the previous ammonia system needed when running one ice sheet.