Snozone Milton Keynes
Snozone provide the UK’s leading snow centres for indoor skiing and snowboarding on real snow. Snozone’s two indoor snow centres, located in Milton Keynes and Castleford, offer skiers and snowboarders an authentic slope experience. The facilities suit first time skiers or experienced snowboarders, and have taught nearly 2 million guests since opening in 2000. The facility in Milton Keynes has a run 170m long is maintained at -4C air temperature and contains 1500 tonnes of Snow and Ice. The cooling system provides low temperature glycol for circulation in pipework under the slope, to air coolers in the room and snow guns to maintain the Alpine environment for the customers enjoying their winter sports. The facility is also an anchor tenant in the purpose built Xscape leisure and retail complex and is a key attraction in Milton Keynes which celebrated its 50 year inauguration in 2017. Snozone contacted M&E Building Services Consulting Engineer, Hulley & Kirkwood, to help them with problems they were experiencing with the refrigeration system. In recent years the plant was becoming more unreliable and was having difficulty coping with Summer ambient temperatures. This resulted in problems with maintaining temperatures in the snow chamber and meant that temporary chiller plant was required on a seasonal basis to augment cooling from the R404A chillers installed in 1999. The striking architectural line of the Xscape roof structure mean that all building services were located inside the building with air intakes/ outlets taken through the perimeter walls. The plant comprised 2 x 100% primary circuits with screw compressors and shell and tube evaporators inside the machinery room. Heat rejection equipment comprised air cooled condensers located in a dedicated chamber and air blast oil coolers also in the plant room. The secondary refrigerant system pumps glycol through the chillers to 16 coolers mounted in the roof of the ski slope and to the underfloor pipe grid. The screw chillers were rated for 360kW at -16C glycol off temperatures. As the original manufacturer, Tri-Therm are no longer in business the plant was being maintained by a local contractor. For this reason, it was difficult to obtain information about the plant so site surveys and some original drawings provided some background data. The customer decided to invest in a future-proof, brand new refrigeration plant and since they had good experience using ammonia at their other location in Castleford, they sought to use this refrigerant at Milton Keynes. The existing plant room was unsuitable to retrofit a new ammonia plant so the decision was taken to locate the new system outside. A site survey revealed that it was impractical and costly to install the chillers in the car park so a location was chosen on the public thoroughfare outside the existing plant room. This location offered short tie in connections for power and glycol but also allowed improved airflow for the new chillers and the ability to create a secure compound. It was recognised early in the project that it would be necessary to engage a specialist consultant to conduct an Ammonia Hazard Assessment to identify all safety measures required for installation of the new outdoor refrigeration system. Star Technical Solutions (STS) attended site and specified a number of project enhancements for the safety of building employees and the general public.
- Secure compound which did not obstruct fire exit stairway
- Relief valves piped to a dispersion tank sized to absorb any ammonia releases
- Ammonia gas detection sensors on both chillers tie back to a building alarm system
- Alarms to isolate air intakes in the vicinity of the chillers
- Delivery of ammonia awareness training to Snozone staff
Snozone Milton Keynes