The objective of this research was to investigate indoor snow production and the improvement of the current systems. In 2019, there were about 50 year-round indoor ski facilities worldwide (Skoblickaya and Sherement 2019). Despite this large number of indoor ski areas, there is little literature on the energy efficiency of indoor ski facilities, indoor snowmaking or the refrigeration systems used.

The reference system of this research work was the indoor ski hall “SNØ”, which is located near Oslo, Norway. In order to achieve good snow quality, the temperature in the ski hall must be lowered for the snow production. To reduce the energy consumption, a snow production system was designed and evaluated in which snow is produced in external towers. The basic idea of the external snow production towers is to keep the temperature of the hall constant without the need for cooling down the complete hall, while snow is produced.

External production towers and energy analysis

The designed snow production system consists of four external towers. The CO₂-based refrigeration system is centralized, see Figure 1. To facilitate the distribution of the snow, the production towers are placed at different locations around the main hall.

The external snow production towers are designed with a height of 10 meters. This height is not enough for the drops to freeze completely until they reach the ground. In order to increase the time for the droplets to freeze, the towers must be operated with an air counterflow. This would need to be further investigated to also determine the energy consumption of these fans and add it to the overall energy balance.

The evaluation of the energy efficiency showed that about 44 928 kWh of electricity can be saved per year if the external snow production towers are used compared to the snow production in the hall. These 44 928 kWh correspond to about 0.7 % of the total energy consumption of the indoor ski hall.

A problem that occurs with the relatively small external snow production towers is the increase in humidity during snow production. This leads to a faster formation of frost on the evaporators, which has a negative effect on energy efficiency. An overview of defrosting methods is given in this work, but further research must be done.

Conclusion

This research work showed that the snow production in external towers is a possible way to reduce the energy consumption of indoor ski facilities. Further research is needed on a more detailed planning of the refrigeration system for the snow production towers and also on the defrosting method of the evaporators.

Authors: Susanne Lang

Year of publication: 2022

Reference: Skoblickaya, Yulia; Sherement, Anastasia (2019). The architectural and planning organization of the closed complexes for winter sports. Journal of Environmental Management and Tourism 10 (5) 2019.