It's quite a system. It's an industrial chiller which circulates sub freezing temp glycol (sub freezing for water, not for glycol) through a series of 1/2" tubes which are spaced close together. Sometimes the tubes are on concrete; sometimes sand. In this case, concrete. Water is sprayed over the tubes in thin layers so it freezes quickly. Once the ice is above the level of the tubes, it's either painted white and then with the lines, logos, etc; or a white tarp with the lines, logos, etc is spread out. This is the newer way of doing it. In the old days, they were all painted. Then more thin layers of water are sprayed on to build the ice up an inch or so above the level of the tubes. All together, the ice is somewhere around an inch and three quarters thick. The ice is kept somewhere around 26°F, I forget what the optimum temp is for hockey, but it's around there (26°). Apparently, figure skaters like the ice a bit colder than hockey players. If it's too cold, it gets brittle and then big chips are carved out when a skater turns hard.
The building HVAC system is separate from the chiller system.
It can be a challenge to maintain ice quality during summer, that's for sure, especially in a smaller building where the outside walls are close to the ice surface.