on ice rinks

They pour water in a very shallow ''tank they put coils containing antifreeze in the water and connect to a very large ''refrigerator'' that pumps supercooled antifreeze solution in there. They do not use water in the pipes because it would freeze also.
For ''portable'' rinks (e.g., Ice Capades) they have huge trucks outside that have enormous refrigerators on them. After the last show, they break the ice up (usually) and let it melt.

One word: Zamboni

You are too cute!

There are water pipes that fill up the rink. Then there are coils that freeze the ice right where it stands.