I tend to agree. You can see what appears to be the inlet and outlet ports for glycol lines on the top edge. I think I understand what the OP meant by a square coil. The tubing itself would not have a square cross section, but the overall shape of the coil would be square (or more accurately, rectangular). What scares me a little are what look like wire nuts making electrical connections in the water/ice chamber. Maybe that's not what I'm seeing or it's only low voltage current, but it's something to check out for sure. Whomever sold it should be able to provide some information on what it was or is.It actually looks like a glycol chiller/reservoir to me, but I don't know for sure.