I’ve searched around and mostly seen people create custom radiator builds attached to their water supply, but that’s beyond my skill level and I’m not sure if linking it directly to the water supply via piping would violate the lease or not. Are there any solutions a bit more DIY that I could take advantage of?
Gut an AC from the dump. Replace the condenser with a tube in tube heat exchanger, using your cold water as a heat sink. Brazed plate HX if you’re feeling rich. Replace the cap tube with a TXV for better load tracking. Recharge with R290.
T Sure this is even further beyond your skill level but is the best possible way to use a source of cold to chill your apartment. You can locate it anywhere convenient, not just by the window. You could likely get a COP over 5 and be discharging the water in a fairly modest stream at around 30-40C.