Feasible if you found one at a junk yard, but copper tubing is $20-30 and some fittings makes a tubing idea sub-$100 probably. An AC is about $300, a new radiator without fittings starts at $70 and are built for cars not box fans so it might be more challenging to get to work.
With that being said, environmental, energy, and other contextual concerns might out weigh the cost. A mini-split heat pump is probably the most sane thing to actually install, but that’s a big ask.