Vaughn Simon writes:

I have often wondered if a flow-through tank in the shop 'fridge would
work. I guess it would depend on the flow rate.

You need a phase-changing substance in contact with the heat exchanger,
like the boiling Freon in a commercial unit, or melting ice in a improvised
design.

So no, cool air in a refrigerator doesn't work effectively, because it
can't transfer much heat.