i have pondered this theory before.
with ac the change in refrigerant state causes a high and low pressure range. when a car needs gas topped up its because the high pressure is not reaching the required pressure so when the state is changed it is cold.
if this would be possible with water would certainly interesting.
to throw another theory into the mix. an my appologies if how i think they work is incorrect.
The breathing air supply for sand blasting has a CCT, climet control tube, this tube has a single air supply, then inside the tube it splits the air, one sends air to the helmet, the other sends air out of a waste valve. by increasing the air flow out of the waste valve it will reduce the temp of the helmet 20degC. and vise versa.
Havent never pulled one apart i presume they work via the waste air passing the breathing air in a heat exchanger. one does multiple passes compared to the other single pass.
If anyone could find out the science behind these, they could add some possibilities into using water for a below atmos temp cooling system.
another note - air being able to absorb the most energy, aka heat, but needs physical control for this to occur. by simply increasing the air flow could this force the water temp lower than atmosphere.