A simple but clever water chiller idea from the computer overclocking community

[mandarinman]

but a fail safe needs to be build in in case of it blocking up. But yes I would also use the free gravity to drive the water flow through this system.

it would only block up if you had bioballs in the upright. but i think it would make a noise and reduce air speed up and out of tube and also reduce the ability of the air to carry heat. because the bio balls would retain heat and return it to the water running over them