Franco sent in this article detailing his new method for affordable cooling –
The construction was fairly simple. It only took me a few hours. I used a 20 litre plastic container to house the heat exchanger and also hold the cooling medium which is ice-water in this case. I made the heat exchanger roughly 7 mm (0.7 cm) wide and 20 cm high to promote a high rate of cooling, and also to compensate for a shorter flow length than was used in the previous version. To prevent leakage the gaps were sealed with silicone (which happens to be DAP 100% silicone for this particular project – great stuff and it cures fast!).