A builder in the above post finished his unit like this:
Original thread:
First Chiller - EXTREME Overclocking Forums
With this type of unit, you don't have to worry about reversing the cycle. The units are made to only provide either heating or cooling on the air side. If you want both, you build 2 units. Due to the low cost of abundantly available used window a/c units and rubbermaid coolers, they are very economical. The most difficult part of building one is fitting the heat exchanger and copper tubing inside the water vessel without creating a leak (refrigerant or water).
The main difference in the mechanical design is the water flow. The "computer coolers" use a constant volume of water and a small mag-drive pump to recirculate their water. In a pump and dump rig, you would use a valve to control incoming ground water and an overflow tube like a toilet tank. With a cooling unit, you must also devise a way to drain the weeping evaporator.