Its true, check out 4Ryan6's thread for a method of how you can attempt sub ambient cooling, sub-zero is harder still to balance but very possible http://www.tomshardware.co.uk/forum/275185-11-exploring...
but beware, this is a very expensive and time-consuming venture, are you sure you want to take the red pill?
The D.s. system uses a peltier, or thermo-electric plates, to heat up one side of a plate which cools the other side, the hotter the hotside gets, the colder the cool side gets,
you have to manage the heat created by the hotside to allow the cold side to do its thing, and in this case it looks like they are using the four rads to do so,
If you set up a regular loop like that you would get a low delta, but not sub-zero, its the Tec that is making the difference there
4ryan6's thread about sub-ambient would be where you'd want to go for TEC- that's what he is using for his sub-ambient temps, but you could go as simple as adding ice to a large reservoir to drop temps.