XtremeComputing posted a review on the AMD K8 Kooler (tec)

In a normal application of a TEC, they are not implemented inside a heatsink unit but as a heat transfer between the heatsink and the CPU. It is necessary in that situation to have the TEC transferring all the heat from the CPU to the heatsink.  That means you need a TEC which is capable of transferring more heat than the CPU can put out.   The danger is that if the TEC doesn’t do it’s job for whatever reason, then the CPU will just get hotter and hotter.  If the TEC switched off or burnt out, there would be pretty much no cooling on the CPU, which is bad...  also the heat output on the hot side is usually a lot more than just that on the CPU side, so you get a cold CPU, but a very hot heatsink – which is why they are not used very much outside of water cooling

MACS Airconditioning - AMD K8 Kooler (tec)