Is this a useful amplifier heat sink?

My local recycler just got in a couple dozen of these Thermoelectric-Peltier Cold Plate Cooler & Heater - CP-036

They don't look like they dissipate a huge amount of heat but I am not techy enough to understand the datasheet. What do you think? These ones have the liquid cooling option and the temperature sensor and fan controller boards, I think its intended use was to refrigerate liquid. Maybe a water dispenser or something like that? They want 15 bucks each.
 
Peltier thermoelectric cooling (TEC) elements are solid state heat pumps. They transfer heat to cool things below ambient and usually used to cool sensitive detectors to cool temperatures to reduce noise. Like CCD camera chips. They aren’t meant for transferring a lot of heat flux.

For heat to transfer through the TEC elements, they have to have electrical power. The power generates its own heat in effecting the transfer and that is usually more than the heat being transferred. Generally not considered an efficient effect.

You are much better off using heat pipes and CPU coolers with a slow moving fan. This can transfer hundreds of watts from a MOSFET into the air with very low power applied to spin the fan slowly.
 
Well the datasheet doesn't even say how much heat power it can pump, so not a great starting point - normally you'd expect a graph or a few example performance points.


Peltier devices are not very efficient, but will cool below ambient which a heat pipe cannot do. However the more heat power is pumped, the less the temperature drop it can sustain and the more electrical power is needed to pump the heat. Cooling below ambient isn't needed for cooling power devices, you just need to get rid of the heat. Also you can have issues with condensation whenever you cool below ambient, which is bad news for electronics.
 
I’ve repaired a few similar units over the years in laboratory instrumentation, usually replacing the Peltier elements, which overheat when the air flow is reduced from dust buildup.
For cooling transistors you could remove the Peltier element and just use it as a heatsink. So, you would end up with a heatsink with a thick base and fin spacing optimized for fan cooling. If the price was low enough it might be a viable option.