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by zevv 330 days ago
Could you summarize the contents of this video so we don't have to watch it?
4 comments

I haven't watched it recently, but here are the main takeaways I remember:

Peltier coolers are neat because they're very small and quiet - as opposed to vapor compression systems solutions. However, they are an order of magnitude less energy efficient.

Also Peltier coolers still have to obey the laws of thermodynamics, which means that to cool one side of the mechanism, you must heat the other side. In order to do any substantial cooling, you need a way to dispose of that heat on the other side. This usually involves the use of radiators and fans, which negate much of the size and noise benefits.

As a result, Peltier coolers are pretty niché. Your use case would have to require only a little bit of cooling. You'd have to need a form factor that cannot accomidate a vapor cooling solution. And you'd have to be willing to make the system very energy inefficient.

AFAIK, no one has tried to build a Peltier cell paired with a heat pump. I am not an expert, but I would imagine that it's a path that could bring higher efficiencies. Thoughts?
It seems to me that if you have a heat pump, you don't need the Peltier anymore.
The heat pump is already so efficient that, I assume, adding something less efficient just makes it worse.
Also not an expert, but I’m struggling to find a combination where one of those couldn’t be replaced with a passive thermoconductive element. It’s hard to beat the efficiency of “free”.
It would be more efficient to just make the heat pump slightly more capable of cooling to reach the same total performance
It's one of those cases where you can chase a very small relative gain by adding a lot of complexity.
Like horsepower.
Heat pumps have a COP of 3-4, add in an evaporative cooling tower for a COP of 7. Peltier coolers will always have a COP of less than 1 (.1-.5?)

Unless you want to spend more energy that you remove in heat, stick with heat pumps and cooling towers.

Thank you; finally some data about actual potential.

COP = Coefficient Of Performance, BTW. (Heat out) / (power in).

> Could you summarize the contents of this video so we don't have to watch it?

Thermoelectric cooling is not very good and takes a lot of energy to do.

They are very inefficient
I think there are some applications though. I remember PWMing a peltier element to cool something to more or less exactly 35°C. I didn't need to be efficient cooling, it just needed to be reliable under space constraints.

I am no hardware guy and I remember there was a giant heatsink despite the constraints. It was some kind of photosensor + lamp if I remember correctly.

I think there was also some software logic to reduce water condensing at something too cool compared to the ambient temperature.

Obviously there are applications. There's one on my CPU.

The question is: Are there large-scale applications?