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* They replace all 'cooling fans'. Anything hot can be cooled while reclaiming energy. Nope, to reclaim energy you need a temperature difference. If you want

* They replace all 'cooling fans'. Anything hot can be cooled while reclaiming energy. Nope, to reclaim energy you need a temperature difference. If you want that difference, best bet is to use a radiator with a cooling fan. Inserting a device between your heat source and your heat sink will decrease transfer of heat.

bobthebuilders 5y ago
Doesn't something hot (in the way we colloquially use the word) have a temperature higher than the surrounding air/metal/whatever?
usrusr 5y ago
When you have a gradient and you want that gradient removed you can allow the gradient to do some work while it excuses itself. When you have time/throughput constraints that you can only achieve with a fan then yes, adding something extra in between will likely fail making up for the additional fan power required. But in the same way as you could do away with the fan by increasing the size of the radiator involved, you could also tolerate a gradient harvester in between, by making the radiator even bigger. No physical principle broken. Economic principles broken? That's another story...
flavius29663 5y ago
> will decrease transfer of heat for the same size of cooling fan + device. You can always increase the fan if it means you're also going to recover some energy. I don't see why this wouldn't work tbh. Say your CPU is hot and the room is cold. The desire end state is that the CPU will reach room temperature, with the room being warmed up a little (let's not talk about getting the energy out of the room). There is no alternative to this end state. To reach the end state, you can dissipate the heat of the CPU in the room "as simply as possible", OR you could transform some of it to electricity, and use the electricity to power some other device, say a desk lamp, and heat the room that way.
- yetihehe 5y ago
  Yes. This currently a little impractical because all cpu are on edge of their thermal transfer capabilities, so adding such device would cause termal throttling. It's very possible, just not economical yet.
blacksmith_tb 5y ago
I took that to mean something more like "in cases where we already exhaust waste heat, you could reclaim some of that energy". That does seem doable, my refrigerator is a little heat pump in reverse, why not stick a Peltier on the coils on the back and charge a battery to run LEDs to light the inside?

bobthebuilders 5y ago

Doesn't something hot (in the way we colloquially use the word) have a temperature higher than the surrounding air/metal/whatever?

usrusr 5y ago

When you have a gradient and you want that gradient removed you can allow the gradient to do some work while it excuses itself. When you have time/throughput constraints that you can only achieve with a fan then yes, adding something extra in between will likely fail making up for the additional fan power required. But in the same way as you could do away with the fan by increasing the size of the radiator involved, you could also tolerate a gradient harvester in between, by making the radiator even bigger. No physical principle broken. Economic principles broken? That's another story...

flavius29663 5y ago

> will decrease transfer of heat for the same size of cooling fan + device. You can always increase the fan if it means you're also going to recover some energy. I don't see why this wouldn't work tbh. Say your CPU is hot and the room is cold. The desire end state is that the CPU will reach room temperature, with the room being warmed up a little (let's not talk about getting the energy out of the room). There is no alternative to this end state. To reach the end state, you can dissipate the heat of the CPU in the room "as simply as possible", OR you could transform some of it to electricity, and use the electricity to power some other device, say a desk lamp, and heat the room that way.

yetihehe 5y ago
Yes. This currently a little impractical because all cpu are on edge of their thermal transfer capabilities, so adding such device would cause termal throttling. It's very possible, just not economical yet.

blacksmith_tb 5y ago

I took that to mean something more like "in cases where we already exhaust waste heat, you could reclaim some of that energy". That does seem doable, my refrigerator is a little heat pump in reverse, why not stick a Peltier on the coils on the back and charge a battery to run LEDs to light the inside?