what is a passive fan
Discussion
not sure if this is what you are refering to but:
Some motherboards have heatsinks on the north bridge which are cooled by the air exiting the CPU heatsink. If you use liquid cooling on the CPU there is no air exiting the CPU heastsink and thus no air to cool the heastsink on the north bridge. So they include the north bridge heastsink fan incase you want to liquid cool your CPU.
make any sense?
Some motherboards have heatsinks on the north bridge which are cooled by the air exiting the CPU heatsink. If you use liquid cooling on the CPU there is no air exiting the CPU heastsink and thus no air to cool the heastsink on the north bridge. So they include the north bridge heastsink fan incase you want to liquid cool your CPU.
make any sense?
billb said:
just been asked what is a passive fan is in context of a new setup someone has bought apparentely it should be used with water cooling or passive fan or something - whats a passive fan cw normal computer fan?
Thanks,
Thanks,
Never heard of a 'passive fan' I'm affraid. Can you describe what it does? As then we'll be able to tell you what exactly it is, how it works and obviously the most common use for it
Ok. In general terms, PC cooling has the following things.
Fans & Heatsinks. Everyone knows these, you'll find them in 99% of laptops, desktops around the world.
Peltier's, I think that's the right spelling, basically electric cooling. One side gets exceptionally cold the other very hot. You stick the cold side towards the CPU and than either a 'bloody big' HSF assembly on top or more commonly a water cooling assembly (the W/C system in effect keeps the peltier cool as opposed to the CPU).
You also have heat pipes, these are passive devices which, simply put, transfer heat from one area to another. They don't have much cooling ability on their own and usually feed the obligatory 'bloody big HSF assembly', if you have an early AMD shuttle open it and look at the cooler, those things going from the CPU block to the bigger one on the rear are heat pipes.
Passive cooling, to my mind, is just that. It would be a box, with vents, and components simply radiate to the environment in the box and convection is used to keep a small amount of air moving. I couldn't really see a full sized PC being able to do this simply due to the amount of air that needs to be shifted. This is the method that keeps your Sky or NTL box cool.
Having said that, I believe a mini-ITX unit can be brought that uses passive cooling. Although the VIA Eden isn't the most powerful machine on the market.
I would agree that "passive fan" might be one that the system has no control over, although I've never heard it referred to as that before.
Fans & Heatsinks. Everyone knows these, you'll find them in 99% of laptops, desktops around the world.
Peltier's, I think that's the right spelling, basically electric cooling. One side gets exceptionally cold the other very hot. You stick the cold side towards the CPU and than either a 'bloody big' HSF assembly on top or more commonly a water cooling assembly (the W/C system in effect keeps the peltier cool as opposed to the CPU).
You also have heat pipes, these are passive devices which, simply put, transfer heat from one area to another. They don't have much cooling ability on their own and usually feed the obligatory 'bloody big HSF assembly', if you have an early AMD shuttle open it and look at the cooler, those things going from the CPU block to the bigger one on the rear are heat pipes.
Passive cooling, to my mind, is just that. It would be a box, with vents, and components simply radiate to the environment in the box and convection is used to keep a small amount of air moving. I couldn't really see a full sized PC being able to do this simply due to the amount of air that needs to be shifted. This is the method that keeps your Sky or NTL box cool.
Having said that, I believe a mini-ITX unit can be brought that uses passive cooling. Although the VIA Eden isn't the most powerful machine on the market.
I would agree that "passive fan" might be one that the system has no control over, although I've never heard it referred to as that before.
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