Possible condensation?

[Kenjutsu]

If you take an external WC reservoir, and fit it into a USB Fridge, could condensation occur inside the PC?

[Nuke]

I don't know about condensation, but that fridge is not going to help much to cool a CPU. You will need something that can extract atleast 75W(depending on the CPU you have)

[Prime]

Sorry, i know this is off topic but given that the max current from USB is 500mA, how on earth will it power any sort of fridge?

[WiK1d]

It uses a small peltier.

http://www.everythingusb.com/mini_usb_fridge_12625.html

[Kenjutsu]

After reading the review, it does not seem as if it will make that big a difference on the water temp in the res, seeing that the water is constantly being circulated through the loop by the pump. Maybe if it is left running for a couple of hours, there might be a noticeable drop in temp?

[Synthesis]

To answer your condensation question:

Any time you put an object that's cooler than the ambient air temperature in air that's not at zero per cent relative humidity, water can condense on it. Whether water actually will or not's determined by the temperature of the object and the humidity - the higher the relative humidity, the closer to ambient temperature an object can be and still attract condensation.

The cold side of a working Peltier is considerably cooler than ambient - that's the whole idea - and so it'll get damp. Over time, with a few high humidity days, it'll get damp enough often enough that the area around the cooler will suffer water-assisted corrosion.

You need to do some non-trivial sealant work to keep condensation away from contacts.

Condensation is, by definition, distilled water; it's not conductive or corrosive in and of itself, so it won't foul things up nearly as much as, say, splashing an equal amount of cola on your CPU. But all sorts of things will very slightly dissolve in condensation, making it conductive and encouraging corrosion. And water can also transfer soluble gunk on a board to places you don't want it to be, and cause havoc when it bridges contacts and changes the capacitance between them.

A motherboard is very likely to survive being splashed with clean water, but it's not likely to keep working properly while it's wet.

Ideally, an active-cooled CPU should be not just thoroughly surrounded with waterproofing material, but that material should also insulate it from the surrounding air well enough that condensation on the outside of the waterproofing is negligible. This is generally not a hugely complex engineering task - but doing it in a way that lets you easily remove the CPU later is trickier.

As for your solution:


Just get yourself a peltier element and stick it between your CPU and heatsink. USB Fridge.....WTF?

Nice Guide and explanation

[Prime]

Thanks Wik

assuming 5V and assuming a max current of 500mA gives you a power consumption of 2.5W.
Thats Peanuts. and further taking the carnot efficiency which is the maximum efficiency of the device, which iirc is [T(hot)-T(cold)]/T(hot) and cooling from 300K down to 290K gives 3 percent efficiency. 2.5W*0.03 = 0.075W. Thats about the max amount of heat transfer you'll get, and in fact, it will be well below this.

So dude, Don't waste your money.

If i knew more, i'd do a calc of the rate of energy loss of the can. hmmm let me think on that one.

[WiK1d]

Yeah, that USB 'fridge' is definately a waste of time and money. And it will surely not cool a water loop down at all.