How Does Humidity Affect a CPU temp

[Endeavor]

because this just accured to me,
san diego (being right next to the ocean) is always humid (70%+ year round) does this mean that the tiny water particles help cool the HSF which allows it to run cooler? because ive never had any heat issues with my CPUs

[Octoman]

I believe that the higer humidity does allow it to cool the hsf, because the water vapor invreases the heat capacity of the air, therefore allowing it to cool more. However, humid air is more dense and flow less, so you may not be getting the rated cfm from your fan. A detailed analysis would need to be done to see how the two offset eachother.

[deez]

I'm in Louisiana where we also stay extremely humid all year long....but it also stays extremely hot here all year long. If anything i think humidity increases temp and decreases life of components. Moisture is bad for electronic components of any kind.

[Endeavor]

yes i know, but its not hot here in san diego, so its cool and humid so i was thinking maybe that could help me with cooling

and all eletronics are waterproof TO SOME DEGREE (proof is that there is always or almost always tiny water particles in the atomosphere)

[deez]

Essentially theres not much you can do about humidity...it may help with cooling in the right weather conditions

also may increase temps b/c low boiling point of water may bring moisture to the temp of the surface it makes contact with

just a theory...would make an interesting study though...if you could do it without frying any components :-)

[Endeavor]

i dont think humidity affects boiling temps
and processor doesnt get hot enough to produce boiling temps

[AmbientFiction]

Their is something to do about thier is a fluid that 3m makes its about $500 a drum non conductive liquid you can dunk your board in it and turn that sucker on without problems

[Endeavor]

AmbientFiction (Jul 30, 2001 11:49 p.m.):
Their is something to do about thier is a fluid that 3m makes its about $500 a drum non conductive liquid you can dunk your board in it and turn that sucker on without problems

whachutalkinbout willis?

[Shadow ÒÓ]

Moved post to cooling.

[cjtune]

Just checked from my psychrometric chart (@ 1atm): Density of air at 25'C, 10% relative humidity is 0.847m3/kg while at 25'C, 70% humidity it's 0.864m3/kg (1.18kg/m3 vs. 1.16kg/m3). Since the power to move fluid for fans at a constant speed is directly proportional to fluid density, (P=Cp*(density)*D5*n3), there won't be much difference in effort in the part of the fan to move more humid air. In terms of sensible energy, the enthalpy difference of 10% humidity air from 25'C to 30'C is 8 kJ/kg while for 70% humidity air it is 17 kJ/kg for the same +5'C increase. That's a whopping 113% increase in specific heat capacity!

[M@€$†®Ö™]

wow interesting info I never knew thanks :)

Maestro

[cjtune]

Eh, BUT usually the most humid air is also the warmest air (warm air has bigger capacity for moisture), like in the tropics where I live. The really cool humid air would be from a building HVAC that both cools the air and humidifies it for the occupants' comfort. Unless you live in a well-maintained apartment or spend lots of time in a office block, then you won't be getting such 'good quality' air.

[CalCoolage]

cjtune (Jul 31, 2001 02:03 a.m.):
That's a whopping 113% increase in specific heat capacity!

You've got the numbers. I was just going to mention that this is something you hear about in climate and weather. Temperature changes are more drastic in dry than wet climates, evidently because water vapor stores so much heat. Weathermen sometimes mention that high humidtiy keeps night temperatures from dropping much, so on the muggiest days you get the least temp drop at night.

It is the high heat capacity of water that makes it more effective for cooling than air, is it not?

In effect water stays at lower temp for a given uptake of heat, and so keeps the temp difference larger, impoving heat tranfer.

[Endeavor]

so more humidity means cooler CPUs?

[maha_x]

hmm, most interesting... If one could bring highly humid air or even steam to the heatsink, it could then take energy while vaporizing.

Enter mad cooling ideas:

Closed aircooled system. Has small water reservoir with heater to vaporize (humidify?) the air, radiator to cool the humid air, and some sort of ducting to take the air through the HSF. Certainly not better than water cooling, but more safer if leaking...

[Quaky]

I think if you heat up water to make it evaporate, the heat is still in the water when it hits the cpu. You could try it if you can make water evaporate without heating it up first. That way you may achieve some temp difference. Also make sure you don fry your parts with condensed water dripping of the heatsink. If anyone is actualy mad enough to try it, I would really like to read about it here. :D

I don't know this for sure though, but it seems logical to me, and it is kinda backupped by my fysics lessons from the past years. :)

[CalCoolage]

Endeavor (Jul 31, 2001 10:22 p.m.):
so more humidity means cooler CPUs?

Absolutely, positively. IMO!

[Gus]

Endeavor (Jul 30, 2001 11:53 p.m.):
AmbientFiction (Jul 30, 2001 11:49 p.m.):
Their is something to do about thier is a fluid that 3m makes its about $500 a drum non conductive liquid you can dunk your board in it and turn that sucker on without problems

whachutalkinbout willis?

I think AmbientFiction is talking about Fluorinert. He's right! Its non-conductive and you can submerge the whole dang motherboard in their with no problems. Check out the link!

http://www.octools.com/articles/submersion/submersion.html

I wouldn't call him crazy! But the guy on that site is really out there. Couldn't believe it till I seen it!

[Gus]

Alright! Whats the deal on the HTML tags?

[cjtune]

Remember fellas, it's cool, humid air you want. It's also next to impossible to get totally dehumidified air unless you live in the poles or with the aid of some dehumifying equipment. Evaporated water will only release latent heat when it condenses onto some surface but usually this is achievable only when you forcibly cool the air until it hits a satured humidity level (100% relative humidity, cold air holds, relatively, less water vapour but the amount of water vapour held is still the same), in effect taking away the latent heat.

[vimal]

maha_x (Aug 01, 2001 01:50 a.m.):
Enter mad cooling ideas:

Closed aircooled system. Has small water reservoir with heater to vaporize (humidify?) the air, radiator to cool the humid air, and some sort of ducting to take the air through the HSF. Certainly not better than water cooling, but more safer if leaking...

If you make it a really nice and tight closed air cooling system, substitute ammonia for water. This is the basic technology used in icemakers waaaaaaaaaaaay back in the day (when overclocking consisted of greasing your slide rule)

What they would do is have large tubes, spray ammonia into the bottom, pump out and compress the air at the top, and circulate it to be sprayed again. Ice shavings appear on the sides of the tube, which were then scraped and compressed.

[BobbyDigital]

Hi
Humidity in SanDiego? haha I laugh at you. I just got back from this huge ass lake called "Lake of the Ozarks" its in the middle of missouri in the forest swamp lands. I live in cali for half my life and thats nothing. I live in colorado now and its totally dry here. if theres hella humidity in San diego why does california have a drought almost every year? Hehe
Humidity is not good for your cpu. Because humidity always raises the air temp kind of like wind chill is at winter its not actually -6 but it just feels like that. In Florida I once went into one of my dads partner company buildings when we were there for vacation. I found there server room and a network guy was in there and it was dry ass cold air in there for all that equipment. He said they have industrial size humidifiers just for that room including two massive ac's

[JigPu]

I like the closed system idea. You could also go and take a humidifier (my mom has one) and duct the output to your heatsink. The humid air would take away more heat, so you would have more effective cooling. Also, you could somehow duct the air coming out of the heatsink to outside your case if you are concerned about condensation. I think that would be a great idea.

JigPu

[fresh2000]

if your looking to dehumidify the air why don't you just get a bunch of those crystal packs that come in you shoe box (or other places)? The crystals suck up air humidity.

[ZX-Tex]

Humidity has a big effect on evaporative cooling. But for regular forced air convective cooling it really does not make much difference. I have taken humidity into consideration during heat exchanger testing at work, and it is basically below the measurement error of most A/D convertors (thrmocouple readers) and can be ignored.

So, the short answer is, no. :-)


Endeavor (Jul 30, 2001 02:53 p.m.):
because this just accured to me,
san diego (being right next to the ocean) is always humid (70%+ year round) does this mean that the tiny water particles help cool the HSF which allows it to run cooler? because ive never had any heat issues with my CPUs

[CalCoolage]

ZX-Tex (Aug 01, 2001 09:07 p.m.):
I have taken humidity into consideration during heat exchanger testing at work, and it is basically below the measurement error of most A/D convertors (thermocouple readers) and can be ignored.


So doubling the heat capacity has no effect on the cooling ability of a fluid. Does heat capacity enter into the calculations at all? What property of water makes it better than air for cooling?