how does humidity affect cooling?
 

after i put my new block in, i got 17deg air-cpu diff. it was very consistent up until 3 days ago. that is when i started leaving my window open for the night because i sleep at my GF's house anyway. i thought, why not let mother nature do its work since it's getting really cold here. now my diff is 20C (!!!), has been like that for a few days. i noticed that my room's humidity went from 60 to 80. room temp is 16C, CPUburn gives me 36C; with the 60% hum i was having room temp of 26C and CPU of 43C. can higher humidity decrease radiator's efficency? it could be other things, like something stuck in the WB, dust in the rad fins, something stuck in the pump, but i wanna know if hum can actually have a negative effect before i start taking it all apart.

ok, false alarm:) i broke the piggy bank and got another Cnurse. air temp just before the rad is 22C and CPUburn (after an hour or so) is 39C. so the 17deg diff is back. my guess would be that the room thermometer i was using got affected by the sudden changes in air temp. we had freezing temps last night! phew:D hey, at least now i can know my water temp as well...

Humidity will only affect cooling with an evaporative cooling tower.

such as mine

This is why I have it exhaust out the window :)

that's what i thought, but wanted to make sure im not missing anything:) but whatever, i have 2 gauges now, so i'll know what's going on, without having to rely on that stupid thermometer.

side tracking abit here...

how does humidity affect tec-ing?
a rig in singapore compared to a rig in some wintery country, the amount of condensation formed...is it a very significant extra amount? a european prommie reseller mentioned that prospective singaporean buyers should get the heating element, would more grease do the job just as well?

well the dew point will vary based on humidity I believe ... either way, when you've got something that far below ambient temperatures you're going to have condensation buildup unless you A) keep humidity at 0%, which would be a hard task, or B) seal it off with a heat insulating substance, like neoprene.

Technically, the humidity can cause insignificant variations. It isn't extreme, but it could be noticeable. The more humidity, the more water in the air. The more water in the air, the thinner the air is (water particles are more spread out than oxygen/nitrogen/all other gases). So on a very humid day your rig might not cool as well, because it's actually forcing less air through the rad. On a very low humidity day, it might cool better.

But we're probably talking MAYBE .5* C from extreme humidity, to extreme dry.

You also have to factor in that on a Humid day, because your fans are forcing less air, they are probably spinning faster. On a less humid day, they are probably spinning slower, because of the thicker air. So it's probably still pushing the same amount of cooling power through the Rad.

...and here I was thinking the reverse!

More humid air would have a higher heat capacity, and since the water is in microform, it should be able to allow for a quick transfer of heat. All it's going to do though, is be a little more efficient at reaching the ambient temperature.

You have to keep in mind that a PC would typically be in a house, where the humidity would range between 20 and 50%.

Well, is there any tests made that confirms either of the statments abowe? Or is some of them a well known fact?
Since I am on the brink to do some testings on my water rig is it maybe an idéa to bring the setup to the "climate controlled lab" at work? Any thoughts?