[SOLVED] Case fans and humidity

[DFace1_2]

We've had an unusually humid week or so in the UK and I wondered if anybody could shed some light on this.

I just upgraded from a Bequiet pure rock slim to a Noctua DH-15S for my 3600 oc'd to 4.2 all core at 1.15v. I know it's overkill but I wanted to see what it can do. Cpu temp has gone down 10-12°c whilst gaming.

Is it better to have the case fans running higher or lower when the ambient air is unusually hot and humid? I'm sure when I notched all 4 fans down a bit, the temps got a little lower because there was less humid air being pulled through the system.

 

[mamasan2000]

Just thinking about it from the overclocking side, the summermonths usually brings out people with systems that are unstable and/or overheating. Ambient temp is higher so you need faster fans to cool stuff down. And some radiator fans top out at 1600 RPM. Those fans are useless to me. I need at least 2300 RPM, to have some wiggleroom. Say ambient temp rises by 10 C and CPU temp by 15-20 C, how are you going to cool that? Can't run the same fanspeed, you will overheat.
Another way I like to think of it is, a floorfan. Say you bought a big floorfan and it's 30 C in your room and you pointed that fan at you. Will that fan cool you down or heat you up? It's gonna be colder air, right? And the faster the fan spins, it's going to be even colder.

What I wonder about is, cold air weighs more right? So how hard is it for a fan to push cold air vs hot air? Is it such a miniscule weightdifference it doesn't matter? Hot air should be easier to move. Is the difference so small, you can equalize it and remove it from calculations?
Hot and cold air matters for altimeters, does it matter for fans?

 

[DFace1_2]

Just thinking about it from the overclocking side, the summermonths usually brings out people with systems that are unstable and/or overheating. Ambient temp is higher so you need faster fans to cool stuff down. And some radiator fans top out at 1600 RPM. Those fans are useless to me. I need at least 2300 RPM, to have some wiggleroom. Say ambient temp rises by 10 C and CPU temp by 15-20 C, how are you going to cool that? Can't run the same fanspeed, you will overheat.
Another way I like to think of it is, a floorfan. Say you bought a big floorfan and it's 30 C in your room and you pointed that fan at you. Will that fan cool you down or heat you up? It's gonna be colder air, right? And the faster the fan spins, it's going to be even colder.

What I wonder about is, cold air weighs more right? So how hard is it for a fan to push cold air vs hot air? Is it such a miniscule weightdifference it doesn't matter? Hot air should be easier to move. Is the difference so small, you can equalize it and remove it from calculations?
Hot and cold air matters for altimeters, does it matter for fans?

Well now I've got even more questions! 😂

 

[hotaru.hino]

Is it better to have the case fans running higher or lower when the ambient air is unusually hot and humid? I'm sure when I notched all 4 fans down a bit, the temps got a little lower because there was less humid air being pulled through the system.

It's likely because humid air can hold more heat due to the water saturation, and water is a rather excellent battery, if you will, of heat.