[SOLVED] Something strange happening with h100i v2

[aedskfnp3]

So i have h100i v2 at front into corsair 460x case with 2 ML fans pushing and 2 stock fans (SP series if i aint wrong), and in a week cycle temperature is changing, no matter of room temperature or anything else, it just starting to get hotter. By randomly checking things inside the case i removed ONE of 2 pulling fans, so i had 2 pushing MLs and 1 pulling SP with same ~RPM. Idle temps dropped from like 36-39 to 30-31, again from day to day rooms temp was pretty different, so even if i tried to connect this 2 factors, i couldnt. So 2-3 days after it became hotter again, i saw 36-39 idle and like +5-10 under games load. U probably wanna know how did i returned normal temps? So i removed second pull fans. And again - 30-31 idle and so on.
I was like - wtf, anything, i mean, anything that i do with radiator, either it adding or removing fans - will improve cooling for 2-3 days? Its happening now for like 3 month. Idk what can it be - maybe something wrong with pump? Maybe i should buy same ML's that are pushing for pull? Please help im tired of removing and adding <mod edit: Watch the language> fans

 

[Darkbreeze]

Regardless of whether the ML fans are pushing or pulling, they are restricting the SP fans. The SP fans have 3.1mmH20 static pressure, which means those fans should be the ones doing the pushing anyhow, plus, the ML fans have not only a lower static pressure with 1.78mm H20 they also have a lower CFM with only 47.3CFM to the SP fan's 62.74.

So if the ML fans are in pull they will increase the static pressure resistance facing the SP fans because they cannot move enough air to even match that of the SP fans, much less be at a higher CFM which is what you'd prefer to see in the pull position, but also, if they were in the push position they'd still be restricting a pull orientation SP fan because it also has a higher CFM and static pressure. No matter how you orient them, it's a bad pairing. Rear fans should have a higher CFM or same CFM as front fans. Front fans should have a higher static pressure than pull fans.

You would probably be better off with ONLY the SP fans in front, pushing, than any orientation that utilizes the ML fans. Maybe use those elsewhere in the build for exhaust?

ML are good fans with a long life, but they don't move a lot of air and have a relatively low static pressure compared to a lot of other performance fans. Personally, if I were really wanting the best performance on that cooler, and didn't much care about what they looked like, I'd put a pair of these on there. No other 120mm fan is as good IMO.

They have about 90% as much static pressure as those SP fans, with about the same overall CFM but about 13db quieter at full speed. That's like going from a vacuum cleaner running in the same room to a box fan running at low speed in the next room.

https://noctua.at/en/products/fan/nf-a12x25-pwm

Either way, I'd get those ML fans out of the airpath of those SPs. Maybe put another set of SPs on there with it if you feel like you need to have push pull, which is ok, so long as the configuration makes sense.

 

[rubix_1011]

Yeah, I'd move the SP fans to push, ML fans to pull, if you're going to do that.

Idle and load temps are directly related to ambient room temp. If it is hot in the room, your temps will always be warmer. Thermal load is almost always calculated as a delta to ambient room temps.

If ambient room temp is 22C (72F) and your idle temps are 30C and load temps are 65C, make note.

If ambient room temp rises to say, 28C (82F), your idle temps will likely jump 6C as well (36C) and your load temps will also mirror this change, likely to 70-71C.

An air or liquid cooler can never cool below ambient room temperature, regardless what that is. If you see low idle temps (30C) when the room is cool, you cannot expect the same when the room is warm. It isn't possible.