pc po³-640 Negative airpressure? Is there a way to customize the auto mode?

So I have thi pc po³-640. I keep monitoring how the fans work through predatorsense. Now, the thing is on auto setting the air out fan at the back is spinning faster then the intake fan @the front, resulting a slightly negative air ressure inside the case.I have the glass on so the air cant really come in elsewhere, just on the top of the case. The thing is I belive it would be better to achive a positive air pressure, so the front fan has to work less and the warm air is going out instead the coller come in.

The problem is that in the custom setting the lowest fan speed is 60% that makes tha fans work too hard. Literally spinning time and a half faster on default then on auto mode.

Is there a way to customise the auto mode? Is there a way the put another intake fan somewhere? The only way I can think is on the top, but there are no holes for extra fans, and i would need a header splitter but is it a good idea? Anybody modded the case before?

[Edited the thread to add model name to the title and issue detail]

Accepted answers

billsey

My thought is that Acer's designers are working under the assumption your ambient temperature in the room is such that a slight negative pressure is better for cooling. The downside to that is that you will eventually catch more dust in the system, unless you are in a particularly clean environment. Remember that a fan running at 60% speed doesn't mean it moves 60% of the air in relation to a fan running at 100% speed. For typical computer fans the curves look kind of like this:

All comments

chugzilla

well i have the PO5-640-UB11 and in predator sense when my 4 fans are in auto the 2 front the single rear and the CPU all are about the same at 650 only the gfx card is higher in auto it's at 1100. I'm not sure if you could add another fan i have never seen the inside of your case but ill look into it and rule of thumb is anything on the top is exhaust and intake is the side...front or bottom. what's nice about the 5000 is they have a bracket at the top so we can add 2 fans up there but that's it without modding it ourselves but i have seen pics where someone put a fan between the PSU and GFX they just failed to mention if it was exhaust or intake. and why lol so with that being said i just put in a new noctua cooler and put my extra fan up top works great. and when i game i always run in gaming mode to get the best performance out of the pc if u want quiet fans, you need noctua ones the acer ones are not quiet lol. so, what are the readings you are getting on the front and back? and what's your full model PO3-640-????

well i just went through the owner's manual and looks like you could add one in the front they have the indentation there but no cutout so that would be a lot of careful work and then it looks like you have a really nice, ventilated side panel? ide attach 2 more fans there and use y cable splitters to attach them to the existing front fan and rear fan header on the MB but have both as intake.

billsey

My thought is that Acer's designers are working under the assumption your ambient temperature in the room is such that a slight negative pressure is better for cooling. The downside to that is that you will eventually catch more dust in the system, unless you are in a particularly clean environment. Remember that a fan running at 60% speed doesn't mean it moves 60% of the air in relation to a fan running at 100% speed. For typical computer fans the curves look kind of like this:

Kz00

Right, there is not too much difference between the rpm of the fans, but the exhaust is always faster like 10% or so. Heat is not a problem, but dust is. This is why I like to make positive pressure inside. I will check the case, i have seen the place where i could put an extra fan, but yeahh...i need to cut. Or i swap the front fan with another one that can create more pressure. Or side panel...yes, but the glass is so nice

Kz00

Yes,I have checked it and it is 100% that the default fan settings create a neutral/slightly negative pressure inside the case. The position of the intake fan is not the best either. The easiest solution is to rise the RPM on the front. Now the problem is that in nitrosense the lowes custom setting 60%of the max speed it the fan what is twice as fast than de default setting. Default is around 1000rpm. 2000 is a bit noisy and unnecessary fast when the pc is in idle. I think 200-400 more on the front and 100less on the back would be ok. I just need to find a program that can control tha fans better.