Opinion poll: Case pressure preference, and CPU fan direction

Hello friends!
It's summer time in this part of the world, and the need for good cooling has demanded acknowledgement again (Anyone who has lived in Texas knows what I'm talking about) :dead:
To satisfy those needs on air cooling, I've come up with a mod which I will be posting in some time.
Now comes the problem: The guide will be on a "works for me" basis. So how can I make it applicable for most people? To solve that problem (somewhat), I've got the option of a poll.

Here are the things which need to be considered:
1) Case pressure: Case pressure is the pressure co-efficient of your case's airflow. E.g. More intakes and less outlets create a positive pressure co-efficient, while less intakes and more outlets create negative case pressure. Note that this does not mean "all intakes, no outlets" or "all outlets, no intakes". It means intakes and outlets both working at different magnitudes.
Though this may appear irrelevant to some, this has a lot of effect on the rate at which heat is vacated from the case.

2)CPU Fan direction: This is a topic in which there is much disagreement. Some believe a fan blowing away from a CPU is better, some believe a fan blowing onto it is better. However, most modern systems have fans blowing onto the CPU. As this changes the airflow pattern in a case, it can fundamentally alter the scheme of my mod.

As always, I'm open to suggestions for improvement. Any poll options will be added as necessary.

Cheers! :grinthumb

Im getting " You may not vote on this poll"..

Positive case pressure to keep dust out and cpu fan pointing out the back of case, though if i did not have a choice it would blow at the cpu, to cool the chipset too.

Same here.

I have a 1 intake, 2 outtake setup, with the CPU fan blowing on to the processor. Never thought to change it, worked fine for years temperature wise.

I'm getting the same "may not vote" thing. But maybe that's because I started this thread. Anyway I'll contact Leeky and let him know about the issue.

I have exactly the same configuration as yours, with the only noticable dust being on the HDD. Do you experience a similar problem?

Yeah, spot on. The HDD that i have directly behind the intake (with the intake being at the front) gets a nice pile of dust every few month.

It's no trouble though, comes off rather easy with one wipe.

Exactly
TBH, even that dust can be slowed down by using filters at the intakes. I'm planning on using thinly sliced Scotch Brite Scouring Pads as filters for the mod. That should do the trick. Let's see how it works.

Not a bad idea. I have a set of double front grills myself, they give me a few extra weeks before cleaning is required.

First entry checked with no problem.

I will take that into consideration.
The key is that hot air should be transferred out quickly, it should not recirculate, and cool air is sucked in with the least possible impedance by filters. The only thing I have to worry about now is the HDD and RAM cooling. It isn't falling in my airflow pattern well. This project is getting far more massive than I had anticipated.
It is captaincranky's opinion that I'm waiting for now. As much as I hate to admit it, he always has something valuable to say. Let's see what others have to say till then.

Im curious as why so many people have chosen negative air pressure?

I was led to believe that this encourages dust to be sucked in to all the little gaps in your case, And can cause a vacuum effect with shrouded gpus in the worst case scenario?

Negative air pressure does attract more dust, but it draws more outside (cold) air through the system. It gets the air in to equalize/diffuse with the ambient temp, and gets it out of the case faster. whereas positive pressure has the incoming air hanging around a bit longer to absorb more heat and keep the case ambient a bit higher. It traditionally has been a few degrees cooler than a positive pressure setup. But then you have a lot of different configuration and placement issues to consider....but that is why most 'enthusiast's opt for it. However you are talking about a system that only has the compulsory front intake fan and rear exhaust, you are generally not talking a huge difference. Many more people have a problem with fan layouts with airflow that work against each other (see the 'all important side-fan') before they even get to the pos/neg issue.

When you have positive pressure, i.e., have more fans blowing in air, you are also blowing in dust. I wonder how people can overlook that simple logic.
Positive case pressure brings in cool air, and tends to keep it trapped in, creating hot air pockets. Neg pressure, on the other hand, removes hot air out.
Cooling depends on not how fast cool air is moved in, but how fast hot air is moved out.
Looks like I'll have to explain this in more detail in the guide to clear any misconceptions.

Red1776 said:

Marnomancer said:

1) We said the same thing...

2)Nobody is disputing that there is dust in the air, neg or positive. Negative pressure just introduces more air through the system, thus is a bit dustier.

Marnomancer said:

3)Any chance you might do that without your superior condescending BS attitude?

No offence, but I'm trying to be superior. My apologies if I offended anyone. I was merely stating that it is overlooked by most. Some people state that it 'keeps dust out'. Which I found preposterous. If filters are used at every possible opening, the accelerated dust accumulation can be slowed down. I'm saying that from experience.
Apologies again, though I'm still confused over what I'm being offensive.

You really don't know why that would be offensive?
Because for those who are not up on the attributes of the types of case pressure, it's not 'simple logic that will be missed'
...sorry you weren't intelligent enough to figure that out....
see how that works?

Ahh...I see. :haha: :rolleyes: