More air blowing IN or OUT?

[H0RiZ0N]

Antec 300 case. 2 x 120 mm fans in the front blowing air into the case. 1 x 120 mm fan blowing air out the back. 1 x 140 mm fan blowing air out the top.

I just bought another 120 mm fan for the side panel. My question is...should I have that fan blow into the case and onto the video card(s)/mobo or should I have it blowing air out?

[ferrari12508]

Have it blowing in. Top always blows out, front always in, rear out and side in. Just the way it is. Also, if more is pushing in, it will force air out of the cracks in the case and if more it going out it will create a vacuum sucking air in those cracks.

[CaligulaPwns]

See which way it performs best in your case.

Negative vs Positive pressure is a debate that will never be solved. I always have more going out than in. I dont buy that BS about less dust and positive pressure. More exhaust will also tend to minimize hot spots in the case.

[Destiny]

Originally Posted by ferrari12508

Have it blowing in. Top always blows out, front always in, rear out and side in. Just the way it is. Also, if more is pushing in, it will force air out of the cracks in the case and if more it going out it will create a vacuum sucking air in those cracks.

Always is incorrect. Most of the time would have been the right word there Some cases are designed to make the best use of fans blowing in other directions... for instance, when the PSU is at the bottom of the case and you have a top fan in front of your CPU cooler's fan... cool air goes right into it, then exhausts out the rear fan.

Originally Posted by CaligulaPwns

See which way it performs best in your case.

Negative vs Positive pressure is a debate that will never be solved. I always have more going out than in. I dont buy that BS about less dust and positive pressure. More exhaust will also tend to minimize hot spots in the case.

Agreed. Try both, see which works best. Most of the time, having it push air in will keep the vid card cooler.

[Mind_Reader7]

More air going out will actually give you air flow. More air going in will just result in the hot air being pushed around in your case, as it has longer before it leaves.

[Almost Tactf]

Negative pressue FTW, I always have more exhaust then intake and I try to keep it within 10-15CFM of one another

[Technophobe_]

Originally Posted by Mind_Reader7

More air going out will actually give you air flow. More air going in will just result in the hot air being pushed around in your case, as it has longer before it leaves.

Exactly what I found with testing too.

[SKJT]

The side panel fan should be blowing in. I don't really care about the high/low pressure thing. I have strong fans all around my case and it hasn't given me a problem

[w7bj]

Originally Posted by CaligulaPwns

See which way it performs best in your case.

Negative vs Positive pressure is a debate that will never be solved. I always have more going out than in. I dont buy that BS about less dust and positive pressure. More exhaust will also tend to minimize hot spots in the case.

+1. And telling us the physical size of your fans isn't saying much. What volume of air are they moving? A 200mm fan moving 30cfm doesn't compare with a 100mm moving 80cfm. Also, the case design itself is a contributing factor, which is why "always" isn't always always. That little ditty hurt my head. But have fun.