Top Mount Rad - Intake or Exhaust fans?

[Nasha]

Hi guys,

Looking for some external input on this one, because i cannot convince myself which way i should go. Gut says exhaust because that's generally what you do at the top, but logic says 'you're pushing warm air over your rads nasha'.

So let me know your thoughts and reasoning, i'd love to hear what people have to say!

Cheers,
Nasha

 

[GlacierNine]

Exhaust. The air temp in your case will, overall, simply not be enough different to really worry about it.

 

[Nasha]

Exhaust. The air temp in your case will, overall, simply not be enough different to really worry about it.

Thanks for your input! I was always leaning towards 'my gut' with exhaust, but wanted to see if i could stir up some thoughts otherwise

 

[Bandalo]

Hi guys,

Looking for some external input on this one, because i cannot convince myself which way i should go. Gut says exhaust because that's generally what you do at the top, but logic says 'you're pushing warm air over your rads nasha'.

So let me know your thoughts and reasoning, i'd love to hear what people have to say!

Cheers,
Nasha

The important part is to try to balance intake and exhaust. So if you've got 2 fans on intake, have 2 on exhaust. Or, if you want to keep the dust out, have a little more intake than exhaust.

Other than that, it kinda depends on where your case sits in the room. If it's under a desk, you may want to pull in air from the front and send it out the top vice the other way around. If it's on top of a desk or table, then intake through the top and out the front/back might be better.

 

[Nasha]

The important part is to try to balance intake and exhaust. So if you've got 2 fans on intake, have 2 on exhaust. Or, if you want to keep the dust out, have a little more intake than exhaust.

Other than that, it kinda depends on where your case sits in the room. If it's under a desk, you may want to pull in air from the front and send it out the top vice the other way around. If it's on top of a desk or table, then intake through the top and out the front/back might be better.

I guessed that might be the case - As long as i was bringing in air from somewhere then it shouldn't effect too temps too much. Given that i'll likely have 2x 360's exhausting on the top, a 140mm exhausting out of the HDD area, the PSU exhausting, i need something a little more than the 200mm front intake fan then, because that doesnt balance out well!

 

[Bandalo]

I guessed that might be the case - As long as i was bringing in air from somewhere then it shouldn't effect too temps too much. Given that i'll likely have 2x 360's exhausting on the top, a 140mm exhausting out of the HDD area, the PSU exhausting, i need something a little more than the 200mm front intake fan then, because that doesnt balance out well!

Yeah, if you have negative pressure (more exhaust than intake) you'll have two problems...one, you'll suck dust into every crevice and crack of the case. Two, you'll have far less efficient airflow on the exhaust fans.

 

[Nasha]

Yeah, if you have negative pressure (more exhaust than intake) you'll have two problems...one, you'll suck dust into every crevice and crack of the case. Two, you'll have far less efficient airflow on the exhaust fans.

My case is practically honeycomb! Glad you mentioned the balance principle before i installed the new rads. Mind you, how do you balance out 7 120mm fans, when there simply is not enough fan mounts to even it out? Would you suggest in this case that i run one rad in exhaust, and one in intake?

 

[Bandalo]

My case is practically honeycomb! Glad you mentioned the balance principle before i installed the new rads. Mind you, how do you balance out 7 120mm fans, when there simply is not enough fan mounts to even it out? Would you suggest in this case that i run one rad in exhaust, and one in intake?

There's nothing wrong with setting up rads like that. I have a 280 on intake in the front of mine, and a 360 on exhaust on the top, then another intake on the rear. My water flow is to the 360 first, which gets most of the heat out of the coolant, then to the front 280 to cool it a last bit with the colder intake air. There's lots of ways to arrange things, but in general, to keep the dust down, have more intake than exhaust (positive pressure). So in your case, I'd try to arrange 4 intake and 3 exhaust.

 

[Nasha]

There's lots of ways to arrange things,

This just sent off a light bulb in my head! Flow to top exhaust, then to front intake. Brilliant!