Fractal Design Define R5 Fan Setup

[PlugHerRightInTheSocket]

So this is the fan setup I'm currently thinking about using. The case fans Ill be using will be the stock GP-14's that come with the Define R5 + 1-2 more that I'm buying depending on your guys' thoughts. The heat sink will be the NH-U14S from Noctua, which comes with its own optimized fan (green)

Anyways I'm wondering if the 3rd bottom intake (purple) is over kill for positive air pressure since ill only have 1 exhaust + the force of the heat sink fan forcing air out the back.

 

 

I should add that the bottom fan isn't in the forward most position because that's where my HDD cage will be, unless you guys think it'd be better to have the fan in front and the HDD cage by the PSU.

[Andrew Storlie]

That is fine. Thats how i have my 450d set up, litterally exactly the same

[airdeano]

have you read this thread: http://linustechtips.com/main/topic/458258-define-r5-airflow/#entry6151341

[Jimmybiggs]

Yeap - My R5 has the same setup - planning the lower fan when I get an M2 drive (& system) due to the heat it produces.

 

I was just reading last night that the lower fan actually induces "turbulent" airflow, which is more productive than "laminar" airflow to cool chipsets.

 

ie. Straight flow speeds past like a racecar in a wind tunnel, vice, but doesn't "interact" with the heat "molecules" (bad word) as well as "turbulent" airflow.

[PlugHerRightInTheSocket]

have you read this thread: http://linustechtips.com/main/topic/458258-define-r5-airflow/#entry6151341

I haven't no, but I already understand the pros/cons to positive air pressure vs negative air pressure better than that thread has explained. Since the heat sink fan isn't exhausting directly out the back of the case I was wondering if it's worth while to have 3 intakes for the extra pressure since pressure should still be at least slightly positive even with only 2.

[Jimmybiggs]

I haven't no, but I already understand the pros/cons to positive air pressure vs negative air pressure better than that thread has explained. Since the heat sink fan isn't exhausting directly out the back of the case I was wondering if it's worth while to have 3 intakes for the extra pressure since pressure should still be at least slightly positive even with only 2.

I can only say that I run the same case with every fan as you've described (minus the bottom fan) - "positive pressure"

 

My system (1st Gen 130W CPU with the Hottest Northbridge Temps that Mobo's every had, thanks X58 - this is why they moved the Northbridge function to the CPU in Sandy Bridge, too hot). Again, my system is notoriously hot and this config dropped temperatures considerably.

 

Read this - http://www.designnews.com/author.asp?doc_id=232525&dfpPParams=ind_184,bid_272,aid_232525&dfpLayout=blog

 

This is why I'm going the Fractal Design GP-14 for front and bottom - exactly where you placed them in the original pic. They are High CFM fans, but not overly fast or ejecting air at a high rate/pressure. Exactly what the article is banging on about. I've read many an article which shows that too many fans make no big difference - but I do understand how turbulent air (90 degree fans) do, as it's all about physics of the air flow on the surface of chipsets - as the article explains. 

 

As I see it, the lower fan and front create turbulent air on the motherboard where it counts.

 

If you're super worried about too much positive air, get a Noctua Industrial Fan for the rear. To eject as much as possible, maybe even go 12mm fans on front and bottom - the case supports it and the case will be less "positively" pressured. You know the drill, back to the same argument, more fans vs. where.

 

Hope you're more empowered to make a choice that your happy with at the end of the day.

[RazrLeaf]

I have a Define R5 with 4 fans, arranged with 3 intakes and 1 exhaust. While you can get away with 2 in and 1 out, 3 in is better for multiple reasons.

1. The filters reduce CFM. They keep out dust, but make it harder for the fans to do their job
2. The stock fans don't have enough pressure to counter-balance the resistance of the filters. The filters drop their CFM considerably. I'm not sure 2 stock filtered intakes can match 1 stock exhaust.
3. "Too much" positive pressure will not hurt your cooling capabilities. It just helps keep dust out. The irony of PC air cooling is that the most effective fans are ones that move heat away from sources (exhaust), but those setups quickly become the dustiest (and therefore ineffective) unless regularly cleaned.

My recommendation is as follows: stock fan exhaust, stock fan as bottom intake (between PSU and HDD cage), and 1 or 2 more powerful fans for the front intakes. The door provides good noise attenuation for the more powerful intakes, and the stock fan can output close to it's max CFM as an exhaust. 

 

And I suggest you use the second stock fan as the bottom intake is because my bottom filter would vibrate against the case when I had a powerful bottom intake fan. The bottom filter is clipped at the front (under the HDD cage) and the back (under the PSU), but the middle isn't. And the filter is naturally curved away from the case. When I had a powerful enough bottom intake, it would pull the filter up flush with the case, but then the filter would bow away, then get pulled back, and create an annoying buzz.

[Jimmybiggs]

I have a Define R5 with 4 fans, arranged with 3 intakes and 1 exhaust. While you can get away with 2 in and 1 out, 3 in is better for multiple reasons.

1. The filters reduce CFM. They keep out dust, but make it harder for the fans to do their job
2. The stock fans don't have enough pressure to counter-balance the resistance of the filters. The filters drop their CFM considerably. I'm not sure 2 stock filtered intakes can match 1 stock exhaust.
3. "Too much" positive pressure will not hurt your cooling capabilities. It just helps keep dust out. The irony of PC air cooling is that the most effective fans are ones that move heat away from sources (exhaust), but those setups quickly become the dustiest (and therefore ineffective) unless regularly cleaned.

My recommendation is as follows: stock fan exhaust, stock fan as bottom intake (between PSU and HDD cage), and 1 or 2 more powerful fans for the front intakes. The door provides good noise attenuation for the more powerful intakes, and the stock fan can output close to it's max CFM as an exhaust. 

 

And I suggest you use the second stock fan as the bottom intake is because my bottom filter would vibrate against the case when I had a powerful bottom intake fan. The bottom filter is clipped at the front (under the HDD cage) and the back (under the PSU), but the middle isn't. And the filter is naturally curved away from the case. When I had a powerful enough bottom intake, it would pull the filter up flush with the case, but then the filter would bow away, then get pulled back, and create an annoying buzz.

Thanks... you explained it much better than I did. The extra "positive air"  is always a cooler setup

[Matacks]

I always go crazy with exhaust fans on my cases.. But I tend to use air coolers. Its just good because those top mounted fans will help pull all that heat away from a heatsink. I guess its not that important if you're using some type of water cooling.

My case has three exhaust fans ..two top one rear. When gaming or doing stuff to warm up the computer, I'll hold my hand over the top of the case. The whole area around the top and back of the case is dumping lots of heat. Its like a big toaster. I guess my case gets pretty dusty though.

Then again, your setup looks good. has plenty of positive pressure.