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How to decide on a case for air cooling (warning - pics)

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#1 ·
When you are going to cool your cpu with a heatsink, what case should you get?

I have come to believe that forming a wind tunnel, with my cpu cooler in it, will give me the best cooling. So I want a case where I can make a wind tunnel. I looked at this video:


It gave me some great ideas, especially about positive pressure. But I noticed that the single large top fan simply added air. OK, the cpu heatsink was able to use it, but the fan's input did not contribute to the flow of the air.

I also noticed that the rear fan space was a window, not a grill. The air left the case freely. This is good: no pressure buildup in the case, no noise from an exhaust fan.

So, a case I would want to have would have room for two case fans in the top. That way I could block off the rear top position and use the forward top position as an intake, like this:

Beta_Evo_quiet_rig_2011-05-30_009.png


Well, that's not bad, but ideally the forward top fan should clear the front of the heatsink. The case is an NZXT Beta Evo, a mid-tower case, relatively compact. More ideal would be the HAF X, with two 200mm fan positions in the top. The forward top fan clears the front of the cpu heatsink in that case:

6.jpg?223981851


So, we want to be able to put air into the case. If we do it right our "positive pressure" will be just enough to move air in the case. We will want to bring in air from many directions to avoid spots of stagnant air that will heat up and warm our case contents.

We want to avoid negative pressure, since that turns our case into a vacuum cleaner with no bag and lots of little unfiltered places the air goes in. We end up with unending dust.

I would suggest avoiding the bottom-up airflow of old. That method was good when the motherboard components got hotter than the cpu. Now they get warm and sometimes hot, but not hot enough to need lots of airflow to cool them. However, bringing air up over those components allows them to warm that air, and it is this warmed air which then gets ingested by the cpu heatsink. That compromises cpu temps. People who have converted from top exhaust to top intake have seen 3 - 5c temp drops, just from changing the direction of their airflow. Hot air will rise unless it is directed elsewhere. Air goes where you push it.

So, top intake. What else? Front intake.

Upper front intake can be had by putting a fan in your 5.25 cage. Here's a thread on it. If you have three 5.25 slots you can put in a 120mm fan. If you have four 5.25 slots free you can put in a 140mm fan. It will require that your case will have mesh covers for the 5.25 slots, preferably with filters in them. Many cases already do this as they anticipate negative pressure airflow.

Lower front intake fans should be as wide as possible. I like the idea of 230mm fans: the bigger the diameter the slower the fan can go for a given output, and thus the quieter it will be.

Bottom intake: I'm not convinced that these help with a forward-to-back airflow. Need more data on this. More cooling results.

Side panel: the bigger the better - wider fans run more quietly. OTOH, if the fan is too wide it can interfere with a tower-type heatsink.

Rear fan: The ATCS has a box you can put on the back of the case that will pull air from the slots in the backplane. That's nice, but most of us get cases with a rear grill and exhaust fan.

If you think about it you will see that your exhaust fan needs to overcome the grill behind it. And it will also need to move enough air to keep up with your intake fan. Since most rear fans are 120mm things, they will need have a substantial output, which means they will be noisy. You can begin to see why I advocate removing your rear grill and rear fan, or buying a case with no rear grill in the first place.

You don't need a rear exhaust fan if you have no rear grill. If you use a pull fan on your heatsink, that fan will entrain case air and exhaust you case by itself. Don't believe me? Look at item 2 in my sig. I was able to create a negative pressure case with only the fans on my heatsink.

When I was done, I had created this airflow:

Beta_Evo_Quiet_Rig_02.png


Note that I also removed the backplane slot covers. My next mod will be to remove the pillars between the slots to make the whole backplane one empty space.

So what are we air coolers looking for in a case?

In standard cases, look for wide cases. No narrower than 200mm. This allows for full tower heatsinks and room behind the mb for cables. Actually, any case with a 120mm exhaust fan will most likely handle a full tower cooler (they are 155 - 160mm tall). But a 7.5-inch case, for example, will hardly have any room behind the motherboard tray for managing cables. My 200mm-wide Beta Evo, for example, has room for a full tower cooler and just enough room for managing cables.

In standard cases, look for two top fan positions. This allows you to use the front top one for air intake: cool air directly to the heatsink. Block off the rear position.

Mesh slot cover in the 5.25 bay.

Unfettered access for the main front intake fan. No plates or fancy covers that block the air.

Side panel intake fan.

Case fans as large as possible to be able to run them slowly and thus quietly.

Good cases: CM 692. CM HAF series, especially HAF X.

Raven; FT02. Note that these are non-standard cases that would have front-to-back airflow if they were oriented in a standard manner.

Edit: adridu59 brought the Zalman Z9 Plus to my attention. It's wide enough: 8.13 inches / 207mm wide - very important. It has capacity for 140mm fans: 1 in front, 1 on bottom, two on top and one in the 5.25 bay (behind the IO panel). The side panel can handle a 140mm fan, too, if you use a fan that has 120mm screw holes. I like the mesh sides of the HD cage. All in all, an excellent case, and inexpensive.

Edit: greenhold brought the Azza Hurrican 2000 to my attention. I just researched it. It fits the above criteria. According to this review there is a lot of room behind the mb tray. There are plenty of fans, and provision for a bottom intake. Although you would think from looking at the case from the front that it is much skinnier than 10 inches (its stated width:

hurrican2000_i.jpg


it does have 230mm fans in the top:

azza-hurrican-inside-top.jpg


(from this review)

So, it looks promising.

Edit:

solsamurai suggested the NZXT Tempest Evo and the Fractal Design Arc Midi Tower. Both seem to be excellent choices for air cooling. I am especially excited about the Fractal Design case.

Rosewill Blackhawk looks promising, if a bit pricey.

Edit: Corsair Vengence C70 looks very promising.

Avoid Antec, except for the DF-85.

There are Lian Li and other high end aluminum cases that have no grill at the rear. This is best, because you can allow the air to simply flow out. No noise, no pressure build up.

Avoid negative pressure cases: they are vacuum cleaners without the bag.

So, sit down and think about airflow before you buy a case. Do your homework. Don't be in a hurry. Good things come to those who wait.

Further thoughts: please add more below.

Found a good case for air cooling, the Lian Li PC-90. A review here.

175

Product page.

BTW - if you're wondering why I went with the Beta Evo, it's because that case is the best airflow case that can fit in the space I have available. As it was, I had to move the shelf above it up an inch to get decent air clearance.
 
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#2 ·
didnt I see this thread already?
headscratch.gif


good guide though
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#3 ·
Quote:
Originally Posted by pangeltveit;13870429
didnt I see this thread already?
headscratch.gif


good guide though
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I put it together as a thread because we have discussed it many times in other thread. The topic deserves its own thread.
 
#5 ·
Quote:
Originally Posted by audioxbliss;13870963
What's weird is, the forward-most top 140mm on my P193 DOES clear the push fan on my Mugen 2, if just barely. In my friend's Beta Evo, the measurements seem almost identical. No idea what happened.
What motherboard is he using? The cpu position differs on different mb's.
 
#7 ·
Antec cases arn't all that bad. I can do the EXACT same thing except for the top front intake fan. I can even have 3 front intake fans, whereas the Beta Evo has 2.

Speaking of which... should the top rear fan be intake or exhaust? in that video you linked they had a top rear only fan, and it was set to intake.
 
#8 ·
Very interesting

But i find i am usually always doing something to my pc within 6mths 12mths, i just get the compressor on to it and its perfectly clean again. But it really only needs a clean every 12mths, i guess it already has a positive pressure, if the fans are set right

My case VH6000BWS not the new smaller case VH8000 rubbish case, its fully grated at the front, I added a fan below the burners, still got the one below the hd's, plus you got the big side fan noisy turbine that i got running only at 800rpm to quiten the beast, its the only stock side fan, but all other fans i threw in the bin and replaced with new ones. The top fan is blowing in pressuring it more. To me i couldn't live without my VH6000. Could be the case you need?

Oh i tested mine ages ago with a mates bee-smoker(they use em calm the bees with), that guy has a better smoker to me, but after doing that my pc, it smelt of smoke for weeks
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#9 ·
Quote:
Originally Posted by Tigerpaws;13874164
Very interesting

But i find i am usually always doing something to my pc within 6mths 12mths, i just get the compressor on to it and its perfectly clean again. But it really only needs a clean every 12mths, i guess it already has a positive pressure, if the fans are set right

My case VH6000BWS not the new smaller case VH8000 rubbish case, its fully grated at the front, I added a fan below the burners, still got the one below the hd's, plus you got the big side fan noisy turbine that i got running only at 800rpm to quiten the beast, its the only stock side fan, but all other fans i threw in the bin and replaced with new ones. The top fan is blowing in pressuring it more. To me i couldn't live without my VH6000. Could be the case you need?

Oh i tested mine ages ago with a mates bee-smoker(they use em calm the bees with), that guy has a better smoker to me, but after doing that my pc, it smelt of smoke for weeks
frown.gif
That's why I'm happy to leave smoke tests to Silverstone.
 
#13 ·
Quote:
Originally Posted by TC_Fenua;13874411
Nice write up
smile.gif
If only I had this several months ago, haha.
Positive pressure is the way to go, I discovered that on the Silverstone website in their "Tech Talk" section, very informative.
You can check my build log to see my experiments with air cooling
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Great shots. I haven't had time to read the text yet.

That shot of your D14 over your Dominators is sweet. Please post it in this thread.
Quote:
Originally Posted by philologos;13874639
Any thoughts on the CM ATCS 840?
Interesting case. Will revisit after work.
 
#16 ·
Quote:
Originally Posted by philologos;13874639
Any thoughts on the CM ATCS 840?
Had to re-familiarize myself with that case.

It's about the most flexible case for airflow, but I'm not enamored with the plate covering the lower intake fan. There's lot's of room, though, for a 5.25 cage insert to put in a supplemental intake fan. Lots of room to play in, and you have that fan housing that goes in the back to pull air across your graphics cards. Overall, a good case.
 
#22 ·
I don't see why you do not recommend Antec cases. Do you have actual scientific reasoning on why you would put an entire brand to the backburner despite its popularity?

My Antec 900-2 is an amazing case. It's technically a negative pressure case~ but has a ton of ways for me to get air into it. It's virtually the same as your case. I don't get a massive abundance of dust. I don't even know where you're getting this from.

The idea of it being a vacuum cleaner without a bag sounds catchy and nice on paper, but in practice this isn't true at all. My entire case is a wind tunnel.
 
#23 ·
Antecs aren't the easiest to work with. Build quality is decent, but really, that's about as far as they go. With my P193, the wire management is horrendous (and was the same with my old P182 and my friend's 1200) not to mention there's far too little space between the mobo tray and the side panel, making wire tucks that much harder. And when you can't hide those cables away, they end up blocking air flow. Very few of their cases have dual top fans, meaning it's harder to get appropriately fresh air pushed to the CPU cooler.

I'm willing to work with my case, and I'm starting a hefty mod project next month to fit my water cooling, so it works for me. Most likely I'll go with a different company for my next case, though. This P193 is just too much of a PITA, especially considering how much easier everything was on my friend's Beta Evo and my other friend's HAF 932.
 
#24 ·
Quote:
Originally Posted by audioxbliss;13971322
Antecs aren't the easiest to work with. Build quality is decent, but really, that's about as far as they go. With my P193, the wire management is horrendous (and was the same with my old P182 and my friend's 1200) not to mention there's far too little space between the mobo tray and the side panel, making wire tucks that much harder. And when you can't hide those cables away, they end up blocking air flow. Very few of their cases have dual top fans, meaning it's harder to get appropriately fresh air pushed to the CPU cooler.

I'm willing to work with my case, and I'm starting a hefty mod project next month to fit my water cooling, so it works for me. Most likely I'll go with a different company for my next case, though. This P193 is just too much of a PITA, especially considering how much easier everything was on my friend's Beta Evo and my other friend's HAF 932.
This. Every bit of this.
 
#26 ·
Quote:
Originally Posted by iCrap;13972766
I'm going to re-mod my 300. Adding a bottom, and top front fan. Also cutting cable management holes. THEN my Antec will be somewhat decent
smile.gif
Yay! I'll be cutting a massive hole in the top of my case to fit a Koolance shroud and a 360mm rad, then chopping/expanding some holes in the motherboard tray. If I could figure out a way to give myself more room behind the tray, I'd totally do it.
 
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