Fan arrangement question

**drdoom** · 10-23-2003, 10:52 AM

Ok I got one of those X-Dreamer cases. I has two front fans slots, two rear, one top, and one on the side window. I wondering what the best arrangement to maximize the airflow. I was thinking about have the two front intake and the two rear exhaust. Then the top exhaust and the side as an intake.

**BlueOval** · 10-23-2003, 11:20 AM

The way I'd do it is use the 2 rear exhausts, use the 2 front intakes, use the top as a blowhole exhaust, and seal off the side completely. But you could experiment - try using the 2 rear exhausts and 1 front intake first - sealing off the top and side. Place it under load for a while then check your temps. Then add another front intake, place it under load, check the temps... you get the idea.

**drdoom** · 10-23-2003, 01:51 PM

Why seal the one on the side window? The case has a thermometer so I could try a couple of arrangements and see.

**{WP}_Gedron** · 10-23-2003, 02:16 PM

I believe, correct me if I'm wrong Blue, that he was refering to making sure the side itself (around the edges) is air tight. Generaly speking making sure air is only getting in/out where you want it to.

**BlueOval** · 10-23-2003, 03:11 PM

You were both right and wrong {WP}.

Yes, I was referring to making the case airtight. I should have added to ensure that the back of the case is sealed off as well - like where you remove the small aluminum panels for add-in cards. But I also meant to say to completely block off the side hole as I've never found any real benefit to adding a side fan.

I tried one with my case - an Antec 1080AMG - both blowing air in and blowing out. I've heard it said that depending on the location of the side hole - be it over the CPU or over the vid card - you should have it blowing in or blowing out. But I can never remember which is which. lol

So, really what I meant was.. seal off everything completely except the 2 rears and 1 front (on the bottom) at first and check your temps. Then add 1 fan at a time, always checking your temps, until you find the right combination for you.

You don't want to necessarily buy 6 fans all at once and install them all, because you may find that you just can't stand that much noise! Besides, without experimenting, you'll never know for sure which combo produces the lowest temps at a noise level you can tolerate.

Hope that clears it up for ya'all and sorry I wasn't clear in the first place. :\

**irwincur** · 10-23-2003, 04:02 PM

Side blowholes suck for airflow, they create a lot of turbulence in the front to back stream. Another thing to try that has helped my temps. Put the side with the blowhole on the opposite sode of the case, behind the motherboard and CPU. I found that this lowers my CPU temps by almost 3C. But for this to work you need strong negative pressure in your case, or more air leaving than entering. This is the preferred method anyway.

**BlueOval** · 10-23-2003, 04:06 PM

Originally posted by irwincur
...But for this to work you need strong negative pressure in your case, or more air leaving than entering. This is the preferred method anyway.

Which is why I suggested starting with 2 exhausts and 1 intake working towards 2 rears, 2 fronts and the top blowhole exhaust.

**mikead_99** · 10-23-2003, 07:22 PM

irwincur:

Side blowholes suck for airflow, they create a lot of turbulence in the front to back stream. Another thing to try that has helped my temps. Put the side with the blowhole on the opposite sode of the case, behind the motherboard and CPU. I found that this lowers my CPU temps by almost 3C. But for this to work you need strong negative pressure in your case, or more air leaving than entering. This is the preferred method anyway.

In general I agree. My wife's machine has a pretty cheap case that only allows 1 bottom front intake, 1 rear exhaust as well as PSU exhaust(of course), but came with a side panel fan mount. I put an 80 mm Stealth (low CFM) in the side and got a really nice drop in temps that way. Because of the limited exhaust I only used a Stealth in the front too with a CM 80 in the rear and the PSU is an Enermax with 2 90's. I adjusted the PSU to medium speeds and I think I got lucky with the right amount of negative pressure, low turbulence, with such low volume exhaust.

After all that, that is the only good experience I've had with side intake fans. For myself, I try to make sure the case I'm going to buy does not have them at all, but I never tried putting the panel on the other side either.

**CrawlingEye** · 10-24-2003, 12:46 AM

Originally posted by irwincur
Side blowholes suck for airflow, they create a lot of turbulence in the front to back stream. Another thing to try that has helped my temps. Put the side with the blowhole on the opposite sode of the case, behind the motherboard and CPU. I found that this lowers my CPU temps by almost 3C. But for this to work you need strong negative pressure in your case, or more air leaving than entering. This is the preferred method anyway.

I agree and disagree.
Side fans are great, if you have them placed well and they're NOT blow holes.

I have a 92mm Tornado above my 80mm Tornado on my hsf.
The side fan works as an exhaust. I have it slightly offset from the Tornado which is a bit back and higher than the 80mm on the hsf.
It functions very efficiently, both sucking out the hot air pulled off of my cpu and as a general case exhaust.

I will note this though: I have my 80mm tornado on the hsf sucking air off the hsf itself.

Frankly, I would go with two medium (sunon 50CFM?) powered intakes in the front, 2 relatively higher powered exhausts in the back, perhaps a medium powered larger fan intake on the top (120mm?) and a nice exhaust on the side, providing your setup is similar to mine.

The idea for the top intake could be reversed, but frankly, I think it'd be more efficient as being a larger fan, either way you go. A larger fan will be less likely to disrupt airflow throughout the case, where-as littler fans that are more powerful are way more prone to disrupting airflow.

**kusojiji** · 10-24-2003, 06:51 AM

This is what I did. I have a FS020 with three 120mm fans, one in the front blowing in and the two in the rear blowing out. All fans are on a fan bus. Even with the fans blowing at full blast (300cfm rear, 80cfm front), the temps still remained high. I ended up turning one of my rear fans around and ducting it directly over the processor. Temps went down dramatically.

**purplexed** · 10-24-2003, 02:38 PM

I use a case I made myself wich is just 2 plexiglass sheets . since it's all open it didn't make sense to me to make an airflow from the front to the back, so my airflow is all from the side, and it works very well, I think even better then any closed case, because I have the same airflow with nearly all my fans put on 5 V, so the noise is quite low.

I have all 80mm Noiseblocker fans, one on the cpu heatsink, the other directly above this, so it pushes fresh air for the other fan. this 2nd fan lowers the temp of 5 degrees.

then I have one on the side, for the harddisk (I cut openings on the opposite side for the exaust air), and one on the side to blow on the gpu heatsink ,wich is fanless.

I agree that the fan on the opposite side of the motherboard helps a lot, it can lower the cpu temp of another 5.

**drdoom** · 10-26-2003, 11:29 AM

You don't want to necessarily buy 6 fans all at once and install them all, because you may find that you just can't stand that much noise! Besides, without experimenting, you'll never know for sure which combo produces the lowest temps at a noise level you can tolerate.

I was thinking about getting some of those neon Coolmaster fans form newegg. They are only 25db and when you get 10 they are only 4USD delivered. One is 7.50USD. Plus I can alway keep the extras for the next computer

. Any thoughts on those fans they are not really high airflow but 25db is pretty quiet for standard fans.

**gkline** · 10-26-2003, 08:32 PM

I love my Panaflos!

**BlueOval** · 10-27-2003, 12:48 PM

25 db is fairly quiet yes, however the lower the amount of noise generated, the lower (generally) the output of air. You need to take a look at how much cfm the fans you are thinking of getting put out. I echo gkline by saying I love my Panaflos.

**drdoom** · 10-27-2003, 03:14 PM

Originally posted by BlueOval
25 db is fairly quiet yes, however the lower the amount of noise generated, the lower (generally) the output of air. You need to take a look at how much cfm the fans you are thinking of getting put out. I echo gkline by saying I love my Panaflos.

Newegg list them at 2500rpm and 32CPM. The 80mm Panaflos are listed at 21db and 24CFM.

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