Suck or blow?
 

Apologies for the Daily Mail style subject! :D

Question - tower case with two fans - one at the back and one mounted on the top of the case. Which way should they be mounted?

My top fan is effectlvating sucking air out - when I hold a piece of paper over it, it blows away - if it was blowing air into the tower the paper would stick.

So which way should they be mounted?

Re: Suck or blow?
 

Depends where the other one is but I think having the top one as the extractor is correct.

http://www.tomshardware.co.uk/faq/id...uter-cool.html

Re: Suck or blow?
 

Intake and exhaust - I still prefer suck and blow!! :-)

OK - so rear intake (oh dear) and exhaust at the top - I think that's way they are configured so all good then.

Re: Suck or blow?
 

Do you not have a fan/s on the front?
My tower case has twin 80mm fans sucking air in, then as yourself 2 others exhausting.

Re: Suck or blow?
 

No - rear fan and top fan - oh and of course the CPU fan.

Re: Suck or blow?
 

i can't speak for your pc but i generally suck in at the top and blow out at the bottom :)

Re: Suck or blow?
 

I use 2 large front fans for sucking, whilst the rest do the blowing.

Re: Suck or blow?
 

Try and think about how air will move in the case. You aren't just cooling the CPU and even providing air to the GPU 's fan system, you need to move air over the motherboard and even your hard drives. Your PSU may also need air.

What are the points of entry to the case, even if they don't have fans. Are there vent grilles on the front and sides? If plenty of vents then your top and rear can probably both be exhaust as the air will get drawn in elsewhere. But if the front is effectively sealed then that rear fan should probably be an intake.

Some software can help you monitor temps on certain parts of your PC. That may help you find the best arrangement of fans, and their speeds.

Re: Suck or blow?
 

I saw a college experiment where different fan locations and directions could actually make "null" areas that caused overheating. And with modern hard drives, RAM, VRAm, etc. all preferring a cooler environment things could become very bad very quickly if the fan configuration was wrong.

Plus more air movement can equal more intake of airborne fluff and dust that could get trapped and thus cause overheating.

Most of the electronic equipment I used in the RAF had air filters, but I've never seen filters on PC's.:confused:

Re: Suck or blow?
 

You can get separate filters to mount with fans. http://www.overclockers.co.uk/produc...428&subid=2363

I've also had a coolermaster HAF 912 case that had front filters pre fitted, whilst many cases do at least have a fine mesh. Even so a periodic blowing out of the case inside can be a good thing.

Re: Suck or blow?
 

I have 1x120mm front & 1x120mm btm (both filtered) for intakes. 1x120mm top, 1x120mm rear 1x120mm side for venting.
Dependant on style of case is to whether its best you have positive or negative pressure within the case.

Re: Suck or blow?
 

Both rear and top fans should be blowing air out. Cases are designed for air to flow from front to back. Heat rises, so secondary flow is from bottom to top.

Re: Suck or blow?
 

Looks like I'm missing a few fans then. I'll have to get a couple of 120mm fans when I do the PC refresh .

Re: Suck or blow?
 

You don't really need a huge number, again unless you're excessively overclocking, modern processors are reasonably efficient and low-power compared to yesteryear's, plus your power supply will already have a (likely) 120mm exhaust fan. Processors (non-overclocked) don't generate any more heat these days than they did ten years ago, when they built PCs with a single 80mm exhaust fan.

I've a friend who has a micro-ITX case, full-power Haswell CPU, and a GTX 780 card with just two 120mm exhaust fans, and it stays pretty cool and quiet. That said, if you're using air filters it's useful to have additional intake fans due to the pressure differential.

Re: Suck or blow?
 

I think it's down to the sensitivity of the equipment to dust versus the amount of dust you expect to deal with. Aside from causing some cooling issues PCs don't mind dust, and the average home/office is usually reasonably dust free.

If however your dealing with high power radar/IT equipment that might be used in desert environments then filters are probably a necessity.

Re: Suck or blow?
 

I currently have 2 fans on the front of my case drawing air in, with 4 at the top on my H100i drawing air out, and a the rear fan is also drawing air out.

Both my GPU's draw air from inside the case and blow it out the back, which is why I have the rear fan blowing air out, as I don't want it drawing the hot air in from my graphics cards especially, as they are now working harder than ever with my new 4K monitor.

If you want good fans for just pushing air around your case then look at the Corsair AF fans and if they are noisy, put them on a speed reducer cable or grab some Noctua NF-P12's not cheap but very good fans.

Re: Suck or blow?
 

The corsair AF fans are great, recommend.
If you don't want to replace the fans and you find that there is noise generated by fan vibration then I recommend http://www.quietpc.com/afm03b-group?...9fnhoCOJrw_wcB

Just ordered 80 from Japan for £9.00 and they do work very well.

Re: Suck or blow?
 

Don't listen to Damien.....his case hovers half an inch off the floor when all the fans are running :D

---------- Post added at 20:20 ---------- Previous post was at 20:17 ----------

If you are looking for quiet fans then have a look here :)

Just a thought, if your machine had enough connectors for what you need then I think it's aerocool (and maybe some other manufacturers) do temperature controlled fans where the fan itself has a sensor and adjusts as it's needed, opposed to PWM where the motherboard has control. Not sure if they are molex connected or 3 pin.

Over the last 5 or 6 years fan technology has come on in leaps and bounds and it's very refreshing to see the art of moving air moving forward.
I had been out of the build loop for 5 years and the 3 machines I have built over the last month have all been quieter and cooler than what I thought was a quiet cool media centre we have at home. It's made me reevaluate the media centre and that'll be a new build in the next month or so with max airflow and main temps the main goal.

Re: Suck or blow?
 

No Rammy it does not, you will see how quiet it is at the next lan.

Also how it doesn't take off or hover, since I only have 7 fans in the pc now compared to my test bench which had 10, and my 900D which had 18, and the pc was always fairly quiet apart from benchmark runs.

Re: Suck or blow?
 

Lol, 18 fans. Did it look something like this: :D

https://www.cableforum.co.uk/images/...2014/10/13.jpg

Lol

Re: Suck or blow?
 

Wouldn't the PSU require extra fans to deal with the current that lot drew? ;)

Re: Suck or blow?
 

18? Now that is impressive.

I currently have about 11 fans (2 fans on my TRUE Spirit 140 CPU heatsink hence the edit), including PSU, HSF and Graphics card fans in my current rig. Generally, I have the philosophy of in at the front and side, out at the back and top. So air comes in cool, goes through the "hot bits" of the PC and goes out hot. Not sure if it works 100% effectively but my GTX 780 peaks at around 65c, and my CPU, clocked at 4.3Ghz currently (An i5 2500K) tops out at 60c on stress tests and much lower in general use.

All of my fans are controllable too though. The case has a fan controller and the main CPU fan has an external controller, the rest are software controlled aside from the PSU which is quiet). In winter/Netflix use I shut off all the fans I can and turn the rest to minimum so my PC is as close to silent as possible.

Re: Suck or blow?
 

That's not a benefit. The point of the fan is to cool the motherboard, not itself, so it's the motherboard temperature not the fan's temperature that's important. It's useful (marginally) only if you don't have controllable outputs on your motherboard, but even then a splitter on the CPU output is a better idea.

---------- Post added at 12:12 ---------- Previous post was at 12:12 ----------

Not if you had a decent PSU. 80mm fans use 1-2w each.

Re: Suck or blow?
 

I have a 140 mm at the front sucking air in and a 100 mm fan on the
Scythe Shuriken Rev B Quiet Low Profile CPU Cooler on a Intel I5-3570K CPU, 120 mm sucking out at the top and a 120 mm at the rear sucking air out and a 90 mm on the video card there is a fan in the PSU but that only coolers the PSU.

CPU 27degrees C, MB 24 degrees C

Re: Suck or blow?
 

Not far off that. It was a sight to behold :D

Re: Suck or blow?
 

:D I think you would need to bolt your computer down with all those fans. :D

Re: Suck or blow?
 

Nope. Computer fans have pathetically low static pressure verses anything that comes close to being able to lift itself, let alone a computer with it.

Re: Suck or blow?
 

I'd have thought that by the time you hit more than six case fans water cooling starts to make the most sense?

Re: Suck or blow?
 

Depends what the fans are doing really. Water cooling starts to make sense when you have very high total heat output concentrated over small areas and/or restricted airflow. IMO, when you're dissipating more than 200w per square foot, then you want water cooling.

Re: Suck or blow?
 

There was actually more than 18 fans, when I think about it properly but every fan was quiet and the whole pc, made barely any noise.


Fans were laid out like this in the 900D that I had.

Rear: Akasa Apache Black - Extract
Top: 480mm rad with 8 Akasa Apache Blacks in push/pull - Extract
Front: 3x Akasa Apache Blacks - Intake
Front HDD Cage: 1x Akasa Apache Black - Intake
Bottom Left Side: 360mm rad with 6 Akasa Apache Blacks in Push/Pull Intake
Bottom Right Side: 240mm rad with 4 Akasa Apache Blacks in Push/Pull Extract


The noise level from that pc was about the same as from a pc with only 2 fans in it, as the fans that I chose the Akasa Apache Black have a really low noise level as they only, run at 1300rpm.

That was cooling my 3930K at 4.6ghz, Rampage IV Extreme and 2 GTX 680's all overclocked.

Re: Suck or blow?
 

iirc with the Corsair sealed watercoolers they try and have you believe that the air ingress should be through the rear panel where you install the radiator(s).

But sod that, I would never have warm air blowing back over the motherboard even with a top exhaust.

Re: Suck or blow?
 

The default configuration on all Corsair sealed watercoolers is to blow hot air out of the case at the back through the radiator. None of them are configured for ingress unless you modify them yourself.

Re: Suck or blow?
 

Not really a problem as you can just reverse the fans either side of the block...once you've replaced them of course due to the stock one being so darn noisy.

Re: Suck or blow?
 

Personally I'd just buy a cheaper, quieter one to begin with instead of wasting money on an over-hyped POS and then wasting more money to quieten it down again.