Extra fan, how and where?

[Jokerstyle]

I recently built my system, and it's been running for about a week. Everything works great performance-wise, but the noiselevels from the fans are really high.
I have the smart fan-control activated in BIOS, so the initial fan noise is very low, albeit after half an hour tops the speed and noise will have taken a drastic turn for the worse.

The temperature in itself is not all that bad, according to SpeedFan the temperatures oscillate between 39 and somewhere around 45-50(-isch) degrees.

This is a (bad) sketch of the current airflow in the computer and some of the key components. I only have the fans that came with the different components, e.g. the CPU, GPU and PSU fans. There is no extra fan at the moment. Both sides of the chassi are attached. The HDD is the hottest component in the build, and has a constant 3 degrees lead over all other temperatures.

Thats the basic idea of it all, I'm guessing it would be a good idea to add extra fans, but the question is how many and where? Also, should they blow air in or push it out? I'm doing this to combat noise levels, does this mean bigger fans are better due to lower RPM?

Thanks in advance,
Jimmy


edit: Specs are:
AMD Phenom II X4 955 Black edition. 3.2 GHz
ATI Radeon HD 5850
4 gig DDR3 RAM.
The computer is not overclocked.

 

[MadAdmiral]

So you don't have any fans on the case at all? That's not a very good idea. Heck, I can't even think of a case that comes without fans...

At the very least, you want an intake fan in the front bottom (in front of the GPU) and one in the back top. Basically, you want to replicate the traditional way cases are built. Take a look at the cases on Newegg, particularly some of the higher rated ones (anything from Antec, Coolermaster, NZXT, Lian Li).

 

[WR2]

You didn't mention the case (chassis) you're using.
A quiet 120mm case fan or two is what you want to be looking at.
The classic cooling configuration is front low air intake and rear top exhaust.

 

[Jokerstyle]

Link - Press the "Fler Bilder"-tab.
It's a Deltaco Miditower, it's about as cheap as they come.
The classic cooling configuration indeed sounds promising, yet I'm not entirely sure what to do considering the compact chassi i got. There is space available on the back for a fan, but the front is quite occupied with the powerbutton and USB-ports.

I should add that the HDD is installed right behind the bottom removable flap. (The one right above the power button).
Is it advisable to modify the chassi side and attach the second fan there?

 

[MadAdmiral]

Do you have anything in the top three external bays? If not, I'd look into modding that part of the case to fit a fan. If all three are empy, it might fit a 120 mm fan. If only two are, then you're probably looking at an 80 mm fan.

Definitely put a fan in the back. That'll help a lot already.

 

[WR2]

Before you even think about modifying the case I think you should try a single case fan at the rear of the case. Set it up to exhaust warm air from inside the case. There should be some cool air intake from the front of the case with a medium CFM flow 120mm fan.

Hopefully the noise of the PSU, CPU cooler and GPU cooler should subside.

 

[MadAdmiral]

Agree. Next time, avoid this whole problem and buy a decent case. There are cheap ones out there that still have great cooling.

 

[Jokerstyle]

Thanks for the fast input, I'll heed your advice and install a 120mm fan in the back right away, and see how it goes from there.

And yeah, there is no question about it - I will invest more money in cases from now on. Besides the cooling, there were a dozen other problems to deal with during the hardware installation process - I had to make a ton of small tweaks, from installing everything in an awkward order to bending the structure in places to allow the GPU to fit. It's like the case was designed to "almost fit, but not really".

 

[Jokerstyle]

I've installed an extra fan now, but the results are grim.

the chassi was so small it only had room for a 80mm fan at the top back, so i modified the chassi and installed a 140mm fan at the side top back position. The reason being i wanted to go bigger than 80mm and this was the place closest to the original location.

Anyhow, im getting strange readings from SpeedFan. If I'm idling my computer or using software like photoshop, the temperature is a rather constant 35 degrees, at most, which I'd say seems rather okay.
If i start a game, the temperature rockets and withing a mere minute or so I'm up to my elbows in heat. The Temp2 shows about 50-52 degrees and the Core temperature reaches 60 degrees. Again, this happens usually ~30 seconds after the game has started.

If I then turn off the game, temperature then plummets in a similiar fashion and within a minute I'm back at 35 degrees. Is it really possible for the temperature to fluctuate this much this fast? One would think if a computer suffers from bad cooling, the ambient temperature should also be abnormally high.

I just started my computer after it'd been off all night, and the CPU/HDD temperatures were normal, CPU 30 and HDD 27 C, but the core temperature was a whopping 45 degrees. Is it even possible that the core temp is so abnormally high after the computer has been turned off for 10 Hours, or do you reckon it's a faulty reading?