Fan direction??

[richgtfc]

This is probably a stupid question, but I've 2 60mm fans on the back of my HTPC, should they be blowing air into the case or sucking air out of the case..... There's a great big 120mm fan on my QTechnology power supply which sucks air out and also a Zalman CNPS7000 CPU cooler as well. My system idles about 40-44degC, but the 60mm are constantly running at 2800rpm and are a bit noisy.

Cheers
Rich

 

[KraGorn]

Generally you want a flow of air in at the front and out of the back, if you suck air in from the back then you can get local flow out through the PSU and so components on the front, ie. disks etc., can get caught without a flow of air over them.

If you want to slow the fans you can get voltage adjustors, either fixed or variable, which can slow them down, albeit obviously with a reduced air flow. IMHO you really want 80mm fans for cases, 60mms are going to be noisier to obtaint the same air-flow in cubic-feet/min.

 

[richgtfc]

Thanks for that. I've just bought one of those Accent HTPC cases and it's only designed for 2 60mm fans at the back There are slots underneath the case, but no space for fans at the front. I've just stuck my fingers in the fans and they are the noise offenders. I think my motherboard has a smart fan thing I can enable in the bios, maybe I'll try that.

BTW the case looks fantastic (cool blue LED at the front and space for a VFD).

 

[KraGorn]

Ah sorry, didn't realise this was an HTPC and therefore shallower than a normal desktop, I guess 80mm fans won't fit. In that case you could try the speed adjusters if you want ... or perhaps some quiet 60mm fans perhaps. I use the 80mm version of these and they are a lot quieter than standard ones.

 

[mjn]

i have 120mm fans and they are erm.....noisy, but reduce my internal temp down to 16 degrees!!

 

[KraGorn]

Originally posted by mjn
i have 120mm fans and they are erm.....noisy, but reduce my internal temp down to 16 degrees!!

I can thoroughly recommend Vantec 120mm fans, the quoted 20db seems highly probable.

 

[richgtfc]

Ah, those Vantec stealth fans are the exact ones I have....I'm sure they are quieter than normal ones but still a bit nosiy. I think the fan adjuster deal is the thing to get, unless I can get my motherboard (ASUS A7N8X-E) to slow the fans automatically. Is there any software that lets you adjust fan speed. Highly recommend the QTechnology Ultra-Quiet ATX PSU 350W from QuietPC, it's almost completely silent.

 

[KraGorn]

I have the 400w QuietPC PSU, very nice .. AFAIK the ASUS mobo will only control the CPU fan, at least that's what I thought it did when I was installing mine. I'm surprised your Vantecs are noisy, mine are dead quiet ... QuietPC do case fans too, I use one of their 120mms on another PC I have.

 

[mjn]

yeah, that Asus board will only control the CPU fan.

 

[dgc]

richgtfc

Are you sure you can't have a fan at the front of your case?

I've got an Accent (very similar to yours but with no ext 3.5 hole - only 5.5 for the DVD).
The front left has holes drilled(in the case behind the front panel) for mounting a 60mm fan. This allows air to be pulled in from the gap between the front panel and front of the case.
From your pictures it looks like yours may be the same.
I use Fan Mates to control the fan speed and keep noise down.

 

[richgtfc]

Had a look inside the case, there isn't a mounting for a front fan. The right hand side has 2 5 1/2" bays, one has the DVD, the other the card reader in a bay adapter. Below that are the front USB/firewire ports. The LHS has the LEDs and space for a VFD, can't seen any holes for a fan.

 

[Yandros]

Well, I may be a lightweight in the home cinema arena, but I'm on home turf here

Your rear fans are exhaust. Front intakes are a must if you're overclocking, but for a HTPC they're almost certainly unnecessary unless you've got a lot of hot HDDs. I've a pair of Coolermaster chassis. The older is the 100 series with 2x80mm front intake, one rear exhaust and one top exhaust. The newer 220 has 1x80mm rear exhaust, a top 80mm exhaust and that's it! the front is totally sealed in fact - not even a front vent! I've also got low noise fans and acoustic lining. The result is not a lot hotter than the older version, and hell of a lot quieter.

As it happens, I've just finished building a new office PC based on the coolermaster wavemaster chassis. We've been VERY VERY impressed with the noise level. I've replaced the twin 80mm front intakes and 80mm rear exhaust with Papst temperature controlled fans (9-19db) and use a Zalman 7000A AlCu CPU cooler and fanmate. The PSU is a Zalman 400W silent power supply. I've lined the sides with the standard acoustipack matting.

You might want to try the Papst 60mm case fan...

http://www.chillblast.com/customer/home.php?cat=70

Trouble is, 60mm is always going to be noiser than the bigger fans. You might want to try fan mates or dropping the voltage to 5V. Dropping the pitch of the fan noise makes a big difference.

PS

Just noticed the the 60mm Papst from Chillblast comes with an rpm adjusting resistor as well so that looks pretty promising.