Semi-fanless quad core with meshed side door?

NiJo · Post by **NiJo** » Sat Feb 07, 2009 6:09 am

How do you think about this setup for a system that is fanless in idle?

Mid size tower case with a fully meshed side door, e. g. SilverStone SST-KL02B. To help heat convection upwards I'd use it desktop like, so the mesh side is on top.

95 W TDP Intel quad core CPU (Q9300) or 65 W dual core, details not decided yet.

Oversized blow down heat sink, e. g. Cooler Master GeminII (space for 2 120 mm fans).

One slow and silent 120 mm fan on the heat sink blowing upwards through the mesh (or a cut out) under load only, e. g. Noctua NF-S12-800. I could not find out if the 4 pin PWM fan headers on recent motherboards switch off the fan if below a certain temperature. Constant on would be my fallback position. With a 95 W quadcore and 20 cfm ("5 db") I'd get a temperature difference of about 40 Â°C. Cranking up to 35 cfm ("9 dB") I expect a difference of 26 Â°C. With a 65 W dual core I expect 30 Â°C @ 20 cfm or 18Â°C @ 35 cfm .

(Semi-)Passive power supply, eg. NesteQ NA4501 or SilverStone ST45NF. Due to case positioning heat can convect out upwards on a meshed side of the PSU.

Integrated graphics card of G45 chipset. I might add a passively cooled ATI card later.

Silent HDD. With an SSD I'd have no moving parts in idle.

The air flow is from the back and front sides upwards through the large mesh area, supported by the fan if under load. How do you think about this very different concept?

vertigo · Post by **vertigo** » Sat Feb 07, 2009 3:06 pm

-- edit -- I see you will have the fan blowing upwards.

Sounds good, although a bit strange. I'd use 2 very slow fans on that heatsink though. 95W is pretty high (your one fan blowing up could get hot, I think).

NiJo · Post by **NiJo** » Sun Feb 08, 2009 6:59 am

vertigo wrote:your one fan blowing up could get hot, I think.

Good point. Unfortunately I've not seen a heat sink that allows a fan hanging below it and above the CPU. I'd like to keep the second fan slot empty for better air convection. Reversing the air flow (as designed) distributes heat throughout he case.

The more I think about a concept, the more I admire the cooling in my Shuttle box from 6 years ago: Tower heat sinks before it started in standard cases, not polluting the case with hot air, fan controll. Basically I'm trying to imitate that with the new box.

But I had to exchange the very noisy 40 mm Shuttle PSU fan for an externally mounted 60 mm fan also sucking hot air. No problem for a Papst fan. At that time they were considered quiet...