I recently had a chance to go over a friend's house to help her hook up the computer I had sold to her earlier last year. Since I just recently caught the modding bug, I thought that I would pop off the side panel to take a look at what I used to have. I found something extremely strange and I was wondering if this was an outdated idea, an idea that didn't hit the mainstream, or just a really bad idea that thankfully grew out of habit.

The old computer had a PIII 866MHz with a heatsink but no fan. However, this series of computers from the maker used an incredibily tiny PSU (proprietary, and only 160W) that was seated sideways next to the mobo and they had plastic duct work surrounding the heatsink all the way to the PSU's intake fan.

So, no fan on the heatsink, but the intake fan on the PSU was pulling the hot air off the heatsink via the ductwork and shooting it out the back of the pc tower.

Does this seem like an effective way to keep your cpu hs cool? Since the fan isn't sitting directly on the heatsink, you wouldn't have the dead spot. On the downside, it would seem like you would overheat your PSU and it would cover up part of your bragging rights on the mobo (namely, the type of heatsink).

Anybody have any thoughts on this?

Rob

I don't think the 866 is getting too hot, so I think it's okay. My P3 800@1000Mhz doesn't get too hot, runs around 75F, and I can run it passive at 85F. These CPU's just don't heat that much. As for the ducting system, I think it's a good idea for the OEM crowd. Cuts down on noise and I guess it does decent cooling.

sound like what im doing with my 233mhz its called passive cooling and its ver effective for the most part

The concept isn't any different than an Alpha sink. However, I wouldn't try that with any CPU made in this millenium unless the heatsink tines reached to the PSU and the fan sucked 50+ CFM. Then again, why put a fan in a PSU if all you are going do is heat it up some more?

I go by the theory of if it works then why fix it. If there isn't any problems then I would worry about it.

ive seen this in one or 2 old HP netservers - they used an exhaust fan tho rather than the psu to pull the heat out. AT 180W that PC isnt going very far tho - there probably already a lot of strain on the PSU to pull of the power consumption, let alon have the heat soming off the CPU going through it.

Personally I wouldnt recomend it with any newer system - 1Ghz and under should be fine.

Quote: Originally Posted by nev_payne ive seen this in one or 2 old HP netservers - they used an exhaust fan tho rather than the psu to pull the heat out. AT 180W that PC isnt going very far tho - there probably already a lot of strain on the PSU to pull of the power consumption, let alon have the heat soming off the CPU going through it. Personally I wouldnt recomend it with any newer system - 1Ghz and under should be fine.

Actually the system is still very much in use, sometimes using redundant exhaust fans (each fan has two separate motors in the hub) for a number of ultra high density xeon blade servers. My team at work is currently designing the ducting to apply the same system to a proprietary Opteron 250 server solution. It still depends just on how much air your fan moves and how thermally tolerant your components are.