CPU Cooling Fan

[Chris Hogg]

The cooling fan on the CPU of my Packard Bell PC is getting noisy, especially when it's working hard to cool the CPU at times of peak activity. I've opened up the computer case and cleaned the fluff off the fins on the heat sink and fan blades, and replaced the heat sink compound, but it's still a bit noisy. The computer is several years old now (running Win XP), and over the last 18 months it's been on

24/7, so I expect the fan is showing its age.

I've looked on the Internet for a replacement, but can't find the exact model, although similar models are available from China. I'm reluctant to commit to buying one from there. The fan is an AVC DS08025R12UP, and I believe the specs are 4600 rpm max, 64 cfm/min, 4 pin connector, 80x80x25 mm, 12 v 0.7 a, and clips onto the plastic holder for the cooling fins.

Are there generic replacements for such a fan. If so, could someone point me in the direction of a supplier and model no.? What key properties should I be looking for? It obviously has to fit the clips on the heat sink, as well as having enough capacity to deal with CPU power surges, but what about the power supply and connections to the motherboard? Or is replacement just straightforward and I'm worrying too much?

Failing that, I read the fan has 'fluid bearings'. Is it possible to oil such a fan, using light machine oil for example (my wife has a little bottle of same for her sewing machine). If so, where do I apply it. There are adhesive labels on both top and bottom of the fan, which may cover an oil-hole. Is this likely?

One more question: when I took the fan out, I forgot to note which way up it sat on the heat-sink, i.e. whether the air was blown down through the fins or drawn up through them. Which should it be, or doesn't it matter?

[Harry Bloomfield]

Chris Hogg expressed precisely :

I found lots of sources for exact replacements, just type 'AVC DS08025R12UP' into google.

Here is one.....

[Dave Baker]

Indeed. A drop or two of light oil inside the bearing generally sorts them out quite nicely IME.

[Chris Hogg]

Err...yes. Thanks. Seen that. Condition: used. Already got one of them. One or two more like that. Microdream in the UK are out of stock. Buysources is in China, as is Aliexpress (condition: used, again). Codemicro do them 'refurbished', whatever that means, Buyqual is in Taiwan, and so on. Partzdepot is a possibility, although I'm not sure where they are, possibly US, but I was hoping for something closer to home, or a UK sourced generic replacement.

[Mentalguy2k8]

If you can rest the old one back on the heatsink it should be obvious which way up it goes. Sticker on the top, little arrows to show which way it turns, indentations where the clips hold it, etc.

Generally fans attached to the heatsink in a simple setup, blow *towards* the heatsink.

While you're there, you might as well give the case fan a good clean too.

[Mentalguy2k8]

Is America any better?

I think it works out about 12 quid.

[Chris Hogg]

Thanks. Just come across these on YouTube:

and a follow-up Exactly what I want and simple enough; same fan too; I'll give it a try.

[Dave Liquorice]

Should be possible, PC parts are pretty standardsised. Just find a 64 cfm or there about fan of the right physical size with a 4 pin connection (though that isn't abbsolutely essential).

[DaveyWavey]

I've built quite a few of my own PCs in the past, and in my experience all CPU fans of a certain size (e.g. 80mm) have standard dimensions, and are pretty-much interchangable from an ergonomic perspective.

I suppose it's possible that Packard Bell have used a special, bespoke, proprietary fan with different dimensions, but it strikes me as unlikely (especially for any PC manufactured within the last 10-15 years).

You might want to check the spec of the connector, as these can vary between fans, although they are still usually standard (and many fans ship with converters between the common connector types).

When I started building PCs, the common advice was to 'suck' air away from the heatsink. This advice has changed since, though, and now the conventional wisdom appears to be to blow air into the heatsink.

[Chris Hogg]

'Used' again. Thanks anyway.

[Chris Hogg]

Good, and thanks. Should make finding a replacement easier, if it comes to it.

[Chris Hogg]

Thanks Davey. Encouraging to know. I _think_ I've got mine the right way up, and I _think_ it sucks the air up through the heat sink, but from what you say, it probably doesn't matter too much as long as there's plenty of air movement there.

[Harry Bloomfield]

I think it will need to be four pin, if the speed needs to be controlled - otherwise it will run flat out constantly.

[DaveyWavey]

You can actually test the efficiency of each configuration, if you like. You can install some software to monitor your CPU core temperatures -- the more effective the cooling, the lower CPU the temperature (compared to the case temperature).

I personally use Core Temp

for day-to-day monitoring, but there are dozens of alternatives.

To really test the fan's CPU cooling performance, you need to test it under heavy CPU load. Prime95 is one of the most effective tools for this

. Use with caution.

[Nick]

You could try posting this on uk.comp.homebuilt. There are some V knowledgeable and helpful folk there. There was a lady called Dorothy Bradbury who was acknowledged as an expert on fans. She also sold Panaflo fans which were regarded as top of the market. Don't know if she's still around. hth Nick.

[The Natural Philosopher]

It matters very much. Blowing as against sucking makes 2-3 times the difference.

[Chris Hogg]

Thanks TNP. I'll make sure it blows when I re-assemble it after oiling the bearing. There are arrows on the side showing direction of rotation and air-flow.

[Brian Gaff]

Most of mine blow down and out the side by the looks, erm feel, of it!

Brian

[Grimly Curmudgeon]

Certainly is.

I haven't bought any fans recently, but she'll be first port of call.

[PeterC]

Having the fan blowing towards the CPU is also often used to cool the voltage regulators and RAM as well.