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Cool Down Your PC

Revised on

25 degrees too hot

There are more websites dedicated to cooling PCs than there are websites to cure hiccups.

I had just performed an upgrade for a client who had a old Intel based motherboard (550mhz I think) and he wanted something a bit faster and cheap. I suggested a A7N266-VM motherboard by Asus and a Athlon 2000+ CPU with 256mb of PC2100 DDR memory. I'll use his old 20gb hard drive, CDRW and case.

After I built the system I noticed it was running fairly hot. Just placing my hand on the top of the case I could feel a great deal of heat building up in the top of the case. The culprit was the heatsink on the chipset. Man alive it gets really hot.

This wasn't good. I went into the BIOs and under Power the Hardware Monitor said it was running at 122 degrees. AMD says you can run these CPUs at well above 140, but this is just a little too hot me.

His old case was poorly designed with no vents or even a place for heat to escape through the top. I thought I would drill a hole in the top directly over the CPU and chipset heatsink and mount a temperature sensitive 80mm fan up there.

My first inclination was to let the fan pull air out of the top therefore relieving all the heat buildup in the top of the case. I drilled my hole (see my hole drilling PC Project) and mounted my Enermax Ultra-Cool Thermo Control Second Fan Kit right in the top.

I let it run for a while (about an hour) and looked at the BIOs again to see what the temp was... only 114! It only cooled it down 10 degrees! Fark! I opened the case and moved some wires around to make the path for air to flow better from the bottom to the top. I let it run again for about 30 minutes and still the same temp. 114.

I got out my head scratcher and looked at my design. I'm no rocket scientist, but man this should work better than 10 degrees. I thought maybe my cheap fan idea wasn't going to work and I will have to blow $50 or more on one of those new fangled super-coolers.

Okay, so I had a fan in the top of the case and I also had one in the front of the case. The fan in power supply should be helping out too right? Well it does pull air away from the CPU but I think the fan in the power supply was designed for the power supply. If it helped out the CPU at all consider that a bonus.

Hey! I thought... I have one of these Antec 330watt duel fan power supplies. You know... the one with the extra large fan that hangs right over the CPU and heatsink. That's the ticket! Okay. Now I pulled out all the power lines going to the hard drive, floppy and such and plugged it in and tucked all the wires so that my chipset could get maximum airflow...

Guess what...

Nada. After letting it run for an hour and a half, I only got it to cool down to 113.5. That big ass fan right there hanging over the CPU and heatsink isn't doing it. What a rip. I do like Antec, but these duel fan setups are for looks, not for cooling.

So I put the other, cheaper 300watt in there and then it hit me...I'll reverse the fan in the top of the case to pull air in and down to the bottom of the case. It'll pull air in from the top, down over the CPU and chipset heatsink, then the front mounted case fan will pull it out the front! Currently, the front mounted case fan (like most computer cases) pulls air in from the front of the computer and across the expansion cards. I'll reverse it and see what happens...

Well after letting it run all night running Passmarks Burn In Test Standard, I am very happy to announce that the CPU and motherboard temps were 93 and 89 degrees!

Yup. Not bad I'd say thank you very much. No need to buy a $50 super-cooler and any anti-freeze here kids. Just good 'ol fashioned reverse airflow engineering!

Keep in mind that this article deals with a computer case that is mostly standard in the industry and your case might need a different solution. The point I'm trying to make is that your should experiment and play with your own particular design to achieve maximum results.

So hold you nose high and spend that $50 on a good dinner with your honey and I guarantee you that you'll need more than this solution to cool that down...





The case after surgury

Thermo-Fan ($5 bucks)

"The Culprit"

Antec 330w Dual-fan PS

Front case fan reversed

Working solution...


Thermo-Fan from