Introduction: Cheap Laptop Cooling!

Picture of Cheap Laptop Cooling!

Well, I got a new HP dv9700t for college, but when I play games on it or run any intensive task, it heats up to really high temperatures. I don't want it to break, so I'm trying to cool it. I bought a $40 Rosewill laptop cooling pad, but my GPU still stays around 90C under stress. The Rosewill pad has a nice metal slab to take the heat off, but only two puny USB powered fans that don't put out a whole lot of air.

However, I had a dead dual-fan desktop power supply laying around as well as a fan I tore out of a different power supply (replaced it with a blue fan).

I also had another old PSU lying around that I replaced when I upgraded my graphics card. So, with all of these, I built a very effective laptop cooling fan.

Step 1: Do You Need to Cool?

Picture of Do You Need to Cool?

First, you need to make sure you need a cooling device. If your laptop is only ever used for web browsing and document editing, chances are, cooling units won't help. If you play games a lot, then you'll probably want a cooling device, as gaming stresses the CPU and GPU and causes immense heat output which often can't be handled by the single small fan most laptops have.

Use PC Wizard ( to inspect the temperature of your CPU, motherboard, and GPU as you play games (I hooked up a second monitor, put PC Wizard on it, then fired up games and watched the temperatures change). You can minimize PC Wizard and it will have a small status/temperature notification at the top right of your screen.

Step 2: Take Apart the PSU!

Picture of Take Apart the PSU!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!BE CAREFUL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Computer power supplies (PSU's) have capacitors that can carry a powerful shock, enough to kill you. They hold this charge for a fairly long period of time. If you take apart a PSU, you're safe as long as you don't touch the underside of the circuit board OR any of the capacitors OR any of the metal contacts on the general, just don't touch the metal stuff on the circuit board. I touched the heatsinks, but those are usually just grounded so no big deal. Wear plastic gloves if you so desire. This PSU was a $13 model purchased from Newegg to power a cheap rebuilt PC. It lasted 3 months before I accidentally bumped into the PC and the flimsy heatsinks touched and shorted and fried the PSU (not the computer, thankfully) and took out my whole room in the process (stupid GFI). Newegg RMA'd it and sent me a new one, but due to the cheapness of the PSU, didn't ask for the old one to be returned. Instead of just throwing it out, I figured I'd salvage stuff from it. The first thing to take are the fans.

Take apart the PSU by removing the cover screws. Then you can take the fan off by unscrewing the four fan screws (usually from inside the PSU case). Repeat for the rear fan if your PSU has one.

If you don't have a dead PSU, you can buy cheap case fans online, buy expensive case fans in stores, or ask people who have lots of computers (they might not give them to you though...). You can also find a dead PSU from said people.

Step 3: Tape the Fans Together

Picture of Tape the Fans Together

Simple, lay all 3 fans flat (make sure they're all facing the same direction, the side with the plastic tabs and motor cover (usually a label sticker) is the side air comes out of). Make sure the wires are coming out of the bottom of all 3 fans. Then take electrical tape (or your favorite kind of tape, whatever you want) and tape around all 3 fans until they form one big solid fan brick.

Step 4: Solder the Connections

Picture of Solder the Connections

Solder all the black wires together and all the red wires together. Use electrical tape to cover them and keep them from touching. You only need one connector (I used a 4-pin Molex, which is a good choice if you have an old PSU to run the fans with).

Step 5: Power It Up!

Picture of Power It Up!

If you're using a PSU, you have to jump the green wire to a black wire on the ATX connector. Then plug in your fans, set it next to your laptop, and watch the temps fall.


Just4Fun Media (author)2015-05-26

Great instructable! I built a similar system that is self powered off of the computers waste heat! And I was able to reach core tempatures of 4.2 degrees Celsius!

alaskansnowboarder (author)2014-01-16

Buy a harddrive power supply the dual voltage 12v and 5v @ 2amps .. I purchased these in bulk and have many uses, because they have the dual voltage. I use them in my greenhouse to power 120mm PC fans. I use pvc pipe to make a mount for my fans..

OzzyManson (author)2013-06-19

what MM of fan would you suggest for this? my laptop is currently sitting at 51*C and im not even playing games or really doing anything.

vanwazltoff (author)2012-11-06

if your computer is running at ridiculous temps you probably need to replace the thermal compound with something like timtronics grey ice 4200. thermal paste should be replaced at least every 2 years, this explains why it gets hotter and hotter over time. a good quality thermal paste can significantly decrease processor/graphics temperatures. companies such as HP do things on the cheap and dont use a quality thermal paste and often run way too hot out of the factory

The laptop died a year later of heat-related GPU failure, once it came back with a new board I eventually tore it apart and re-applied paste (Arctic Silver 5, not the best but it's what I had) which did lower temps. Recently got a new laptop that doesn't run so hot, it's an HP but it's AMD based.

MRedu (author)2011-10-17

Great guide +1 especially if you have a cheap laptop that is overheating. One thing i was wondering, does it matter if the fans are blowing air away from the laptop or into the laptop? Or does it matter?

tomkat1982 (author)2010-10-12

Very helpful. Great stuff, thanks.

rkr (author)2010-02-25

90 degrees should technically be burning up. And if anyone's interested (as I was reading some other comments), here is a great site for pin-outs:

kenshinruff (author)2009-05-17

When I jump the green wire to the black wire there is a noticeable ring emanating from the psu that is not there when I have it connected to a motherboard. Anybody know how to fix this?

This could be from a weak capacitor or a worn out fan. Switching PSU's (what ATX PSU's are) use high-frequency AC electricity which can sometimes create a high-frequency audible sound, usually from the transformer. I guess it has to do with how much power you're drawing. If you're only running fans, chances are the 5V (red wires) rail is not connected to anything.

shadowsniper918 (author)2009-03-21

the green wire is that the "sense wire" to trigger psu to turn on ?

Yeah, ATX power supplies have an always-on +5V Standby (the purple wire) that is always on. To turn the rest of the power supply on, you have to short the green (PS-ON) wire to ground. It's basically the power switch for the PSU.

mikemmcmeans (author)2009-03-05

when i'm running world of warcraft and windows media player the temp tops out at about 60C on each core

UberPug (author)2008-06-23

whoa.. 90 degrees is serious. is that even safe?

CalcProgrammer1 (author)UberPug2008-06-23

Probably not, that's why I really needed to cool it off. The computer only has an 8600M GS but must have a very poor heatsink. Laptop stuff is designed for higher heat tolerance than desktop though, because laptops obviously have poor cooling (usually one 40mm fan or so for a dual core CPU and a graphics card) while desktops have better cooling.

Derin (author)CalcProgrammer12008-07-01

my desktop runs at 60deg with a clogged fan

CalcProgrammer1 (author)Derin2008-07-01

Desktop parts always run much cooler than their laptop counterparts. An average desktop CPU should run around 40-50 degrees, maybe peaking near 55 to 60 under intense loads, while laptop CPU's idle around 50-60 on normal cooling (the built in heatsink/fan) and approach 70 under intense loads. This is because the CPU on a desktop has a big block of metal sitting right on top of it as well as a large fan on top of that. Desktops also have case fans, room for air to move around, separate GPU fans, and sometimes intake fans. Laptops usually share one heatsink for the GPU and CPU, usually with just one tiny 40mm or so fan that gets limited airflow due to the small opening and lack of empty space in the case. With real desktop fans cooling a laptop, you can get much lower temps (my CPU idles around 30 with the 3 desktop fans blowing on my laptop).

Wait what? How would a mere fan get anything below room temperature? Once your CPU drops below 70 or whatever it is in the room, even infinitely increased airflow should warm the CPU up, not cool it off.

smurfsahoy (author)smurfsahoy2009-02-01

Oh celsius, nevermind hah

Derin (author)CalcProgrammer12008-07-01

correct.I did the solution that my uncle did:remove the cover it helped cooling,it floats around at 58deg idle because of the vista bloat but the fan is not a jet plane anymore ps the clogged fan is one of the AUX fans which arent crucial

Derin (author)2008-07-16

80C?now THAT is extreme!So hot u can boil water with it!

CalcProgrammer1 (author)Derin2008-07-17

Boiling point of water = 100C
Freezing point of water = 0C

Boiling point of water = 212F
Freezing point of water = 32F

This is at standard pressure (1 atm). I suppose that on the top of some really tall mountain or on an airplane without a pressurized cabin, you could probably boil water at 80C, but then again you can boil water at room temperature if you lower the pressure enough.

80C is high, but then again it's a powerful GPU in a laptop. It was over 90, but with cooling that problem is solved. I too question how safe that heat is, but apparently it must be fine or else they would have designed it with more fans.

Derin (author)CalcProgrammer12009-01-25

Mine runs pretty hot,but I never maintained the temps.It is an old IBM thinkpad.I will try checking temps through BIOS.

dracus (author)CalcProgrammer12008-07-27

mine has reached 95c. then it shut off lol good thing i have it protected to shut or...

Shagglepuff (author)Derin2008-07-22

My laptop gets hotter than that computer.

How hot does yours get (CPU and GPU temperatures)? 90 degrees is some serious heat, so you might want to look into getting something to cool it down with.

After a while, the bottom gets too hot to touch. I bet that if you tried to touch the heatsink, you would get some serious burns. Sometimes, I keep an icepak under my computer;it temporarily cools it down.

dracus (author)2008-07-27

i was goin for the same thing, i got the same notebook too. it sure does get hot. expesialy when gaming lol. i wired the fans into a wall adapter. works ok, but its ony 5v.... I was just trying to see if it would work... now im looking for a 12v... lol

CalcProgrammer1 (author)dracus2008-07-27

Yeah, I was using a 9v wall adapter as well (the PSU was too big to manage) and it works great on a 12v wall adapter as well (but I'm using both of those adapters in other stuff now).

dracus (author)CalcProgrammer12008-07-27

but seriously hp should have done something about the amout of heat it gernerates... Im in the proccess of building a stand that will prop it up as high as it can go and im going to put fans under the HDD's and the RAM because well... thats where it gats hot lol. So im basically going to make a docking station and im going to mout the hp quickdock to it. it'l be great.

dracus (author)dracus2008-07-27

I also thought of mounting the fans in the desk itself but my plan was to make the dock. But it would be a good idea if the computer is always in the same spot and you dont need to move it to have enough room on the desk for other stuff. and if you want the computer to sit flat.

CalcProgrammer1 (author)dracus2008-07-27

I have a cooling pad, but the problem with it is it doesn't elevate the back of the laptop enough. The dv9000's intake vent is designed to have more clearance below it than it gets sitting on a surface. I know, stupid design. Fans mounted right under the intake vent (where the PC's fan is) would help, as long as they blow in the same direction (blowing up towards the PC, not away). It sounds like a good idea though, so if you can, take pics when it's done.

Yerboogieman (author)2008-07-24

Hey man! Just Cool it!

Sinner3k (author)2008-07-01

Just a thought, could you maybe show what your laptop runs at now using PC Wizard so we can see the actual improvement?

CalcProgrammer1 (author)Sinner3k2008-07-01

The picture posted of PC Wizard is with the fan running. While that's open, I'm running the Folding@Home GPU2 Beta client (why my GPU is hot) as well as the Folding@Home SMP client (why my CPU is hot). Those programs use the CPU/GPU at a full 100%, so they are pretty much the same as stress testing. I could take a screenshot of my laptop running these programs without the fan (or the cooling pad, which lowers temperatures but not as much as the fan does).

Sinner3k (author)CalcProgrammer12008-07-02

Got it, thanks for clearing that up. I need to build my laptop cooler so I can run SETI@home constantly.

About This Instructable



Bio: I finally graduated from Missouri University of Science and Technology (Missouri S&T, formerly University of Missouri Rolla) with a computer engineering degree. Originally from ... More »
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