This instructable documents my quest for extremely superior air cooling for my desktop using found materials and the testicle-shrinking chill of a brisk Wisconsin winter. I achieved this by cutting two holes, one in the side of my case, and another in a board which I inserted into my window frame and attached with some wicked plastic ducting. Please read on for details!

Step 1: Hole / Fan Installation in Case

I am basically skipping this step since I did this a long time ago and didn't take any pictures or keep a diary of the event but if you want help there are many guides online already, a good one that I found just by googling is right here. The picture below is the ideal configuration of the hole however this is the top of the case and we want ours on the side for the purposes of this guide. (The second pic is my actual setup)

What you need is a hole in the side of your case, that is going to suck in cool air and blow it onto your preferred components. I chose to make my fan blow directly onto my CPU since I bought a big ol' heat sink with fan already. Specifically I purchased the Thermalright XP-90 shown here and below.

Some tips for this step are:
1. Be EXTRA careful to try and line up the hole you are cutting EXACTLY over your CPU, I used a laser level dohicky for this.
2. Also know your materials and what it takes to cut it, not all cases are made the same, some of the new aluminum models would probably be cut fine with a dremel but I had a tough steel case which I went overboard with and cut with a plasma cutter basically just because I had access to one.
3. Depending on your fan size and case you might have to improvise with the hardware, I thought I could get some screws to mount the fan on the case at a local PC shop but I ended up just going to a hardware store and getting some long screws, rubber washers (reduce vibration noise!), and nuts.

Step 2: Find an Ideal Barrier & Window

This was kind of done for me as my room in my new apartment has one window about 3' wide and the other about 5' wide so it was a no brainer to go with the smaller side window. Then you should find a barrier (ie. a piece of wood) that you can cut a hole in and that will fit inside your window frame semi-snuggly. I happened to find an old, busted computer desk that someone threw out next to my dumpster that I brought inside and left in my kitchen for a month or so, and when I went looking for a barrier for this project actually turned out damn near perfect with almost no modification. I wouldn't expect to be so lucky but just head to the hardware store if you can't find anything suitable.

As you can see this board fits pretty well with a little space on either side, THIS MIGHT BE NECESSARY OR YOU WON'T BE ABLE TO GET IT INTO THE FRAME OF THE WINDOW!

I just measured my hole and traced it (my 120mm fan is actually almost exactly the size of an audio cd) and then drilled a 1/2" hole (wide enough for jigsaw blade) on the perimeter of the larger traced hole and then used a jigsaw to cut out the rest of the hole, you could also just go buy a hole saw bit the size of your fan which might be cheaper depending on the fan size and material. You can see my super modern workshop below (it came with the apartment!) with all the latest trimmings of milk crate sawhorses and an amazing dropcloth waste removal system.

Make sure you cut the hole in the board thinking about where the computer will sit on the sill so there is enough room on either side for the CD drive to come out and to access the cables in the back if you need to.
It might be a good idea to sand the edges of the hole

Step 3: Prepare Your Duct!

This one will probably require some hunting and improvisation. Unless you want to order/buy a professional duct length you will need to find some container that you can make into a tube to direct airflow straight into your computer and not into your toasty room. This website helped my with some inspiration for materials, it has a table with common containers & sizes right here.

I ended up using a section of the tub my favorite fiber supplement comes in although as I mentioned a 120mm fan is about the size of a cd so a cd stack tube would work as well and I actually tried it first but it is a very hard plastic which was too difficult for me to work with.

I had a hard time deciding how to seal the duct onto my case and ended up cutting some cardboard tabs and screwing them onto the case (with the screws already holding the fan) and then just scotch taping them onto the duct plastic. Tape isn't the best but since I used the Caulk Cord to insulate it I think the seal is fine.
This caulk cord is really great and I just realized I could use it not only for this project but for sealing around all the fans inside my case for better control of the air flow. It is removable incase I want to modify this later.

try to get a pretty even cut so there are as few gaps as possible around the edge.
Something I didn't use but I might if it proves a problem later is some foam around the edge that sits against the barrier. This would be great as the computer will be really close to the window and it will be hard to get in there and attach the caulk to seal it against the barrier. (I am not even going to bother until I figure out how much air is really escaping into the room)

Step 4: Final Placement

Stick that sucker on the window sill and let the cool air in!

As you can see I caulked all around the board so hopefully the only cool air will be going into my computer. Be sure to move your hand slowly around the entire window and caulk any place you feel air coming through. Also remember that gap between the halfway open window that you have now, and be sure to stuff somethign in there, my final picture is the lovely, chic placement of some sweatpants in said gap.

This is my first instructable and could have been way better if I had taken more thought about it while doing the project but feel free to offer suggestions and improvements. I am thinking about possibly cutting another hole with some ducting going into the front air intake fan on the case as well as adding another fan to the other side of the wood barrier to really suck that air in.

I am running an AMD64 3200+ (non-OC) and right now my CPU temp is hovering around 29 C with an outdoor temp of 50F, I did this last year in a much worse but essentially the same setup and saw it drop as low as 15 degrees celsius (!) (of course I was freezing my ass off while using it because I didn't have the sweet duct!)

As a final motto: Be careful, have fun, and stuff your caulk in as many gaps as possible!
the only thing i would be worried about would be frost...
If you overclock it enough, you won't have to worry about that! Although, I don't know how long the pc would stay stable for... depends on the parts inside...
I did this last winter and I used just a large computercase fan and a metal bendable gas vent tube and Insulation around the tube, for a filter to keep the dust out I used a filter for a home A/C cut down to size and folded over and taped over the fan. even with my cheap junk CPU heat sink I got temps as low as 19*C . <br /> <br /> Sadly My office in my new house doesn't have a window that opens to outside:(<br /> <br /> It works very well for a ghetto cooling system, Not so well in the summer unless you have a spot that is cool.<br />
&nbsp;Awesome! &nbsp;Did you compensate for the air venting back into the room? &nbsp;I miss seeing those temps...
No I just let it run around in the case then out the back, Come to think of it I should have sealed it off completely and made an exit for the warmed up air to go back outside. This next time I'm going to try and use a Peltier in combination with my new copper Zalman heatsink for sub zero temps...with sub zero temps you must grease up and protect against condensation....lots of stuff on Google about it:)<br />
&nbsp;Wild, I hope you can put an instructable up for that project. &nbsp;I would love to see it come together.
I will have to replace my camera since an instructable is no good with out lots of awesome picture's!<br />
i love this man. wat part of Wisconsin are u from?
any issues with condensation?
I haven't had this set up in over a year, I never lost any components or anything due to condensation, but it must be kept in mind if you are considering a similar set-up.
could set up an air filter to prevent moisture transfer. Though if humidities an issue in your area (whoever is using it), then it will need to be replaced/cleaned often.
I hadn't thought about a filter. Could you use something similar to what filters a dehumidifier ?? Great idea!
Probably something more inline with an oil filter (like for a car or small combustion motor) would be better. But you could try it, worst case, it won't filter too good, but at least it's easier to clean.
Condensation only forms when air is cooled, as the amount of water vapour in air decreases as it cools, this means that no condensation can form on the computer. This is why a dehumidifier in summer makes a room seen cooler and a humidifier is used in winter
true but it fotms humidity and if it builds up to much like our 90% humidity summers, probably not good for the computer! Yikes!
woo, wisconsin = awesome. and, if anyone wants to visit, rember, the weather report means nothing here. our weather is as unpredictable as... well, I won't say anything.<br/>
ive lived in wisconsin all of my life and have never left once all i can say is this state only has a few perks like lots of beer, harley-davidson(all other brands suck), and no helmet laws. other than that wisconsin SUCKS
but on that note madison, milwaukee, and columbus(wisconsin not ohio) are the worst cities in the state
Perhaps you are simply not recognizing many other perks because you haven't traveled to places without them.
Like Minoqua or Hatward!
screw u man!
What about the cheese?
everyone knows Minnesota is better than wisconsin :P
No everyone knows that Wisconsin is better than Minnesota
Melbourne, Australia
Too bad more jobs aren't like weather reporting. hat other job can you be wrong 90% of the time, and not get fired? lol
what happens when it rains or snows.
hehe, my friend did something similar to this, using a cardboard box, an old radiator fan, some dryer hose, and insulation. It works almost too well, his CPU gets down to 5 degrees celcius when he cranks it.
That's hard to believe.
Time for him to overclock to warm it up. ;-P
Why not just use the computer to take some load off the heating system instead of throwing the heat away? Just vent the computer into the room and turn down the heat (if it's central air, install a damper; if it's radiant, turn down the radiator(s)). I realize you will still have to keep the CPU from overheating, but unless you are doing a lot of overclocking, it shouldn't take freezing cold air, and besides, it won't work in the summer. You could even heat your whole house with computers (although electricity is probably more expensive than whatever fossil fuel you are most likely using, and computers are a lot more expensive than furnaces). Just run folding@home constantly and your house will stay toasty warm while helping science!
i've actually seen something like this ran with a air conditioner but like its said be wary of condensation
setup like a water cooler but instead of water connect it too holes in the wall and pump cold air through? if you dont wanna use water or you could try making one, not a big risk with air so it doesnt matter if it doesnt work, unlike a homemade water cooler, where you could drown your pc lol
Another way to do it, without the risk of condensation, would be to have a kind of heat exchange with water, copper pipes and a small pump. Like water cooling, but with a heat exchanger out in the cold.
That would be a hefty project indeed, not sure how to go about it either, maybe you'd like to make your own instructable for it!
"Cool" idea.
masterful pun sir
it would not be a big issue as shortly after powering on the system, it will only allow as much air into the case as is being exhausted.
Hey. totally creative!!!!! lol living in Wisconsin i know the shrinkingly cold weather we get but the thought never occured to me: crap load of subzero air + computer hot enough to fry an egg on.... brillient!<br/>lol u definatly belong in my group: <a href="https://www.instructables.com/group/modthis/">https://www.instructables.com/group/modthis/</a><br/>i'de say hang tight... but evidently the weather has taken care of that...<br/>lol happy modding<br/>
Damprid, i think its calcuim chloride, would work or that silica gel. i would be careful about punk kids walking by and shooting crap in the intake. maybe make a louver or something.
im guessing that this can be pretty effective. although id suggest placing aspen around the hole, to collect moisture. you could also route the cold air through PCV or water-drainy-hose. as for the security, i suggest 2 sealed copper bars filled with antifreeze, it'll do wonders for the cooling (trust me). When experimenting with geothermal cooling i noticed that by leaving 8 of these 4 inch copper capsules in my 5 gallon water tank it lowered temps by 7 celcius!
1. Could you please clarify what this aspen is? You mean those packets that come in pill bottles that are hard to spell? 2. I understand the sealed copper bars but what are you suggesting I do with them exactly? Thanks! (and good suggestion on the PVC!)
oh hey aspen is some fabric. ask for it at home depot. and you make little pills with the copper and fill em with car fluid stuff. they store cold.
If somebody were to want to break in wouldnt this be a ideal location to do such deeds? Don;t you have a death draft comming out of the PSU back? What about moisture? I would think you would get all sorts of moisture in the case now.
I have thought about robbery, I will probably find a bar to stick into the window in its current position, the window is also about 6-7 feet off the ground so that is a slight deterrent (I hope) Your point is definitely valid though, I am going to write down all my serial numbers pretty soon for insurance purposes! Living in a larger city definitely doesn't help my confidence on this issue, it was better last year when I was on the 10th floor. I am attaching two pictures of what it looks like on the outside but basically to get through the window you would have to slice the screen and then try and push the barrier board through whilst not knocking over the computer which would be crazy difficult. Yeah the air coming out of the back is really cold but it definitely gets a tad warmer from the case and I don't mind it for now, if it gets too much later I might have to figure out how to route it somehow. And moisture isn't that much of a problem after about a week or two from now as our winters are crazy dry and I would be more nervous about having it running in my room which will have a humidifier going at night to prevent my lips from breaking off while I sleep.
You're piping cold, dry air into a warmer, moister room. You have (or will have) a condensation issue you need to deal with. This is why you don't see people simply building their computers inside refrigerators.
Ah I see, would venting the air back outside ala the post below this one solve this? Any other suggestions? This didn't seem to negatively effect it last winter, must have just gotten lucky?
If you've gone through an entire winter like this with no ill effects maybe you're safe - maybe there's something about your setup that prevents it. I'd be backing up regularly though. PCs are surprisingly durable, but all it takes is a single short between the wrong pins and your motherboard fries.
Hmm... you know what would be a good idea. Get some of that flexible hose (insulated) used for dryers to vent outside, that way you don't need the computer right next to the window. Not only this, but you'll eliminate another air leak between the case and the duct.
The only reason I like this setup over your suggestion is that I am only using this fan in the computer case so it doesn't get a lot of interference which would be introduced if I used accordion ducting. That stuff would be feasible but I would definitely have to push the air harder through it as I understand it. Feel free to clarify/suggest!

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