When I was little, I remembered my dad telling me that when he was a kid, they used to put buckets of ice in front of a fan and it worked wonders. Well, today while working on my Altoids USB charger (had to wait for my epoxy to dry), it got very hot in the room and I needed to find a place to cool down. Unfortunately my whole-house air conditioner is broken and my landlord is too cheap to fix it. So, I decided to use some common household supplies to make my own, only USB powered.
Supplies:
-Old USB cord. Any kind will due, from any device. Preferably one that you no longer use.
-Container of some sort.
-Knife / scissors / wire cutters.
-Glue gun.
-Soldering iron. This isn't essential, but recommended.
-Old PC fan. Clean the dust out first.
-Electrical tape.
-Ice.
Let's get started.
[b]Step 1 - Cut holes in your enclosure.[/b]
[img]http://img189.imageshack.us/img189/1796/step1zu.jpg[/img]
You can use any kind of enclosure you want. RadioShack sells large ones for about $8, however they're strong ABS plastic and are not exactly meant to be opened and closed. I used a Domino Sugar container, which has a soft plastic which is easy to cut.
Start to cut holes around your enclosure, but not TOO large. You want multiple small holes. Trace and cut out an area for your fan. Do NOT trace it too small, leave some area for your fan to sit comfortably on top.
[b]Step 2 - Mount and glue your fan.[/b]
[img]http://img833.imageshack.us/img833/8564/step2wv.jpg[/img]
You'll want to use a hot glue gun. Superglue and epoxy will work, but it takes forever to dry and does not offer the beast sealant. Put glue around the perimeter. Make sure you leave no areas unsealed. Make sure you test your fan ahead of time to see what side air blows out of. Normally it's label side. Nearly all fans are 12v, but USB only really hits about 5v. The fan will spin somewhat slower, but you will still feel the cold air.
[b]Step 3 - Strip your USB cord.[/b]
[img]http://img812.imageshack.us/img812/576/step3r.jpg[/img]
Find an old USB cord. Cut the top off using wire cutters or snips. Proceed to strip the plastic around the edge off the remaining part, exposing the wires. Do NOT clamp too hard, otherwise you'll cut through the wires.
[img]http://img69.imageshack.us/img69/9532/step4c.jpg[/img]
The green / white wires are not needed, as they are the wires that actually carry data. We only want the positive (black) and negative (red) wires. Cut the green and white wires short.
[b]Step 4 - Twine your wires together.[/b]
[img]http://img809.imageshack.us/img809/1707/step5n.jpg[/img]
The reason we do this is to make a secure connection so we can solder it and form our joint. Negative (red) goes with negative (red), and positive (black) goes with positive (black).
[b]Step 5 - Solder OR tape your wires together.[/b]
[img]http://img440.imageshack.us/img440/3058/step6m.jpg[/img]
I suggest soldering, but if you do not own a soldering iron or you do not know how to solder efficiently, you can skip to the step below and tape without soldering.
[b]Step 6 - Wrap each joint.[/img]
[img]http://img585.imageshack.us/img585/3302/step7y.jpg[/img]
Do this even if you are not planning to solder. Wrapping the joints is essential to prevent short-circuiting.
[b]Step 7 - Wrap both joints together.[/b]
[img]http://img545.imageshack.us/img545/3499/step8e.jpg[/img]
Make sure you wrap them nice and tight, as you don't want the wires slipping out (if you didn't solder them).
[b]Step 8 - Obtain some ice and place it in your container.[/b]
[img]http://img407.imageshack.us/img407/135/step9k.jpg[/img]
[img]http://img705.imageshack.us/img705/8998/step10t.jpg[/img]
I made some cheap ice packs (though you can get ice packs cheap for about $1 a piece) using sandwich bags, water, and tape. I don't suggest using loose ice, as it is a pain to clean up and if you spill it, it can ruin your fan.
[b]Step 9 - Secure your lid.[/b]
[img]http://img20.imageshack.us/img20/6628/step11d.jpg[/img]
This part is essential. If you do not properly fasten your lid, you won't notice any cold air.
[b]Step 10 - Plug it in, and enjoy.[/b]
[img]http://img338.imageshack.us/img338/8303/step12t.jpg[/img]
If you did it right, your fan should start working when you plug in your USB cable. It works for wall chargers as well. It's been sitting at my video editing PC for the last hour, and is noticeably cold.
A few things. You will NOT notice a difference across the room. This is mainly for a small area. Also, the ice will melt in about two hours, depending on amount of ice. Keep extra packs on hand for hot days. It's 78 in here, after plugging it in, it dropped it down to about 68 degrees in my area.
If you REALLY wanted to get technical, you could add a toggle switch to turn it on / off. All you would need to do is solder it in between the negatives (red).
Enjoy?
I'll let all my ghetto friends know.
You could just buy a cheap fan instead, I got one and it works wonders.
But this probably works well if you're poor v:v:v
I made one with a 22 liter plastic tub and two 120mm fans the other day and these simply don't work. You need to put a hell of a lot more engineering into it to get anything remotely effective.
Just save up for a little while and get a real AC. It's an absolutely amazing investment for the summer.
[QUOTE=chipset;36076538]I made one with a 22 liter plastic tub and two 120mm fans the other day and these simply don't work. You need to put a hell of a lot more engineering into it to get anything remotely effective.
Just save up for a little while and get a real AC. It's an absolutely amazing investment for the summer.[/QUOTE]
You did something wrong then, because it DOES work. It most likely didn't work because of the large size of your container, and only using two 120mm fans. The larger your container the more fans you need to use, two for a 22 liter simply does not cut it.
Great Tutorial, I did one of these my self once. A slightly different design though, I used a cardboard box and 3 Case fans powered by 12V Mains.
[QUOTE=CrispexOps;36072068]A few things. You will NOT notice a difference across the room.[/QUOTE]
I disagree.
I once got a large fan (15") and put it in front of a large tray of ice (The kind of trays you put in a large draw to organise all of your knifes and forks.) - It did a great job of cooling the room.
Having said that, the ice didn't last very long and it took too long to re-freeze enough ice to make it a continuous thing. It also makes the room more humid.
A better choice is to just get air conditioning. :)
[b]Chipset:[/b] There is more science in this than just cooling down an object and putting a fan in-front of it. Ice works because it requires a phase-change (Solid -> Liquid) to heat up above 0C. Phase-change is used in real air conditioning units, only in those it is a continuous process.
As you heat up ice it stops at 0C. From there it will not get any hotter until the ice has actually melted, which requires a certain amount of energy. ([url=http://en.wikipedia.org/wiki/Latent_heat]Latent heat energy[/url]) Only after the phase-change has completed can it heat up above 0C. It is this phase-changing state which is actually providing most of the cooling effect.
I think it's [i]pretty cool[/i] how phase-change works.
[quote]I once got a large fan (15") and put it in front of a large tray of ice (The kind of trays you put in a large draw to organise all of your knifes and forks.) - It did a great job of cooling the room.[/quote]
I was talking about the size of the unit I made, not a larger vat of ice and a larger fan.
[QUOTE=AeroSinthetic;36074115]I'll let all my ghetto friends know.[/QUOTE]
The only interesting after school club. Ghetto DIY.
I've found placing a large coulender full of ice in a metal bowl that has been lightly salted directly behind a tower fan can cool a room by a perceptible amount in the time it takes the ice to melt.
[editline]19th July 2012[/editline]
What I intend to build -
[IMG]http://i.cubeupload.com/qUhavk.jpg[/IMG]
*ice will go in the bottom, too which will be lightly salted, while the ice in the middle will melt from airflow.
I tried this and it works pretty well but I have a suggestion.
120mm fans are, generally, 12v. A USB outlet only puts out 5v. I noticed when I made mine that the fan spun relatively slowly, and didn't move a lot of air.
I fixed this by getting an 8AA battery holder (AA batteries are 1.5v each and when run in tandem like with the battery holder, outputs 12v)
RadioShack has some nice 8AA battery holders with clip terminals on them (like 9v batteries have). Get one of those and a 9v battery clip and wire the fan directly to that, it works MUCH better.
Yes, it does use AA batteries but I find that a set of 8 batteries will last anywhere from 24-48 hours before needing replacement. So you can get several days of 8 hour use out of them.
If I started a fire in the tub would it have a heating effect?
[QUOTE=Flyingman356;36869936]If I started a fire in the tub would it have a heating effect?[/QUOTE]
With the added benefit of a carbon monoxide effect.
aren't these things dangerous as shit? (judging by the speed of the fan)
Has anyone tried it with dry ice ?
If you have extra USB cables and spare ports, could you make two (or three) "power adapters" and connect them in series to get 10-15 volts and thus more airflow?
[b]Edit:[/b]
After thinking about it, I guess you'd just be shorting out your 5v circuits. I guess you'd have to use multiple cables in parallel and a DC to DC converter to turn the extra current into extra volts.
You could possibly isolate each of them with transformers and then connect them up but thats way more expensive than the scope of this project. If you have the necessary crimping tools to hand and a power supply in your computer that has molex connector you could make up a connector to draw off +12v and gnd (yellow and black iirc) which the fans are designed to run off in the first place.
May i also note, that the Black, is the ground or Negative, while Red is the Positive.
Red = Danger, which is where the current is.
[QUOTE=Chryseus;36897368]Has anyone tried it with dry ice ?[/QUOTE]
No but Liquid Oxygen worked fine.
[QUOTE=andreblue;36940811]May i also note, that the Black, is the ground or Negative, while Red is the Positive.
Red = Danger, which is where the current is.[/QUOTE]
Black is not negative. Unless you take red/yellow to be your reference voltage (or 0v) which would be incredibly silly. Current can flow in any wire regardless of colour, black just happens to be effectively at the same potential as you (it's grounded) so is harmless (assuming you too are grounded).
A final point, the current and voltage involved in USB/Molex connectors are entirely harmless.
I'm assuming you realise in mains that there are no red wires.
I'm assuming the soldering goes like this
Fan -> USB
Blue -> Blue
Green -> Green
Yellow -> Yellow
Black -> Red
[editline]27th July 2012[/editline]
because this discussion is confusing me
[QUOTE=andreblue;36940811]May i also note, that the Black, is the ground or Negative, while Red is the Positive.
Red = Danger, which is where the current is.[/QUOTE]
Good luck getting shocked by an USB port.
[editline]27th July 2012[/editline]
[QUOTE=Justin Case;36951666]I'm assuming the soldering goes like this
Fan -> USB
Blue -> Blue
Green -> Green
Yellow -> Yellow
Black -> Red
[editline]27th July 2012[/editline]
because this discussion is confusing me[/QUOTE]
If you are using USB to power the fan and it has a 4 pin connector you just have to wire up the red/black to the red/black of the USB connector.
Just finished soldering and taping the wires together, did exactly as instructed but the fan doesn't spin...
[QUOTE=Justin Case;36959957]Just finished soldering and taping the wires together, did exactly as instructed but the fan doesn't spin...[/QUOTE]
Did you wire up [b]only[/b] the red and black wire of the USB connector, so red -> red and black -> black.
You'd probably have an easier time using the 5V or 12V from a molex connector, a lot more current is available so you can drive bigger fans and it does not take up a usb socket.
[QUOTE=Chryseus;36962729]Did you wire up [b]only[/b] the red and black wire of the USB connector, so red -> red and black -> black.
You'd probably have an easier time using the 5V or 12V from a molex connector, a lot more current is available so you can drive bigger fans and it does not take up a usb socket.[/QUOTE]
Oh I did all of them, the pictures look like all the greens and yellows etc were are all soldered too
[editline]27th July 2012[/editline]
Also just realised that the fan instructed has 2 wires, mine has 4, a Green Black Blue and Yellow
[QUOTE=metallics;36945734]Black is not negative. Unless you take red/yellow to be your reference voltage (or 0v) which would be incredibly silly. Current can flow in any wire regardless of colour, black just happens to be effectively at the same potential as you (it's grounded) so is harmless (assuming you too are grounded).
A final point, the current and voltage involved in USB/Molex connectors are entirely harmless.
I'm assuming you realise in mains that there are no red wires.[/QUOTE]
White, which is considered the Hot line. But AC is not DC, with usb it is DC
[QUOTE=ddrl46;36957703]Good luck getting shocked by an USB port.
[editline]27th July 2012[/editline]
If you are using USB to power the fan and it has a 4 pin connector you just have to wire up the red/black to the red/black of the USB connector.[/QUOTE]
I meant the Red = danger as in the fact, it will most likely always have the amps running thru it.
[QUOTE=randomGuest;36894736]aren't these things dangerous as shit? (judging by the speed of the fan)[/QUOTE]
They're plastic fan blades. You can stick your finger into one and it just stings a little and immediately stops.
If a ceiling fan on high can't cut off your head, a CPU fan can't cut off your finger.
[editline]28th July 2012[/editline]
[QUOTE=mblunk;36939255]If you have extra USB cables and spare ports, could you make two (or three) "power adapters" and connect them in series to get 10-15 volts and thus more airflow?
[b]Edit:[/b]
After thinking about it, I guess you'd just be shorting out your 5v circuits. I guess you'd have to use multiple cables in parallel and a DC to DC converter to turn the extra current into extra volts.[/QUOTE]
[QUOTE=metallics;36940206]You could possibly isolate each of them with transformers and then connect them up but thats way more expensive than the scope of this project. If you have the necessary crimping tools to hand and a power supply in your computer that has molex connector you could make up a connector to draw off +12v and gnd (yellow and black iirc) which the fans are designed to run off in the first place.[/QUOTE]
Or you could do what I posted for about an extra $3 and use an 8AA battery holder which gives it the perfect 12v
[QUOTE=Yersinia;36971189]They're plastic fan blades. You can stick your finger into one and it just stings a little and immediately stops.
If a ceiling fan on high can't cut off your head, a CPU fan can't cut off your finger.
[editline]28th July 2012[/editline]
Or you could do what I posted for about an extra $3 and use an 8AA battery holder which gives it the perfect 12v[/QUOTE]
8 AA batteries are expensive. Also without regulation you're much more likely to get "perfect 12v" (closer to it anyway) from your computer PSU. molex connectors are cheaper than $3, I don't see how your suggestion is in any way better, especially when an (uneccessarily for this application) well regulated supply is going to be close at hand the whle time.
[editline]28th July 2012[/editline]
[QUOTE=andreblue;36967038]White, which is considered the Hot line. But AC is not DC, with usb it is DC
I meant the Red = danger as in the fact, it will most likely always have the amps running thru it.[/QUOTE]
You're a bit of a muppet, I'm not sure where to start.
Porbably back to my earlier point of current can run in any wire regardless of colour. You're making a big assumption that red is going to be "dangerous", if I came upon an entirely unknown system I'd consider everything live until I knew otherwise.
Also, if you have 2 wires connected to a fan, one red and one black, assuming the system can be roughly modelled as a single resistance, which you can the capacitance and inductance are going to be negligible) then whatever current flows in the red wire will flow in the black wire and vice versa. I think what you were possibly getting at is that the red wire may have the greater potential difference between it and yourself, but even so, back to ddrl46s point, good luck getting shocked off a USB line, and assuming you did, you're a muppet for working on it whilst it is powered.
I think this design would work better for you OP
[img]https://dl.dropbox.com/u/5831868/aircon.png[/img]
It's like an automatic bong, just without the weed.
[QUOTE=Yersinia;36971189]They're plastic fan blades. You can stick your finger into one and it just stings a little and immediately stops.
If a ceiling fan on high can't cut off your head, a CPU fan can't cut off your finger.[/QUOTE]
Have you ever seen someone's finger after they touched a car's fan ? (It had plastic blades)
It didn't remove the finger, but it made a mess.
[QUOTE='[EG] Pepper;36980511']I think this design would work better for you OP
[img]https://dl.dropbox.com/u/5831868/aircon.png[/img]
It's like an automatic bong, just without the weed.[/QUOTE]
Here's a better bong cooler design:
[img]http://img74.imageshack.us/img74/9343/bongeb2.jpg[/img]
That setup was for water-cooling a PC, but you can just connect the pump outlet straight to the shower head. By using a shower head (Or even better a mist jet) you increase the surface area of the water. With this you can get the water to evaporate easier and this will cool the room down. It will of-course make the room very humid.
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