Hackaday Lazy Afternoons

Lazy Afternoons

whew! way to beat the heat by reading us on a lazy afternoon like this! I hope everyone shows up to our hackaday meetup tomorrow dressed properly and with water (no goth clothing. too hot)!

Yes, meetings will be filmed (our philly one at least) and we’ll later be providing the video for all who missed out to download and watch. see? we have <3s too. now before i run off and do calculus, let me explain something.

The CVS camcorder. I’ve got it rigged up USB and plugged into my Mac/Linux/whatever. It is not recognized which sucks. But, by holding down the record and delete keys while booting up, you get a system info menu. This reveals only a little (but some) information about the camcorder. It’s probably helpful to some people. Thursday at the meeting we’ll discuss how to get it rigged up with proper device drivers, etc. I’ve been talking with some people about getting DD out there because they’re needed. This isn’t as easy as all of us thought it would be!

In other news today, PSP 1.5 firmware is now open and “cracked”. You can run homebrew apps on your PSP finally. Check it out here.

The poor man’s U2 iPod has now been made. It’s basically throwing the U2 stuff on a regular old 30gb iPod. Cool none the less. I like the U2 iPod’s look a lot. [francis]

This is pretty cool too. It’s been around for awhile but it’s a full out project that deserves some recognition. It’s a MMOG version of GTA. Lotta C++ skill there. [xrosesxarexdeadx]

Your lazy afternoon hack: Beat the heat with a homemade air conditioner

I’ve gotten about 20 e-mails about homemade air conditioners and what not. So thanks to everyone sending them in to beat the heat. Ghetto-esque, but looks pretty cheap and effective. It’s done by shoving tons of ice water in a trash can, hooking it up to a fan to take in all the warm air and transfer the heat to the water. Then all warm water is pumped outside to…well, get rid of it. He says it cost $30 CAD to make so that’s not too bad at all. Someone try it out and let us know how it goes. You obviously must be pretty hot, but hey, if I hadn’t gotten this free A/C from my aunt/uncle, I would be building one of these in 5 seconds in my kitchen. Very nice.

Thanks [steve]

18 thoughts on “Hackaday Lazy Afternoons

  1. It works great. I’ve built one like this and another which uses JUST the trash can and a large bubbler to decrease the air temp using evaporative cooling. This coil method works great though if you can drain the water. He used pretty big copper in this one, you should grab some smaller AC copper from home depot. It will cool a lot quicker due to the larger surface area. Just coil more smaller stuff then you would the larger.

    Also, LEAVE GAPS IN THE COIL! Do not fully cover the back. You want at least 1/4 inch of gap between the coil so that the air is drawn OVER the coil rather then just being sucked in from the sides.

  2. im totaly doing the ghetto air cooler, it gets pretty hot in my room because of bad isolation and this would be great.

    but wouldnt it be better to put the water resevior in a place wit lots of shadow, like under your bed, you have those rolling things for under your bed just plastic bins with wheels.
    you normally put stuff in them but whater would work to.

    i think this one would do quit nice
    the bed roller

  3. The bucket ‘o’ ice trick only works if you go to the gas station and grab a few bags of ice. If you use your freezer to make the ice that cools the kitchen it does no good, as it is drawing heat out of the water and putting it back into your kitchen. would you then cool your kitchen with it? That works as well as leaving the door to the freezer open. now if you could just use your neighbor’s freezer…

  4. Billy: I think its more the fact it blows the cool air onto you. Yes, it will actually end up warmer in the total, but the important thing for most people is just the fact it WILL blow cool air.

    I’d close loop the system, add a peltier and stick it outside.

    I’m actually in the process of a desktop peltier cooler. YES IT WILL HEAT UP THE ROOM. I understand that, but it will be very slow and i’m not using it in a closed enviroment. I just want cold air to blow on me :P

  5. While I’m probably wrong, a thought occurred to me–

    Assuming that you were freezing your own ice/colder water for this system’s input, would try adding a salt, whether sodium chloride or something like propylene glycol, etc. The salt would lower the water’s freezing temperature, possibly providing quicker results.

    * This is assuming that your/your neighbor’s freezer actually cools/chills below 32F/0C.

    With table salt in the right concentration, 20F is easily reachable. Plus, table salt is cheap, especially if you’re on campus.

    Keep in mind that you wouldn’t want to drain salty water into a garden, etc, so semi-closing the system/re-using the fluid would be a good idea.

    *Also, what about using a small radiator/heater core somewhere in the system?
    For example, using a radiator-style transmission cooler submerged in the tank/trash can may increase thermal transfer speed or capacity.

    Think of it like this:
    Generally, when a larger radiator is installed on a car, the cooling capacity is increased– the motor generally runs cooler.

    -It’s that whole surface area thing.

    Feel free to correct me- I’m not a physicist or Materials Engineer.

    -Hack on!

  6. Draining the water outside seem at best unnecessary, and at worst counterproductive. Unless the water is warmed completely to room temperature after its transit through tubes, then draining the coldish water back into a second bucket inside the room would actually get the room colder than draining outside.

    Like billytheimpaler said, this hack is useless if you’re cooling the room that you’re making the ice in. The only thing the fan and tubing thing does is move the cold air around, which may be nice for sticking your head in front of, I guess (some places in fact sell these little fans that you fill with water and stick in a freezer).

  7. First of all, I must say I suck in physics… and can someone explain me, why the copper tubing is coiled along the back of the fan? I thought that if you put in the front, the tubing will be actually getting warm faster… If the flowing water makes the area (near the tubing) colder, then it is better to have the fan blowing at it, cause we’ll get a better air exchange… Blowing air actually won’t make the water colder but warmer, and that would be a good thing, right?

    I know I’m maybe a noob… but correct me if you can. And sorry for my english.

  8. courtesy of boingboing:

    Pinouts for CVS’s “disposable” camcorder
    CVS Pharmacies sell a one-time-use camcorder that you have to bring to their shop once you’re ready to get your videos, which are delivered on DVD. Enterprising hackers are racing to reverse-engineer the camcorder so that they can extract their own video and make multiple uses of the camera without paying repeatedly. A hacker has posted the pinouts for the camera on a Linux site, so victory is surely in hand:
    Here is the pinout for the CVS one time use camcorder. Pin 1 starts at the end where J5 is printed on the PCB.
    1 no connection
    2 ground
    3 no connection
    4 Battery + (probably used to verify the battery level when recycling)
    5 no connection
    6 USB +5V
    7 ground
    8 USB Data +
    9 USB Data –
    10 ground

    Pins 6 – 9 is the only pins needed to connect to a USB port.

  9. Big tip for the PSP swap trick: Hold the memory stick down before you press the button, and release the stick JUST BEFORE “PSP” pops up on screen. The only part that relies on speed is the eject, I think. And I’m pretty sure that it doesn’t work on all homebrews, so try it with more than one. I know NesterJ works, and I don’t think SNES9x does.

  10. The ghetto AC is kinda lame for a lot of reasons. His thermo prof should give him an F.

    a) keep the water instead of dumping it. The water definitely hasn’t heated up to room temp after going through that little bitty coil. You can definitely sink some more heat into that water.
    b) A fishtank pump would circulate the water better and you wouldn’t have to suck on a hose to start the thing up. Plus you could keep the water by simply pumping it back into the holding tank.

    Water, unfortunately, sucks as a coolant system. You have no real way to cool the water back down. Can’t just use a radiator outside to cool it down, because the outdoor air is presumably hotter than the indoor air and therefore hotter than the outgoing water. You might be able to actually bury a car radiator several feet underground and run water through it to transfer heat into the ground, but likely you won’t get the water very cool this way. Adding bags of ice is your best shot, but simply dumping the water after one run through the system is just inexcusable. You’re dumping your cold water outdoors! Insanity.

  11. Priest, nice find. Now all I need to do is buy some cold packs and velcro them to my desk fan. I dont need the whole room cold, just me (and my mule of a pc)

    Ohh, and the best place for cvs camera/camcorder info imho is linux-hacker.net’s forums.

  12. I’d use a regular size bucket, a six pack of frozen water bottles and a small pond pump. Recircluate the water through the buck and refreeze the bottles as needed, or even keep a second or third set of bottles to swap out. It may not cool the room for as long and cost a little more, but would probably be similarly effective.

    Of course I already have a pump lying around and a small heatercore that could also be used from my watercooling days.

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