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Homemade Air Conditioning

Discussion in 'General Survival and Preparedness' started by Quigley_Sharps, Jul 27, 2006.

  1. Quigley_Sharps

    Quigley_Sharps The Badministrator Administrator Founding Member

    Geoff’s Original Homemade Air Conditioner

    By Geoff • June 15, 2005
    Note that this was my very first attempt at homemade air conditioning, preserved for posterity -
    if you’re planning on building your own, take a look at my main page or my final design, the Black Beauty.


    Salvage from around the house a:
    • large fan
    • garbage can
    Grab from Home Depot:
    • 25 feet of 1/4 inch outer diameter (OD) copper tubing (~ $14)
    • 20 feet of 1/4 inch inner diameter (ID) vinyl tubing (~ $6)
    • a package of zipties (~ $3)
    • 2 small hose clamps (~ $1)

    Here’s the basic setup. The garbage can is filled with ice water, which is then fed by gravity (a siphon) through the copper tubing coiled along the back of the fan. The hot air passing through the tubing warms the cold water, cooling the air. Waste warm water is then pumped outside.
    The system will cool an average room to a comfortable level in approximately 15-20 minutes. Depending on flow rate, a full bucket of water will last approximately 1-3 hours. I use a single bucket before bed on hot nights, which lets me get to sleep. Once the water runs out, the house has cooled off enough that the fan alone provides sufficient cooling.

    It doesn’t rip quite as hard as central air, but for less than $25 CAD I’m not complaining. (and, btw, that’s my girlfriend’s makeup mirror, not mine)
    The main factor affecting the performance is the temperature of incoming water. Cool water will work, but ice water will result in a cooler room, quicker.
    Add salt to the water if you’re adding a large volume of ice, as this will drop the freezing point of the water and increase the cooling effect of the fan.
    You can attach the tubing to the front of the fan as well. This will increase performance, just make sure that your fan can handle the additional torque of tubing full of water attached to the front.

    Here’s what the fan looks like from the back. The biggest issue in construction was uncoiling 25 feet of copper tubing in a 15 by 20 room. Just be patient and don’t attempt to bend the copper too severly, it’ll fold over on itself and you’ve effectively chopped your nice copper tubing in two.
    When coiling the copper into a spiral on the back of the fan, I started in the middle and put zipties every 15-30 cm (6-12 inches). Use your discretion, you want to preserve the spiral shape and keep the tubing as close to the metal mesh as you can. If you’re a bit crazy, sand the paint off the back to improve heat transfer from the metal mesh.

    It doesn’t really matter how it looks as long as it’s reasonably spaced out and consistent. A hint for construction: prebend your zipties into a J shape. Then you can hook them easily in and back out of the metal mesh on the back of the fan. I’d suggest cutting off any extra plastic once you’ve got them on.
    Some have suggested using an old car radiator attached to the front of the fan instead of coiled copper tubing. Cost prevented me from trying this, but as long as the head loss from the radiator is low enough to allow the siphon (or pump) to operate, this should increase the performance (better heat exchange). You’ll likely have to construct a frame to hold the radiator in front of the fan.
    If you look closely, you can see the condensation from the incoming icewater, but no condensation on the tubing leading out. This is perfect, as it means that heat is being transferred from the room to the water.
    Once you’ve got the copper tubing coiled, the rest is easy. Cut your vinyl tubing into 2 pieces, with one about twice the length of the other (one piece 6-7 feet, other piece 13-14 feet).

    Attach the shorter piece to the incoming side of the copper tubing. It should slide relatively easily over the copper, but be snug. Attach the hose clamp and tighten. Following a similar procedure, attach the longer piece to the outgoing side of the copper tubing. (I don’t believe it really matters whether you feed cold water from the inside or the outside. It’s up to you to run some numbers.)
    Submerge the shorter end of the vinyl tubing in the garbage can (washed and clean). I suggest weighing down the end of the tube, to avoid it drawing in air and stopping the system. I used twist-ties to attach a thin rock to the end. If you have fishing weights, I would suggest using those. Then again, if you have enough stuff for fishing weights to be lying around you can probably afford a real air conditioner.
    Next, hang the longer tubing out your window. For the gravity pump to work, the end of the tubing must be below the water level of your garbage can, plus an allowance for head loss in the pipe. Just to be safe, get it as low as you can. I’d suggest arranging it so the waste water will feed into a garden, but student ghettos don’t have gardens so in this picture it’s being fed into a drain by the basement.
    I had to poke a small hole in my screen for this to work.

    To get the system started, make sure the vinyl tubing in the ice water is completely submerged. Then, bring the waste water tubing as low as you can and start sucking on the tube. If you’ve ever siphoned gas you know the drill.
    Basically, suck as much as you can. Then plug the end of the tubing with you thumb, and repeat. You’re done when you start tasting water. Just let go, and it should continue to flow normally.
    I’ve also hooked this up to a garden hose as the cold water feed. Check out the improved water supply.
    • <LI sizcache="23" sizset="13">A closed circuit version of this is entirely possible. An example can be seen here.
    • I would also suggest constructing a geothermal heat pump. Dig a deep hole near the window, the soil at this depth will be quite cool. Bury a coil of copper tubing spaced well through the soil, this will act as your heat sink. Pumping water from the fan coil to the underground coil and back will exchange heat from the warm room to the cold soil. I’d love to implement this, but my landlord may not take well to large holes in his backyard.
    • I realise small air conditioners are quite cheap. But then you don’t get to build anything!
  2. E.L.

    E.L. Moderator of Lead Moderator Emeritus Founding Member

    Cool idea. I think I will stick with my central air, but hey you never can tell when you have to make do with what you have at hand. Good idea.
  3. Quigley_Sharps

    Quigley_Sharps The Badministrator Administrator Founding Member


    Pete’s Homemade Air Conditioner

    By Geoff • June 15, 2005
    Credit goes out to Pete H. in sunny England for this great build. This version of the homemade air conditioner removes the need to drain water outside by using an aquarium pump, and sits on a rotating base. Check out more homemade air conditioners here.
    Here’s the overall view of the unit. You can see the insulated polystyrene box containing icewater and the aquarium pump, along with the fan and attached copper tubing.
    Pete did a much neater job of attaching the copper tubing to the front of the fan than I did. Using copper tubing on both the front and back of the fan is a great idea, the more copper tubing, the more heat exchange possible.
    Here is a view of the unit from above, allowing us to see the copper coils on both the front and back.
    Here we can see the entire system on its rotating base, allowing directional cooling (most) anywhere in the room.
    This picture shows Pete’s innovation, the Internal Cooler Coil (ICC) ready to be installed. The water first runs through this coil, through the ice water, and then out to the fan. Pete and I are wondering if this actually increases performance at all, but it sure looks cool.
    <SCRIPT type=text/javascript><!--google_ad_client = "pub-0093512796423934";/* 468x60, created 1/23/09 */google_ad_slot = "0251440215";google_ad_width = 468;google_ad_height = 60;//--></SCRIPT>
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    Here we can see the aquarium pump submerged in the ice water. Pete aims to increase the power of the pump, and replace the polystyrene container with something more permanent. A small freezer with its heat vented to the outside would be ideal.
    If you liked Pete’s design, check out Spencer’s heavy duty interpretation, or my final design.
    <TABLE bgColor=#e9e8e3 sizcache="23" sizset="13"><TBODY sizcache="23" sizset="13"><TR sizcache="23" sizset="13"><TD align=middle colSpan=3 sizcache="23" sizset="13">Homemade Air Conditioning Plans and Pictures </TD></TR><TR sizcache="23" sizset="14"><TD vAlign=top width="33%" sizcache="23" sizset="14">Original Design
    Geoff’s Homemade Air Conditioner
    Heat Exchanger Improvements
    Water Supply Improvements
    Technical Notes
    </TD><TD vAlign=top width="33%" sizcache="23" sizset="18">Other Designs
    Pete’s Homemade Air Conditioner
    Anonymous’ Homemade Air Conditioner
    Spencer’s Homemade Air Conditioner
    </TD><TD vAlign=top width="33%" sizcache="23" sizset="20">Final Design
    The Black Beauty

  4. CRC

    CRC Survivor of Tidal Waves | RIP 7-24-2015 Moderator Emeritus Founding Member

    Both very cool ideas...


    My brothers name is Geoff....(spelled the same way..)


    Pete..is my dad.

    Y'all been hanging around their house today????? :eek:
  5. Quigley_Sharps

    Quigley_Sharps The Badministrator Administrator Founding Member

    :D lol
  6. melbo

    melbo Hunter Gatherer Administrator Founding Member

    That is cool
  7. CRC

    CRC Survivor of Tidal Waves | RIP 7-24-2015 Moderator Emeritus Founding Member

    Did you use "Quig's Binoculars "to find that??? :D
  8. Jinker

    Jinker Monkey+

    1 Attach copper tubing to the fan
    I took the grate off of my fan, so I could put the heat exchanger on the inside, hopefully making it look better. Air conditioning replacement I'm using copper tubing as the heat exchanger, although you could use something else, as copper is not cheap, and not easy to work with. As you can see in the second photo, it's very easy to kink the tubing, in which case, you stop the flow of water. I gra…
    [​IMG]Attaching the tubing to the pump
    Now, the cheapie pump I bought would only fit 1/2" ID tubing, and they didn't have anything that would downsize it to 1/4" for me, so I just rigged it up. As you can see in the first and second photos, 1/4" tubing fits quite nicely around the copper tubing. In the third photo, you can see how I just inserted the 1/4" into 3/8", into 1/2" tubing, which would then fit o…

    [​IMG]Submerging the pump and testing it out
    I bought a foam cooler to hold my coolant(ice water), as I have easy (free) access to both water and ice. Once I had it all hooked up, with one tube going from the pump into the heat exchanger, and another from the heat exchanger back to the cooler, I submerged the pump and plugged it in. At this point you'll be able to tell whether or not you have leaks real quick. …
  9. Tango3

    Tango3 Aimless wanderer

    cool! ( har har)
    One of the early version of our chevy "tech vans" had a similarsimple idea; just a tank with aluminum fins filled with dry ice and alcohol a fan blew across the fins. silent except for the fan ...
  10. Seawolf1090

    Seawolf1090 Adventure Riding Monkey Founding Member

    Sounds like the ol' "swamp cooler" concept - does NOT work well in high humidity - like here in Florida just now.
  11. Quigley_Sharps

    Quigley_Sharps The Badministrator Administrator Founding Member

    added pictures
  12. Tango3

    Tango3 Aimless wanderer

    thanks for the pictures. "Very cool" system to tuckaway in the mental file cabinet...[applaud][boozingbuddies]
  13. XR750

    XR750 Monkey+

    Very good idea not sure it will replace central air but it's a good idea.
  14. Jennie_in_Iowa

    Jennie_in_Iowa Monkey+

    I saw a documentary a few weeks ago about a library with a soup-ed up version of this type of cooler. They would freeze the ice at night when electricity is cheap, then melt the ice (with the copper tubes inside it) throughout the day to keep the library cool. Worked pretty slick.

    If you don't have ice, passing air through a wet curtain can cool it.

    edited to add: It 100% replaced their central air.
  15. Knightwolf

    Knightwolf Monkey+

    Rather than just using a pail with water and ice , you may accomplish much of the same process as an AC unit (or a refrigerator ) by using a closed loop system that uses liquid ammonia in much the same way . There was and still is available , a refrigeration unit that operates very much like an electric unit , that has a small burner (yes flame) in the loop that heats the ammonia and this in turn causes the ammonia to expand and then absorb heat in the area around the tubing , I have the plans somewhere for the closed loop system , and I'm sure it can be found easily online and should be able to be converted to a room cooling unit as well . Let me know if anyone gets a unit working , the only electrical part should be the fan . (^_^)
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