The following instructable is going to show my take on the 5 Gallon Bucket Air Conditioner/Swamp Cooler. In the picture you'll notice a small solar panel attached. I'll be creating another instructable on how to hook up a solar panel to a USB cable so you'll be able to power your bucket with solar energy. For now, this will just be about how to build an efficient bucket that actually works.
In contrast to the viral video on Youtube of the guy that built the original swap bucket, I've made a few changes to the design to make it more practical. I noticed when I first built the bucket exactly like the guy on Youtube, the ice would melt extremely fast due to the high powered fan pushing a lot of hot air past the ice. Also, a 5 gallon bucket full of ice does not provide enough of a temperature drop to cool entire rooms. And then there’s the mess that the ice leaves behind. In order to achieve maximum effectiveness, the cold air inside the bucket needed to be concentrated and aimed.
This bucket is best used when you are just sitting around and would like a cool breeze on your face. I use it when I’m on the couch watching TV, on my computer getting work done (more like playing video games), or on warm nights when I go to sleep. I hope this instructable is straight forward and easy to recreate. This is my first one ever so please be sure to leave a comment. Thanks :)
Now lets get started.
*Before we get started, I would like to reiterate the purpose of this bucket. This type of air conditioner is intended for small personal applications. It is not practical to be able to cool entire rooms with a 5 gallon bucket full of ice for hours on end. It is thermodynamically impossible to do so. This bucket is basically the equivalent of your car's AC on "low" on its coldest setting.
Step 1: Gather Your Materials
For this project you are going to need the following materials:
(1) 5 Gallon Bucket
(1) Foam 5 Gallon Bucket Liner*
(1) 2" PVC pipe cut 2.5" long
(1) 5v USB powered fan**
(25) Large Plastic Popsicle sleeves
(1) 1 Gallon Jug
You will also need the following tools:
(1) Cordless Drill - doesn't need to be very powerful but the more the merrier
(1) 2 3/8" Hole Saw***
(1) Hacksaw/PVC cutters if you don't get the pipe cut for you
*The only place to get these are at Home Depot and unfortunately they only come in packs of 3 and they have to be preordered online
**CPU fans push the least air and are very weak, mini desktop fans with plastic blades are a bit stronger, and fans with metal blades push air the fastest
***If you don't have a 2 3/8" hole saw or don't want to buy/cut a long piece of 2" PVC pipe you can use a 2 1/4" hole saw and use a 1 1/2" S x S PVC coupling to fill your outlet
Step 2: Drill Your Hole
Hole placement on your bucket is one of the crucial factors in getting it to blow cold air. You want to get the hole as close to the bottom as you can but leave some room for perspiration build up that will occur on your popsicles. The bottom of your hole should be between 2" - 2 1/2" from the bottom of the bucket. Shave off the hairy plastic with your knife.
After that, insert your foam bucket liner and center it inside your 5 gallon bucket. With your off hand, stabilize the inside of the bucket by pressing down in the center. Then, stick your hole saw through the hole you just drilled and drill another hole through your foam bucket liner.
Lastly, insert your PVC pipe into the holes you just drilled. It should be air tight and you may need to rotate your pipe back and forth to get it in. Don't put it in too deep though. You want the PVC pipe to be flush with the inside of your foam bucket liner, otherwise you will create an air flow problem.
Step 3: Mount Your Fan
Now we are going to be mounting our fan to the top of our foam bucket lid. This depends on the design of your fan so this step might be a little different from person to person. If you are using a desktop fan, you're going to want to first take it out of it's mount. Typically this process usually just involves a screwdriver and two screws on either side.
Next, place your fan on top of your foam bucket liner lid. If you are using a desktop fan you're going to be resting your fan on top of the foam bucket lid so draw an outline of your fan and then compensate inwards about a quarter of an inch so that the blades will be able to sink into the bucket and the lip of the fan will rest on top. If you are using a square CPU fan simply draw an outline and then cut.
Lastly, make the cut. It's best to play it safe and cut a little short at first since foam is very easy to cut. Use a sawing motion with your knife and whatever you do don't break the lid (no pressure). Replacement lids aren’t readily available so be careful.
Set your fan on or inside your lid and you're done with the construction of your 5 gallon bucket air conditioner.
Step 4: Prepare Your Fuel Rods
Now it's time to get over to the sink and start filling up the popsicle bags full of water. This is a tedious process and will test your will and inner strength as a human being. It's a simple process and goes as follows:
- Take a popsicle bag and put it under the sink faucet as if it were a water balloon
- Fill the bag to about 3/4 to the top
- Add salt*
- Tie off the popsicle bag with a knot/rubber band/plastic sealing device
- Put it in the freezer
- Repeat Steps 1-5
- Fill your gallon jug up with salt water and throw it in the freezer
Something to note: popsicle bags have the problem of losing their upright integrity as they melt. A hypothesis I have that I haven't been able to test yet is putting thick plastic straws inside the popsicle bags to keep them upright and stable.
*Salt lowers the freezing temperature of water, allowing for colder ice. Be careful not to put too much ice though as the water will not freeze if there is too much. The temperature of freezers varies so there's no accurate amount of salt to recommend. I suggest doing some test runs of your own to see what works best.
Step 5: Fill Your Bucket
After you've frozen your popsicles it's time to place them inside the bucket. Because of the nature of thermodynamics, you're going to want to try and maximize the amount of surface area you get from your popsicles. The best way I've found so far is to place the base of each popsicle stick towards the center of the bucket and have them lean on their edge against the outer interior wall of the foam bucket liner. That way only 2 small points of the popsicles are covered and the rest is open and available for air to pass through.
After that, plug your 5v DC powered fan into anywhere you've got a USB socket and let her rip!
Step 6: Enjoy Your Cool Air
If you did everything right, you should be outputting anywhere from 5-10°C (My thermometer is in Celsius, 41-50°F) depending on how much salt you used in your popsicle sticks and your freezer settings. For longer lasting results I recommend using the gallon jug with salt water along with 6 popsicles near the output of the bucket and rotating out the popsicles as they melt.
After you're done basking in the glory of your creation, check out my instructable on how to connect a generic 5v solar cell to a type A female USB connector and start connecting devices from the fan on your bucket to the cell phone in your pocket (Coming SOON :D).