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 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.
Now it’s time to get over to the sink and start filling up the popsicle bags full of water.
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.
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!
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 saltwater along with 6 popsicles near the output of the bucket and rotating out the popsicles as they melt.