If you find yourself experiencing an unexpected heatwave and your air conditioner goes down, keeping cool can be difficult. While nothing beats the cool blast of air supplied by a traditional AC unit, there’s a DIY approach that can help out. Making your own swamp cooler for emergency use is a simple project with just a few tools and materials.
What’s a swamp cooler and how does it work?
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A swamp cooler, also known as an evaporative cooler, pulls air into a container and over water or ice, causing an energy exchange in which the heat in the air is absorbed by the surface of the ice or water, cooling the surrounding air. This process is known as “evaporative cooling,” and works a lot like sweating does on your body. You can purchase a swamp cooler, or make one yourself relatively inexpensively. The DIY set-up uses a cheap commercial fan to pull air across ice or water to accomplish the evaporative cooling result.
While a DIY swamp cooler does work to cool the surrounding air as much as 15 to 40 degrees F, it’s not as effective as AC, and will work better in a smaller space. Since you’re using a fan to power the system, the swamp cooler can only cool air as fast as the fan can move it. Rather than trying to use it to cool an entire home, choose one room that you can cool off—you’ll get a better result. Swamp coolers also need to be cleaned frequently to prevent mold. While a DIY swamp cooler probably won’t work for extended use anyway, you should clean the inside of it every couple of days to keep mold and bacteria from forming.
Also important to note: Swamp coolers will not provide relief in areas with high humidity, since they add humidity to the room.
The container method
The best container for a DIY evaporative cooler will be insulated, although some people have success with a five-gallon bucket. In general a foam cooler is the simplest container for your ice because it’s insulated, but also easy to cut.
The important thing is to have about five gallons of capacity for your container and a lid. Aside from ice and a cooler, a small fan that can be attached to the lid of the container, as well as two PVC elbows about two inches in diameter.
To construct your swamp cooler, cut a hole in the top of the cooler just a little bit smaller than your fan. If your fan has a square case, you can cut a hole the size of the turning blade, and rest the edges of the fan on the top of the cooler. It’s a good idea to glue your fan in place, but you can also use tape if that’s what you’ve got. Next, cut one hole for each PCV elbow about four inches up from the bottom of the container. Glue or pressure fit your elbows in place and then put your ice in the bottom of the cooler and replace the lid. Your swamp cooler should be ready to use.
While some people swear by using frozen bottles of water instead of loose ice in your cooler, it will work better if there’s water in there too, since evaporation is how the air gets cooled. Using frozen water bottles to cool the water down instead of ice will make them easier to change out, but you’ll always need a reservoir of water for it to work.
The box fan method
There’s also a method of construction using a box fan.
This construction is a little more tricky, but it does move more air. For this method, you’ll need a bucket, a water pump, some window screen, some flexible tubing, and some specialty evaporative fabric.
To make this version, cut the screen and the fabric to the same size as the box fan. Place the screen on the back side of the fan and then layer the fabric on top. Attach the screen and fabric to the fan using zip ties or wire. Attach the tubing around the edge of the fan using the ties or wire, leaving a foot or two of tubing at one corner to draw water from your bucket. Poke lots of holes in the surface of the tubing around the edge of the fan like you would for a soaker hose in the garden. Fill your bucket with water and attach the tubing to the pump, placing the pump in the bucket, and clamp the end of the tubing not attached to the pump closed to force the water out through the holes in the tubing. Flip the switch to turn it on and make sure that you have it set on a waterproof surface or add a drip pan of some kind to catch any excess water that might occur at the base of the fan.