Introduction: 5 Minute Swamp Cooler - Evaporative Cooling on a Floor Fan!

The Robots Everywhere shop took the brunt of a brutal heat wave in northern California a week ago, and given the normally mild temperatures up there on the coast, never really needed air conditioning. Being the creative makers that we are, instead of going out and buying inefficient floor or window air con, we decided to add some cooling to our floor fans with this very simple build.

This little trick actually acts as an evaporative cooler; the ice will melt into the fabric, and then be evaporated off - this will create more heat differential in the moving air than just the melting itself.

A warning to those who live in areas with higher ambient humidity: add a drip catcher between the cloth and the motor to avoid any chance of a short. Swamp coolers are designed for very dry climates, and the meltwater will evaporate fast enough to not saturate the towel enough to drip into the fan, but it's something to keep in mind.

If you'd like to learn more about what we're doing in the shop, hit up


  • A Fan - any kind of fan will do
  • Cloth - a towel, a rag, an old shirt, pillowcase, again - anything is fine
  • Two thin, stiff rods - we used plastic tubing, but plastic coat hangers, heavy (10 gauge etc) baling wire, dowels, and anything else that will hold up straight will work.
  • Wire and/or zip ties - to attach everything together
  • Ice - the secret ingredient!

Step 1: Attach Fabric Shroud to Tubing

Start by poking your wire hooks through the corners of your shroud, at the end you now designate "front". Hook it into the end of the tubing, as shown.

If you are not using tubing, and your rods are solid, use some duct tape on the wire, or replace the wire with a zip tie. If you want to get clever, you can also make a grommet hole in the two front corners of your fabric, and set grommets there. Once set, you can use a string, baling wire, or zip ties.

Or you can just wrap it all in duct tape.

Step 2: Add Shroud to Fan

This step is simple; put the two tubes through the grill of your fan, making sure THEY DO NOT INTERFERE WITH THE FAN BLADES. If the fan blades hit them, this is going to be bad, so spin the fan by hand to make sure!

Give the tubes room to extend out the back, to help stabilize the assembly (see 4th picture). The tubes can even go as far back as to touch the floor if you want.

If you need help keeping them in place, use your zip ties.

Step 3: Add Ice!

Put some ice in the shroud, in front of the fan. More ice = more cold.

Enjoy your colder air!