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 https://www.robots-everywhere.com

Supplies

• 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!

Comments

[Cat00x]

I wonder how you could do this with a box fan? Maybe have a cloth angled down the back side with a “pocket” for the ice?

[RobotsEverywhere-Riley]

I'd just do it pretty much the same, installing the tubing on the sides of the grill and putting the shroud over the front of the fan. I am fairly sure having the ice over the exhaust rather than the intake is relatively moot, as it's the same airflow.

[JohnC430]

ICE? how much power did it take to make the ice? Just plain tap water would do almost as well! This is "engineering"?

[Mullumnic]

The cooling of the air comes from two phase changes of the water; solid - ice, to liquid -water, and then to gas - water vapour. Using a fridge as the ice maker, adds, assuming it’s not in the same room, the largest cooling part of the whole scheme. To change water from liquid at 0C to solid at the same temperature, uses, or gives back, the same amount of energy as heating it from 0C to 80C. Removing this, therefore cuts out, more cooling than one would at first think. This is “Physics” ;)

[RobotsEverywhere-Riley]

Yep! It's not an efficient system, it's one based around time and ambient temperature as important variables. You can make ice when it's cool and power is cheap and use it later. You're not going to turn your fridge off either way (at least most of us store food in it) so there's 0 maintenance waste to KEEP ice frozen.

[RobotsEverywhere-Riley]

See, there's a concept you're missing, known as "storage". In this case, you can use power to make ice when it's cool and inexpensive (night) and use that cooling when it's hot and power is expensive (daytime).

[TamaraK27]

Did you make a video? How much does it cool the air? I tried something similar and it was completely ineffective. Did you make a tutorial? I dont understand the tubing tied to the fan part.
i saw a video where a gentleman turned box fan with blowing side up into his attic and left it secured laying face up into attic access the square moveable panel in the hallway or front closet. Then he shut all doors and windows except one where he had taken the screen off the window and made same sized aquarium filter plastic see through fiber and had an aquarium water pump in a rectangle sealed planter box filled with water under the window the aquarium tubing he poked holes in and ran it along the top of the now window filter fiber used in place of reg screen..and sunk the pump in the water and when he turned it on..that tubing would trickle down inside that filter fiber ( kind of looks lije a scrubby pad for dishes only a 4ft by 2.ft piece, that water keeps the filter screen cool and because the fan is sucking the air from inside the house out through the attic it pulls the outside fresh air through that water cooled fiber screen and it cools like an a.c. please give me any video links as i am thick headed and a blockhead when it comes to directions ...thank you ...brilliant idea im excited to try it.🌎✌🕊

[ericocean]

I always love low tech 'old world' solutions. Yours is great and now on my list for when the heat returns (and I hope that is sooner rather than later!)

[seamster]

Simple and clever, but effective for a little extra cooling. I like this idea, thank you!