Introduction: 3D Printed Coffee Filter Evaporative Cooler

About: Innovative Projects, Diy's, Life Hacks

This will be the 3rd year I am using a 3D printed coffee filter air cooler.

It can cool the air by evaporating ice-cold water.

Does it work?

100% -Yes

But.......There are a few things you should know.

It's not an air conditioner. Don't expect the same results.

Can you actually cool a room with it?

Yes, but only so much. With the correct setup you should be able to drop the temperature a little bit.

With a single fan air cooler you will not cool the room, but you will cool your face :)

It's great to keep on your desk.

If you want to be serious about the cooling, start with 3 fans.

In my previous apartment I was able to drop the temperature by 2 ºC (35.6 ºF) in one of the rooms.

This year I have moved and my workshop is a little bit bigger.

So far a single triple fan cooler can drop the temperature by 1 ºC (33.8 ºF). I am planning to make another 3 fan cooler.

Evaporative coolers are also humidifiers, so keep that in mind.

I have a window fan blowing the air/moisture out.

If you shut the windows and doors (especially in a smaller room) the humidity levels will rise.

It will not feel very nice in the room.

Consider adding a window fan, even if it's a small USB fan.


Apart from a 3D printed filter holder, you'll need a 120mm fan.

There are 12v or 5v USB fans.

Whatever you choose, go for high airflow or high rpm's.

You'll also need size 4 coffee filters and a water container.

Step 1: Print the Filter Holder of Your Choice

There are 2 versions of the filter holder you can print. A solid - support-less cube or a cube that you need to put together from 4 pieces.

Step 2: Fill the Box With Coffee Filters

I filled the box with coffee filters the narrow side facing the fan.

Stapler is all you need to keep them in place..

Step 3: Add Bottom Filters to Feed the Water

I cut a filter opened and used it to feed water to a pair of filters.

Step 4: Add a Fan

I used 8 zip-ties to hold the fan. I could have used 4, but I think double head zip-tying looks better.

You can also use screws.

Step 5: Put It on Top of a Water Container

Fill a bucket/container with big chunks of ice and top it up with water.

Now put the box on top submerging the bottom filters into the water.

In this example the container was bigger than the filter-box, so I cut a hole in the lid to hold the box.

Step 6: Wet the Filters or Wait

I keep a spray bottle in the fridge to wet the filters with cold water whenever it's needed.

You don't have to wet them if you don't want. 15 - 20 min and they will be wet on their own.

Step 7: Connect/Add a Power Supply and Turn It ON