Levoit Core 300/300S activated carbon insert

Update 1

Added a 6x3 magnet version for the carbon container, you will not need the turning tool anymore and instead will need to source 8 to 10 6x3 magnets. Removing the lid can be easily done by using some tweezers inserted into the infill used as lever. Using magnets for the center point is optional as the 4 on the sides provide plenty of holding power

---

After noticing my Levoit Core 300s purifier had its filter depleted, and since I already have a bag of activated carbon for my 3d printers, I tried to look for some kind of container that would allow using my own media as filtering material. 

After printing this model I noticed a number of issues:

• the carbon container versions were too small to effectively have air circulating through them
• the lid closing mechanism was extremely brittle and the tiny legs snapped off on the first fitment
• it was designed for a diy filter that doesn't use the Levoit upper piece (the one housing the fan and all the electronics)

So I just took some time to design the insert from scratch, starting off the same base concept of the referenced model, but with the following improvements:

• ensure all air passes through the carbon container
• closely fit around the protruding fan protective plastic piece
• properly close the container using a printed thread

Here's the result (the hexagonal mesh is for display only)!

here's a cross-section while integrated

Parts

The filter consists of 4 parts:

• stand - puts the carbon media as close as possible to the fan, allowing air to pass from the bottom
• base - houses the carbon media and wraps all around the fan, forcing a predefined air path
• lid - secures the carbon media
• turning tool - allows an easier opening/closing of the lid, and doesn't occupy precious vertical space when the insert is installed

Printing

Print the stand and turning tool as normal, the base and lid will need a mesh to be added in the slicer as it depends on how big your carbon pellets/shards are. Split your two pieces into parts (not objects), select the proper element from each and set the following printing options:

• 0 bottom layers
• 0 top layers
• 20-30% infill (I personally chose 24% as 22% would leave some carbon to pass through, do some tests by just printing the lid)
• honeycomb pattern

Pictures for reference

And you are done!

Assembly

As per the cross-section image, just fill your carbon container, close it, put the stand first into the filter element, and put the carbon container on top of it

Results

While this mod doesn't replace the hepa or mesh of the filter element, I find that it is very effective at absorbing odors and fumes. Better quality carbon with more absorption will be more effective.

As a sanity test after the container is installed, turn on your filter at max power and you should hear the carbon being literally lifted towards the container lid by the strong fan!

Sourcing the carbon pellets

Not all carbon is created equal, this guide for the nevermore filter is pretty detailed and will give you all the information needed → https://www.printables.com/model/1076490-additional-activated-carbon-for-air-purifier

For people located in Italy this is what I use for all my carbon filters → https://www.amazon.it/gp/product/B098ZXF4BK?ie=UTF8&th=1 

Happy filtering!