Air Filter

SAFETY WARNING: this air filter is built with a “something better than nothing” mindset. It's a temporary, cheap solution and you may need to modify and/or improve the filtration system in order to sufficiently clean the air from your 3D printer. 

Creating an air filter is not as easy as I thought before starting this project. There are many things to study and try. The most difficult and important part is achieving good suction without choking the airflow while still effectively filtering out pollutants.

To build this air filter, I used:

- A 120mm fan, 39mm deep, which has an airflow of 234,4 m³/h - Amazon link: https://www.amazon.it/dp/B00MNJDNQY?psc=1&ref=ppx_yo2ov_dt_b_product_details

- A common switch
- A standard 12-volt power supply
- Two activated carbon filters, pre-cut for litter boxes - Amazon link: https://www.amazon.it/dp/B0BNL4Q275?psc=1&ref=ppx_yo2ov_dt_b_product_details

- Two layers of non-woven fabric (outer and inner layer from a surgical mask)

My filter is used inside a cabinet, so the air is recirculated. A filter that needs to recirculate air must be assembled differently than one that expels air into the environment. You can assemble your air filter according to your needs.

For my recirculation system, I assembled the layers in this way:

From the side where the air is drawn in, there are first the two non-woven fabric filters, then the two activated carbon filters, followed by the thin protective grill, and finally the fan.

If your filter expels the air into the environment, you need to put the fan first - as suggested here: https://www.alveo3d.com/en/product/hepa-h13-filter-p3d/

I don't have a measurement device for the air quality at the moment, so I can't say how much effective it is. 

According to ChatGPT 4, activated carbon filters are effective at absorbing a variety of harmful substances emitted during 3D printing. In the context of a 3D printer using PLA, PETG, and TPU, activated carbon filters can absorb the following compounds:

1. **Volatile Organic Compounds (VOCs)**: These are produced during the printing of plastic materials and can include substances like acetaldehyde, formaldehyde, and other volatile compounds.

2. **Ultrafine Particles (UFPs)**: Although activated carbon filters are not specifically designed to filter particles, they are often combined with other filtration layers (such as non-woven fabric) that can trap ultrafine particles emitted during printing.

3. **Odors**: Activated carbon filters are very effective at absorbing unpleasant odors produced during printing, which are often associated with VOCs.

4. **Fumes and Chemical Vapors**: During the printing of PLA, PETG, and TPU, chemical fumes and vapors can be released, which activated carbon filters can absorb, improving the surrounding air quality.