Centrifugal Mini Air Purifier with 12025 Turbine Fan, DIY Customizable Filter Media, PM2.5, TVOC, Formaldehyde, Compatible with Xiaomi Filters

2025.8.6 Update: Version 2.0 is out It mainly incorporates suggestions from experts in the comment section and adds a volute air duct The effect is indeed better with stronger wind pressure and concentrated airflow which is less prone to air short circuits compared to the previous dispersed output However when it was first released the fan noise was very loud I tested many versions and finally ran out of white filament before optimizing a relatively quiet version Up close it's slightly louder than V1 but at one or two meters away there's actually no difference Standard V2 and V1 use universal filter cartridges so the configuration file only contains the upper part without the body The body needs to be downloaded from V1

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I bought a children's bed during the 618 shopping festival and when it arrived I found that although it was made entirely of beech and pine wood with no composite panels it still had a strong odor I guessed it was from the chemicals used in the wood treatment process the glue for bonding and the surface varnish Although I'm not in a hurry to move in my daughter is already very excited and eager to play in her room every day Now that it's summer and air conditioning is often on the ventilation conditions are even worse so the idea of DIYing an air purifier came to mind

Why DIY one instead of buying one Because when my home was newly renovated I actually bought two Xiaomi air purifiers After using them for a year they sat idle for over a year until I sold them last year My location is Guangzhou where indoor PM2.5 levels are consistently in single digits throughout the year So this time I wanted to DIY one at a low cost and dispose of it after it absorbed the new bed's odor

Okay the project is approved The first step is to find a mature solution However after a round of searching I found that the current main solutions are either 12/14cm cooling fans or duct fans + Xiaomi filter elements But when I did exhaust purification for the P1S I already made the purifier from the expert "Jindouyun" which uses a duct fan but I felt the airflow was still a bit weak Many users who used 12/14cm cooling fans also reported that the airflow was too small And while looking through everyone's shared experiences I also found that now many third-party so-called double-cylinder filter elements have activated carbon balls inside that are actually made by rolling activated carbon with mud balls And official filter elements are not cost-effective for DIY So using existing solutions is clearly not very feasible

When in doubt ask DeepSeek I have to say DeepSeek is really amazing It used data analysis to explain why ordinary cooling fans have weak airflow and poor efficiency The reason is that although axial fans have a large airflow their static pressure is too low and the process of air passing through filter paper and activated carbon requires more static pressure DeepSeek also provided a core idea which is centrifugal fan + sandwich cylinder and even gave approximate required dimensions (See screenshot)

Then I immediately opened the orange software to look for a suitable fan and finally found a 12025 centrifugal fan also called a turbine fan With a 120 size and 3000 RPM it can generate a nominal 14mm water column static pressure approximately 140Pa which is 7 times that of a Thermalright 14cm fan (2mm/20Pa) There's also a more powerful 24v version 11025 that can generate 180Pa of air pressure but its speed goes up to 4000 and I was afraid the noise would be too loud so I didn't choose it The screw hole dimensions are the same so it's compatible you can try it if interested DeepSeek informed me that the airflow resistance of one layer of HEPA filter paper is about 20Pa so axial fans are really not suitable for DIY air purifiers Only centrifugal fans can generate enough negative pressure to draw external air into the filter element

As for the filter element the outer layer can be a primary filter cotton plus an inner layer of HEPA filter paper with a large amount of activated carbon filled in between If there is a need for formaldehyde filtration it can be changed to activated carbon mixed with potassium permanganate balls which can be flexibly combined according to demand

Printing part There's not much to say about this part Both PLA/PETG printing are fine The printing is simple and completely support-free but it takes a really long time there's no way around it the height is fixed here However if you print the version adapted for Xiaomi filter elements the time is much shorter taking less than 5 hours It only requires 3 M4-10mm screws to install the fan and a little glue to bond the casing

Other materials needed 1 12025 centrifugal fan or the more powerful 11025 24V version (ranging from 20-30 yuan I bought the 20 yuan one) + adjustable power supply (12-20 yuan)

                                    (I only bought the fan because I already have an adjustable power supply You can find sellers who sell the fan + power supply together it will be cheaper than buying the fan and power supply separately When connecting it yourself

                                        connect red to red black to black and avoid short circuits do not connect the yellow signal wire)

                                       2 Three M4-10mm screws (purchase cost 1.5 yuan/50 screws)

                    Filter element part If there are no special requirements directly buy a Xiaomi filter element + print the version adapted for Xiaomi filter elements (Firstly Xiaomi filter elements meet the PM2.5 filtration needs of most people Secondly printing my

                                      filter cartridge really takes a long time and is troublesome to fill with filter media but as I mentioned above the activated carbon in double cartridges might be adulterated so it's recommended to just buy single cartridges)

             For DIY filter cartridge 1 One piece of primary filter cotton just buy the one used for Xiaomi purifiers approximately 4 yuan

                                       2 One piece of HEPA filter paper length greater than 35cm width greater than 19cm approximately 6 yuan

                                       3 4mm diameter columnar activated carbon Make sure to buy those with national standard iodine value 1-2kg fill until full approximately 18-36 yuan

DIY Filling Method:

Purchase reference (what I bought not an advertisement):

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