The iterations I made so far and it seems the final version already is that I made it smaller, I used lower powered but bigger cpu fan. I like the bigger fan because it has bigger blades and with bigger blades, it can suck in air more easily on a wider area, I sacrificed the higher power to get rid of the noise. And the last revision I made is to glue all parts except the door for changing the filters and removing the bag of activated carbon. I also got rid of using multi-filters because those unnecessary filters were useless, I found this out during my testing of the industrial grade air filter I made. So now, I only use hepa filters. These filters can remove particulates in the air even those PM2.5 class particulates where harmful chemicals and air borne viruses and bacteria belongs.
I also added a third motor which can be detached from the fan when not needed. This third motor will allow the air purifier to catch more air as far as 3 meters so that means the space that it can help clean was widened from a mere 18sqm to about 25-30sqm.
Here is the new air purifier:
Here is the extension module:
The design failed because of only 1 reason: it does not have enough activated carbon in it and most of the air wont pass through the activated carbon. It is also very expensive.
My original design was very effective at removing air particulates and odors because the air has to go through a very thick layer of activated carbon which is about 50mm thick and there is a chamber where the air goes and will not have a choice but to go up and pass through the activated carbon.