Diy Hepa Filter Box Fan. Yes, hepa will provide more filtration, but if cost is an issue than the diy merv 13 box fan is a sensible choice. When i made my first diy purifier, i put the filter on the front:
Within a few weeks, several people told me i was an idiot. 20 by 20 by 1 merv 13 furnace filter; Corsi says that might not be as effective as it seems.
Use one filter for a simple diy box fan purifier:
He convinced other experts to run their own tests. Select a fan you wish to use for your filter. While a genuine hepa filtered air cleaner (which captures 99.97 percent of particles at 0.3 microns) is best, they can be expensive. A merv 13 or fpr 10 furnace filter and tape it to the back of a box fan.