The image below shows the results of a couple of different configurations of filters and the time taken to clean the air in a highly polluted 1152 sq ft room.
Lasko 20x20 with 3M Filtrete as media
The image below is the configuration in the experiment above where we use two 3M Filtrete 1 inch filters. The “pre filter” is the 3M MPR 300 which is a MERV five It’s there to extend the life of the more expensive 3M MPR 2200 which is a MERV 13. This filter is capable of filtering the air in a 1152 sq ft room in around 30 minutes.
Lasko 20x20 with 3M Filtrete as media
What you need
Fan
The first thing you need is a fan. Any Box Fan fan will do the job. I chose a 20x20 box fan because they’re cheap, they’re everywhere and anything more fancy is overkill.
Pre Filter
The second piece is the pre filter. Note you can use two of these and they do filter the air so if you want to do things really cheaply then just buy the MPR 300 MPR 300 and double them up. This works out at around $5.50 per filter.
Higher MERV Filter
You don’t need to buy a really expensive high MERV or HEPA filter. The MPR 1000 performed almost as well as the MPR 2200 at half the price. The gain in performance from the MPR 2200 isn’t worth the extra dollars.
If money is no object then the best filter I’ve tried so far is the MPR 2200 but it’s quite a bit more expensive than the MPR 1000
Tape
I prefer 3M Shipping Tape because it doesn’t leave any residue when you remove it from the fan and it’s incredibly strong stuff.
Disclaimer / Caveat Emptor
Your situation may vary from mine so please do your own testing and make your own decisions and figure out what works for you.