Oh, boy. During the great California fire of 2020, I went down a very deep rabbit hole looking to air purification. I studied what is out there. I compared their characteristics with regard to filter media quality, air cycles, PM2.5 performance, VOC's, energy consumption, and so on, but my goal was to have performance and near silence. I learned about static pressure and how important it is to choose the right blower for the job (impeller and blower vs fan; and yes, a blower creates vastly more static pressure than these fans). I looked into what quantities of charcoal actually deliver meaningful VOC reduction and how often they must be replaced (you need lbs of it; that single filter on the front of most purification units does nothing but act as a pre-filter). I really should have written all my research and discovery down but if you are serious about it, I came to the following conclusions:

1. A furniture company that decides to integrate a purification system into their offerings can hit it big. Imagine a big, heavy dresser in your bedroom that sucks in air from the bottom and pushes up to the top or a TV stand that where different compartments are filter media. The mass of these reduces noise and vibration and allow for larger, slower spinning blowers and larger surface area of filter media (less static pressure, longer replacement intervals, easily hold pounds of activated charcoal).

2. One needs to pump in oxygen from the outside and exchange the indoor air with the outside air. Circulating and cleaning the air in the home, especially with modern doors and windows, will become unpleasant in a short while, especially during wildfire season. The positive pressure this creates also helps pollutants stay out, if done correctly.

I would absolutely go the diy route using large filters, activated carbon, housed in a wooden box with a blower and implement something like AC Infinity's in-line filtration systems to pull outside air in through a window, with a large carbon filter on one end. Or if a homeowner, set up a more permanent solution. https://acinfinity.com/inline-fan-systems/