I am not a fan of camp fires because I have asthma and it gets hard to breath.
My considered opinion is that most campers have no clue how to build a campfire and they smolder and smoke. I bought a small air purifier/filter the problem is the word small. Not a huge problem if you have air-conditioning but even then there is some infiltration.
Shopping for filters for my Ridiged shop vac I saw a HEPA filter and had an, ah ha moment, large filtering area. This is a proof of concept and if it works I will refine it. And no that is not the HEPA filter it is a conventional filter.
At this point I have an I bolt through the bottom of the filter and suspended with a strap between the pipe and rubber adapter.
Back ground details of the AC as it is now. Sully Creek State Park just south of Teddy Roosevelt National park (the park was closed to camping). The hose with a bilge blower necessary to preventing icing.
How I plan on having this work is that the filter in it housing will work as a stand alone using one of the deck ports or can be connected in tandem with the AC