Triple Exhalaron

https://www.cleanairkits.com/products/exhalaron Or https://www.cleanairkits.com/products/triple-exhalaron-stylish-compact-for-medium-rooms I had one in my old econobox and it cleaned up the car inside air super well during all the bad air days we’ve had. Runs off USB-C so I plugged it into a USB cigarette lighter adapter.

If you're driving a car that you own, then upgrade the cabin air filter to a HEPA filter if you haven't already. Keep the car's fan running as it brings it quite a bit of fresh air. I've seen this ventilation keep the interior's CO2 levels near outdoor air levels or just above even with 2-3 people in the vehicle. Then I've used a Clean Air Kits Exhalaron in the middle of the back seat to mix/filter the air that's farther away from the vents.

Corsi-Rosenthal boxes are what they're called! I have a lot of allergies and I use one of those. They're great.

How handy are you? A Corsi-Rosenthal box is pretty easy to construct out of a box fan and 4-5 filters. Or I've seen ones that use 2 filters and some computer fans that run quieter.

Its ugly as sin and huge, but I made a CR Box and it is the best HEPA I've ever owned. They were invented during COVID to help reduce viral particles in the air but they have proven useful for any kind of indoor air quality improvement like fire smoke, dust, allergies, etc.... [https://engineering.ucdavis.edu/news/science-action-how-build-corsi-rosenthal-box](https://engineering.ucdavis.edu/news/science-action-how-build-corsi-rosenthal-box) Editing to add the other helpful thing (besides replacing furnace filters regularly) has been to increase vacuuming. I got a really great vacuum - a Miele C1 - and I've noticed much less overall dust since I got it and started a regular vacuuming rotation.