AirPura is one of the good ones: https://www.airpura.com/ https://www.airpura.com/ I have one and it felt nice, unfortunately because people smoke in the build

AirPura is one of the good ones: https://www.airpura.com/ https://www.airpura.com/ I have one and it felt nice, unfortunately because people smoke in the building I live I can't use it since the smell collects in the filter very quickly and they are expensive (but last a long time if not for the smell). A bunch of carbon could help with that but a) I try to avoid stuff from low wage countries as the carbon is (but not the rest of that particular air purifier as far as I could tell) and b) hopefully I can just move in the not extremely distant future. There are a few others as well, look for the better quality filters ("SuperHEPA" as AirPura calls them). As I understand it, the small particles are the ones that aggrivate allergies the most and that is exactly what the higher quality filters are better at. Only a relatively few companies have those better filters, IQAir is another one. It turns out the name HEPA doesn't mean anything for consumer filters, you need to look at the specs.