But I thought it has been shown putting simple furnace filter on a fan is good enough. https://www.youtube.com/watch?v=kH5APw_SLUU https://www.youtube.com/watch

But I thought it has been shown putting simple furnace filter on a fan is good enough. https://www.youtube.com/watch?v=kH5APw_SLUU https://www.youtube.com/watch?v=kH5APw_SLUU Are you talking about other filters to filter the larger particles, and carbon filters? Because aliexpress sell them too.