3 ms·
PM2.5 is around the hardest size to filter, I don't understand the physics but both larger and smaller are actually easier to remove from the air. Given that 2.
by hedgehog 2y ago
PM2.5 is around the hardest size to filter, I don't understand the physics but both larger and smaller are actually easier to remove from the air. Given that 2.5 is a useful estimate of worst case performance for a given setup.
- TylerE 2y agoBasically a HEPA/electrostatic filter works in two ways. As a “physical” filter (think fishing net), works well on big particles. As an electrostatic filter, works best with really small, works by electrically attracting particles and having them stick. 2.5 micron is in the middle crossover range where total net effectiveness is worst. Respirators are rated at the same size for the same reason.