[rocqua]

From what I know, this holds for air purifiers. Quantity of air moving through matters more than quality of the filter, because of re-circulation.

The cool part of a PPS to me is that, because it is a one-shot system (no recirculation) it can actually take advantage of high quality filters.

[LTL_FTC]

Yes, sorry. By filters I meant air purifiers with HEPA filters in them. The more cycles, the better.