@cleanairstars Awesome! It's encouraging to see such a slim profile performing. I'd been curious about the size of air gap.
@WilliamRamsey it may need more than 1cm, @DavidElfstrom may be able to suggest a more optimal distance for the gap, but any is better than none just to give the air access to otherwise covered filter surface at the corners of the fan housing
@cleanairstars @DavidElfstrom Another question I have is, through all of these tested diy designs, do we have a general idea of effective filter surface area per fan, such that, for a specified fan and filter, similar performance can be achieved with 4", 2", and 1" deep filters by altering width/height to equalize surface area?
@WilliamRamsey this is what a 2x2 Arctic P14 with a 1cm spacer against a Kmart Anko EPA11 filter looks like sitting on a desk. Very quiet. A PM reduction over distance was measured for the same filter with a 2x3 configuration demonstrating ~ 90% reduction at 50cm, ~75% at 1m.