phil scott wrote:

Best move imo for perfomance and pressure drop is to buy a 2" thick
Pleated filter... thats about 4x the surface are aof most other
options and these are inherently more efficient on the same size
particles...about 30% efficient clean.... pressure drops in the range
of .25" or less water column dirty at 500 fpm face velocity..

For near zero pressure drop though, you can go to a pure electronic
filter, wires and plates. with oversized 15% prefilters (set in on a V
pattern for a 200 fpm face velocity...

Envirosept is an in-between 2-watt 7 kV charged media filter with good
particulate performance and a 0.1" H20 drop at 225 lfm.

Nick