I think you guys have hit on something with the inlet speed. The Clearvue was designed specifically for 6" mains with an inlet velocity in the 5-6000 fpm range. The 55-60 sq inch inlet on the Torit is likely to reduce the speed to the same range when running with 8". The working range of my unit is between 1200-1600 cfm . Higher is possible but not with a 5 hp motor so to hit the higher numbers the system would need the 7.5 hp motor and then Torit moves to a 24" cyclone to again slow the speed down. As to the filters, I built my own plenum but if it worked out I would use the one supplied by Torit and replace two of the four tubes with cartridges and run a combination of both. The 100 sq ft that Torit comes with works much better if expanded and filtration is improved when the air isn't forced through. I run one 100 sq ft cartridge and four tubes equalling another 100 sq ft on mine and am considering replacing one of the tubes with another cartridge. My cartridge is spun bond rather than hepa but the Dylos stays so low I don't know what I would really gain with the Hepa and of couse I would have to change them all or it wouldn't make sense. Dave