It's obvious you don't agree with me. I'm okay with that :)
If we are talking about the Grizzly brand lower micron bags - I think I would
agree with you after reading their ads for them.
Check these out:
These replacement bags offer the greatest airflow, least differential pressure and best overall efficiency available. Micro-porous to shed dust and dirt, so bags empty quickly and completely. Envelope style.
The thing to 'notice' here is that all of these bags are the same size as their standard 30 micron bags. (One reason that the 'standard' 30 micron bags generally used on these Taiwan machines blow up and run hard as a brick is because they are horribly undersized for the application)
They honestly expect us to believe that they can increase the airflow AND trap much finer particles at the same time without changing the size of the bags at all according to both the links I posted above.
In reality it just doesn't work that way. To filter finer one is going to have to increase the bag size to make up (or reduce) for the increase in backpressure. This is why your friends were sadly disappointed.
AFF bags would have had a different result as they would have been 'properly sized' for the intended application and CFM requirements. One of the first things they did the last time I placed an order was ask about the CFM requirements for my particular machine. :smile3:
The last DC that I bought is pretty much the same thing as what (the OP) Mr. Barnett just bought. I run a @1 micron upper filter bag at the 'standard' dia. of @20" and I get relatively zero backpressure while the machine is in use. But... It takes me a good 10 feet of bag to be able to flow that much air somewhat 'freely' through that 'fine' of a filter.
8 feet worth of bag 'might' work just fine for some applications (chips instead of fine dust for example) but the bag is definitely going to want to puff up a lot firmer than a 10 foot bag.
I can't imagine for the life of me how it would be possible to NOT choke down a machine with backpressure if a guy was trying to push that much air through a bag type filter designed to only allow relatively small particles to pass through at only 3 feet of length.
That just ain't going to happen. .