On 23/04/2017 21:31, The Natural Philosopher wrote:
Of course being bagless the filters clog up with fine dust in weeks.

Then they stop working.

Not in our experience.

OTOH the little filter based one I have for the workshop - I got it on
freecycle, and it's never been much good. I got fed up the other day,
and took a knife to the filter. It's transformed. But doubtless not
HEPA... I wore a dustmask while I was using it where the floorboards
used to be.

Andy