Dust collection! Cough!

[Tom]

Thanks all, really helpful.

The vax is very similar to what I've got now - it's very noisy (same as the kress), and I don't trust the filtration on it... And it needs emptying lots to keep the suction up.

Barry the one you linked to is nice and cheap, but not possible to duct outside. Like you say dust's a killer, so I'm going to steer clear of that one (unless you know any good tricks!)

The ceiling-hung filter unit sounds like a good idea. I may try making one at some point. If I built one I'd put HEPA filters on the exhaust to capture more nasties (99.99% of 0.3micron, rather than 85% of 1micron particles). I once bought filters from these guys - they know what they're doing...
http://www.aafeurope.com/en/11/products
Anyone interested in a group project in a year or so? Prefilter + Fan + HEPA filter + MDF casing = probably less than £300, and much higher airflow and filtration performance... In a previous life I helped design a cleanroom, so I recon I could spec something tidy.

On the axminster site that Fred linked to I found this extractor, which I think is my favourite. Filtration to 1micron, and the opportunity to duct the exhaust outside later (when the grand shed modification is completed). I guess it'll be a vortex type arrangement inside the bin, with the filter catching whatever's left. I like that physics does the hard work, and the filter just polishes the air up.
http://www.axminster.co.uk/axminster...tor-prod23254/

I'll do a bit more thinking, but thanks for the help...

Oh, while I was searching for particle sizes I found this paper - worth a read if you do any woodwork.