Wouter,

On Mon, 25 Sep 2006 15:05:29 +0200, Wouter van Ooijen wrote:

>...
> Anyone got experience with DIY cental vacuum. Will an old vacuum cleaner
> with adjustable power do, for 1. solder fumes 2. drill/saw dust? I would
> guess OK for 1 but early death of the motor for 2.

There are a number of factors:

 - Rating of the motor - most domestic equipment isn't designed for 16 hour workdays...
 - Cooling - make sure there is airflow through the thing at all times (have a "leak" built into the system if you think this is an issue)
 - Overfilling collection chamber and clogging of filters

For the latter you can have a pre-collector / filter - I built one using "cyclone" principles, using a 20litre plastic drum with a removeable lid.  Mount 
the outlet to the vacuum cleaner in the centre of the lid, protruding slightly into the drum.  Mount the inlet from the bench pipework at one side, and 
have a pipe inside that goes nearly to the bottom and then turns 90 degrees , and exits round the circumference of the drum.  This sets up circulation 
of the air, and causes particles to centrifuge outwards and drop to the bottom of the drum, and relatively clean air to leave through the centre of the 
vortex.  This works well with wood shavings, sawdust and swarf, and large particles of dust - fine dust still gets through, so you could incorporate a 
filter over the exit pipe to deal with this.  I didn't, since my vacuum cleaner has HEPA filtering anyway and I don't create a lot of fine dust (I hate 
sanding! :-)

Of course for fume-collecting there are other issues: Noise (can you install the vacuum cleaner outside the workshop?) and the fumes themselves - 
you really need to filter them using an activated-charcoal filter, not just blow them into someone else's space!  :-)  This filter needs to be at the inlet 
end, obviously, so it's not in the path of anything collected by function 2.

Cheers,


Howard Winter
St.Albans, England


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