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(Andrew Gabriel) wrote:

In article ,
Matt writes:
"david lang" wrote:

Don't fall for the 'bagless, no reduction in suction' cobblers. True,
bagless cyclone vacs don't lose suction as they fill, but they have a
suction level so low that a nearly full bagged Numatic still has better
suction.

To eliminate the possibility of confusion on the merits of the various
cleaners could you quote the minimum pressure achieved at the nozzle
and the corresponding air flow for:

That measure is rather meaningless. The measurement accepted by
the industry is "suction power" as defined in IEC Standard 60312.

Thanks for that but "suction power" (how the hell did that get adopted
as an IEC standard!) is *precisely* why I concentrated on what to my
mind really matters, - the air volume at the nozzle and the pressure,
these taken both in the as new state and in an aged state after
passing a certain volume of air laden with a specified mass of dust.
Combine this with the maximum size of particulate at the air exit and
the mass of dust retained by the machine and you don't need anything
else to know what's better. All the parameters are measurable and
you'd only need some dust and carpet - to IEC/ISO standard of course
:-)

I use a Numatic in the workshop and a Dyson in the house but they stay
where they belong. I've found the Numatic is less than useless for
normal household use as despite having a newish bag the dust it passes
is appalling - but its fine on wood chips and swarf. The Dyson which
would quickly get knackered in the workshop is perfect in the house

"airwatts" would have James Watt turning in his grave

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