In article ,
Arfa Daily wrote:
Why should they 'strive'? They're not paying for the electricity. But
they are for the motor, so the cheaper, the better.



Because these days, it's seen as expedient for manufacturers to be seen
to be trying to wring every drop of efficiency from their products. You
could use the same argument to ask why the makers of TV sets or fridges
or washing machines or a myriad of other consumer electrical items
would bother to try to make their products more efficient, but they
have ...

Because, like you, many don't consider the power consumption of a vacuum
cleaner important. Because it's not used for long periods. Not that it
stops them fitting low energy lamps to the broom cupboard, though.
And, of course, many will relate the wattage of the motor to the
performance. The very worst vacuum I've tried is a Lidl with a 2000 watt
motor. An attempt to produce a small(ish) bag less type. My most powerful
one? An ancient Rowenta wet or dry with a 900 watt motor.


I'm not convinced the speed the average vacuum cleaner motor/fan runs
at is ideal. More likely just convenient.


Convenient how ? They can design the fan any way that they want and
make the motor run at any speed they want.

Can they? A universal motor is intrinsically high speed. So it's perfectly
possible this compromises the design of the fan. Fitting a gearbox would
add to the cost.

Do you seriously believe
that they would just pick some arbitrary combination and declare
"that'll do then ... " ?

In many cases, yes. Which is why the performance of such things varies so
much. My guess is you've not got much experience of Hoovering. ;-) Some
have the most appalling design gaffs. Like the upright types where you can
remove the hose from the 'beater' box to use say on the stairs. And as
soon as you pull on it the whole lot tips over. Designed by an idiot who
has never used one.


They certainly make enough noise
and get hot.

And that's important because ?

Both heat and noise waste energy. Especially heat.

--
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Dave Plowman London SW
To e-mail, change noise into sound.