In article ,
NY wrote:
"Andy Burns" wrote in message
...
Even if all 220 million EU households bought a new vacuum that used
400W less than their old one and used it for 2 hours a month, it
would still be 2749.8 TWh

But *would* it still be for 2 hours a month. If you simply reduce the
motor power, without making that motor power produce more suction, all
you are doing is meaning that the device has to be left on longer to do
the same amount of work, because you have to keep going over the bits
that a stronger suction would have picked up first time.

If you followed the discussions when this reduction in maximum vacuum
cleaner power was proposed, you'd know that it *was* possible to reduce
that power consumption without effecting the amount of 'suck' by better
design. Indeed, Dyson wanted a lower limit than the one settled on.

It's the same with kettles. It takes a fixed amount of energy to boil a
given amount of water, so if you reduce the power, the kettle must be
left on longer to boil that water - no saving of energy and certainly
no saving of time (quite the reverse).

It's not the same with a kettle or many other heating devices. Near enough
100% of the energy used goes into heating the water. Unlike a vacuum
cleaner which produces noise, vibration and heat as well as suction.

Better to encourage people to heat less water - don't boil a full kettle
if your teapot only holds half a kettle-full. Or else encourage people
to use the remaining hot water as part of the washing-up water.

You can encourage people to do anything, and they can choose to ignore
you. Requiring a new device to have a certain level of efficiency removes
them being able to ignore that.

--
*Corduroy pillows are making headlines.

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