Since we were talking about Costco

[geoff]

I was in the local depot today and walked past a demonstrator and heard her say ...

"...it cooks in half the time, so OBVIOUSLY it uses less energy "

[Toby]

Maybe it does, like a 3KW kettle uses less energy than a 1.5KW kettle to boil the same amount of water?

Toby...

[geoff]

In message , Toby writes

Well - "maybe", but not "obviously"

[Harry Bloomfield]

Toby has brought this to us :

A 3kw kettle does use very slightly less energy - it boils it up quicker, therefore there is less time for the heat contained within the kettle to be radiated out to the surrounding air.

[The Natural Philosopher]

On the other hand the higher currents heat up the wires more..;-)

[Harry Bloomfield]

.but for less time :-)

[Toby]

I know!

[David WE Roberts]

I drove there twice as quickly so OBVIOUSLY I used less petrol??

[The Natural Philosopher]

Which might, or might not, be true.

Sadly these things are very much NOT obvious.

Even more sadly, precocious gits who have ticked more than half te boxes right in a multiple choice O level physics paper, now think that 'know about physics' well enough to make comments like that.

[Archie]

Pressure cooker?

[geoff]

In message , Archie writes

Some sort of radiant ceramic cooker

looked like a fish bowl with the heater on top

[Ericp]

A JML halogen oven.

[Andrew Gabriel]

I saw those too. I'll bet it's an absolute delight to clean, not.

[Wesley]

We've been using an Elitech halogen oven for almost two years now and they

*are* a lot quicker and cook at a lower temperature than an ordinary oven so they may, in fact, be cheaper to run.