On Wed, 2007-01-17 at 09:10 +0800, Richard Prosser wrote:
> > The most efficient device you have would be your electric kettle.  Its sole
> > purpose in life is to turn electricity into heat, and it does that very
> > well.  It would be 100% efficient except you lose a little bit in the cable,
> > but never mind.  Plonk a Stirling engine on top to capture the waste heat,
> > it can power your coffee grinder.
> >
> > Tony
> >
>  Not quite true. A heat pump can run up to about 300% efficient in heating mode.

I was always "bugged" by those efficiency numbers! :) Just something
about 300% efficiency...

My parents have some split AC units in their house that can reverse to
heat pump mode in the winter. When the weather is mild enough to use
them (above say -5C) they work VERY well and actually end up saving him
quite a bit of money on heating (since he just heats the rooms he's in).

Funny thing is when he was buying them the "heat pump" feature wasn't
very important to us, we were getting them for cooling. But now when I
ask him he mentions he's almost never used them in cooling mode, but
they sure have used them alot in heating mode! :)

It's a shame they basically stop working below a certain temp, I'd love
to have a heat pump in my house for heating, the cost savings would be
quite nice.

TTYL

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