> On Jun 9, 4:36 pm, Steve Ackman SNIP-THIS.twoloonscoffee.com>
> wrote:
>

>>   At any rate, I did no calculation.  I posed a
>> hypothetical question.  

>
> (I know you're not the OP)
>
> A hypothesis without calculation is the level of science of ancient
> Greece. Very many devices you can imagine will function as a model but
> they aren't efficient. The Greeks built quite a few of them; geared
> calculators, air compressors, one or more steam engines, the coin-
> operated vending machine, complicated clocks with singing and dancing
> figures, and so on. They promoted the concept that pure hypothesis was
> superior to calculation based on measurements, possibly because they
> couldn't measure very accurately, and that held science down to their
> level until a few hundred years ago.
>
> In this case a simple rule the OP missed is that losses increase with
> the difference in temperature. Cooling water to 10C is more efficient
> than freezing it. Somewhere around -20C the heat pump's efficiency
> falls to zero.