On Jun 9, 9:03*am, "Stormin Mormon"
wrote:
The compressor is the big energy draw. High fan does take
more energy per hour, or per minute. But, the AC spends less
time with the compressor on. The high fan setting is most
efficient.

I'm not so sure that it's true that the compressor stays on for a
shorter time with the unit on high, at least from first order, direct
effects. As Ed pointed out, the compressor only has one speed, at
least in the units I've seen so far. Which means it pretty much has
to run the same amount of time in either case, to move X amount of
heat and get the temp down to the desired level. If you have the
fan on low, the compressor will start to cycle at some point, so while
it will take longer to reach the target temperature, the compressor
isn't necessarily running all the time.

If you factor in the second order effects, meaning that on low it will
take longer to get the room to the desired temp and that during that
longer time, more heat will be entering the room, whcih then also
needs to be removed, then I can see where running it on low will take
more compressor run time and energy.

I would think that from an energy usage standpoint, the whole thing is
probably so close it doesn't make much difference. Hence, I'd go
with the high speed, so it gets cool faster.





Also, a fan blowing towards the AC helps cool the room,
faster. If you put a fan blowing away from the AC, it dosn't
seem to help any where near as much.

--
Christopher A. Young
Learn more about Jesus
*www.lds.org
.

"Pavel314" wrote in message

...
I turned on the through-the-window air conditioner in the
bedroom to
cool it down earlier and wondered which setting, high or
low, would be
more energy efficient in pre-cooling a room. It seems that
setting it
on high would cool the room quicker then cycle on and off to
keep it
at the desired temperature. However, the high setting does
use more
energy when it's on, I believe, so maybe putting it on low
and
allowing a slow, gradual cool-down would be better. Or maybe
it
doesn't make any difference. Does anyone have any ideas
about this?

Paul