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

"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

The high-low settings are only for the fan, not the compressor so any
difference is very minimal. The compressor is either on or off and takes
the same power no matter what the fan setting is. To cool the room down,
you have to remove a certain amount of heat and will have a pretty fixed
cost per thousand Btu's removed.

Run the fan to what seems best for the room and noise level you can
tolerate. High circulates more air so the more distant parts of the room may
feel a little cooler faster, low is usually best for sleeping as long as the
cool air is reaching you.

"Ed Pawlowski" wrote in message
...

The high-low settings are only for the fan, not the compressor so any
difference is very minimal. The compressor is either on or off and takes
the same power no matter what the fan setting is. To cool the room down,
you have to remove a certain amount of heat and will have a pretty fixed
cost per thousand Btu's removed.

Run the fan to what seems best for the room and noise level you can
tolerate. High circulates more air so the more distant parts of the room
may feel a little cooler faster, low is usually best for sleeping as long
as the cool air is reaching you.

It would seem that for pre-cooling, a high fan speed would be better. The
hot air in the far reaches of the room would reach the return intake sooner.
Then slow it down after it's comfy. Not disagreeing, just wondering.

"1D10T" wrote in message

It would seem that for pre-cooling, a high fan speed would be better. The
hot air in the far reaches of the room would reach the return intake
sooner. Then slow it down after it's comfy. Not disagreeing, just
wondering.

It would make the room feel cooler all over faster for the reason you state.
Depends on how long you pre-cool and how hot it is starting out. The system
can only take away so much heat at a time so that is the overall answer for
total comfort.

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.

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

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

With the high fan setting, the cold air is "thrown" farther
into the room. Low fan, the AC sits in a small puddle of
cold, near the unit. Which is why I also reccomend the fan
pointing toward the AC, so that the AC can do its work,
cooling the room.

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


wrote in message
...

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.