Your opinion of "what they should be" and what the individual wants is
totally irrelevant. If one wants the temperature either higher or
lower than someone else that's nobody's business but the one who pays
the bill. We don't have any Temperature Police... yet.
On Wed, 08 Aug 2012 16:50:19 -0400, " firstname.lastname@example.org"
They are trying to reduce PEAK load. Lets say there are 1,000,000
power customers. And lets say they want to reduce the peak load 10%.
If all those users AC units were running then turning off 10% of the
running AC units would get MORE then a 10% reduction in peak load
because the AC while running is probably 50% of the load on each
house. So they only need to turn off perhaps 5% of the AC units at any
one time. If the meters are really "smart" they would be able to tell
if the AC is on or not if by no other way then simply the current draw
at that point in time compared to the average for a typical day in the
season. So they should be able to target running ac units. And since
it's "smart" they should be able to shut down *just the right number*
of them to reduce the peak load to whatever their target is. Going
back to it probably being 5% or less needing to be turned off at any
one time, that means of the 1 million houses, if they cycle thru each
house so no house gets hit twice until all the houses with running ac
have had a turn, it means they need to turn off 5% of a million, or
50,000 AC's. If they want to keep the off time to 10 minutes (1/6 of
an hour), it means that for every hour they want to reduce the peak
they need to deal with 300,000 AC's. Given that they have a million
of them, and on a really hot day most of them will be running at any
point in time, that means they have a 3+ hour time period where they
can be turning off AC units without ever hitting the same house twice.
Rounding up to make this example worse, lets say I'm off by a factor
of two, it still means that at most your AC will be turned off for 10
minutes twice in a 3 hour period and the off time would be 1.5 hours
apart. I doubt many people would ever notice those two-10 minute off
periods 1.5 hours apart. And for those rare people who do notice it,
by the time they notice it more then likely the 10 minutes will be
expired and it will be back on.
I just went thru this on the fly so I could have missed something but
assuming it's a reasonably good armchair estimate, the use of smart
meters to control peak use seems like a very good way to save money
(by not building excess capacity to deal with a couple hours of peak
use) with essentially zero impact on anyone's comfort and convenience.
While a quick read of this seems to make sense, the one statement I might
have an issue with is this:
"And since it's "smart" they should be able to shut down *just the right
number* of them to reduce the peak load to whatever their target is."
If you are talking about the meters, I don't think that they are smart
enough to know what's going on across the grid. Some other system would
have to tell the meters which AC units to shut down and for how long.
I think. ;-)
(You really need to breathe once in a while)
The problem with your theory is that it doesn't work. The peak power is
exactly the same (as is the average) unless they're leaving the power off long
enough for it to get warmer in the house. Then the difference is only in the
Doesn't work. A soon as you turn the block of ACs back on, *every* one will
cycle on, increasing your peak. You've actually made it worse because they're
all synchronized, now, rather than random.
On Mon, 13 Aug 2012 18:14:30 -0400, " email@example.com"
Off course it does, otherwise why wouldn't you simply put a timer on
your AC to turn it off 10 minutes out of every run hour just to save
money. You're not seeing the small picture at the house end nor the
big picture at the system end.
Ok, you've just proved my point. If load shedding worked on air conditioners,
everyone would just power them off for 10 minutes per hour and save on their
power bills. The fact is that it doesn't work. Worse, it synchronizes the
BTW, did it really take you two weeks to read my post?
On Sun, 12 Aug 2012 22:44:47 -0400, " firstname.lastname@example.org"
No kidding. I wrote that a few days ago and just came back to the
thread. Wow, almost like a drug induced dream.
I think you miss the whole point of the system. It *IS* going to
reduce the peak because that's the driver determining whether to turn
off *any* houses. If the algorithm says "we're peaking according to
the powermeter" it starts to turn off AC units and continues to do so
until the algorithm says "you've turned off enough and the power
output meter is now back down where we want it". It will continue to
iterate that cycle till it starts to drop off the peak and then it
turns AC's back on. Of course it's not going to pick YOUR system and
keep it off for 3 hours, it's going to spread the *off* time over the
millions of houses, 10 minutes at a time. And yes, the houses turned
off will each get a tiny bit hotter, ... if that were not the case
their AC would not have been needed.
Doesn't matter, the algorithm will have taken that into account and
each time one it turned back on, another house somewhere else gets
turned off unless the "master power meter" says it's started dropping
off the peak. Not only will another house get turned off as a
replacement for the one that was just turned back on but if the system
is still "peaking" an additional house will get turned off. That's
the beauty of this kind of system, it's able to spread the pain out
over such a large number of houses, for so short a time at each
individual house, that no one house even notices the 0.3 degree rise
in temperature for that one hour slot.
No, I didn't miss anything. The system doesn't work unless they're going to
shed loads long enough for the *average* temperatures to get significantly
higher. Ten minutes isn't going to do anything except synchronize the load
(the worst possible outcome).
Then you've done exactly nothing. The house you're just turning back on
*will* come on. It's duty will not have changed. Its total power will not
have changed, except for the 10-minute lag.
Maybe all the cumulative inrush current happening randomly is part of
the problem. If they shut off compressors in whole neighborhoods, they
stand to route it elsewhere. Then just rotate the "rolling AC blackout"
around the city at different times.
On 08/08/2012 11:39 AM, email@example.com wrote:
If you have to run your AC 100% of the time to be comfortable, you have
an incorrectly sized AC. Doesn't the power company take this into
consideration when they decide if you are eligible for the discount?
Or, the AC you have is running far less
Have it serviced.
Christopher A. Young
Learn more about Jesus
If you have to run your AC 100% of the
time to be comfortable, you have an
incorrectly sized AC. Doesn't the power
company take this into consideration
when they decide if you are eligible for
On Wed, 15 Aug 2012 17:58:28 -0400, "Stormin Mormon"
Actually, for maximum efficiency and maximum dehumidifying, an air
conditioner that has to run constantly on the hottest anticipated day
to maintain the desired temperature is sized "just about right".
Mine is too big - just like my furnace - and runs about 8 hours a day
when outside temps hover in the low 90s F - which is as hot as it
usually gets around here. Running only roughly 30% of the time,
humidity is not as well controlled as it should be - an additional
dehumidifier extracts about a gallon or more a day with outside
humidity in the 73% range - which is on the low side of normal for a
sothwestern ontario hot summer day.
On Wed, 15 Aug 2012 19:28:25 -0400, firstname.lastname@example.org wrote:
Some decades ago, my father was the maintenance supervisor for a
printing plant. The plant was air conditioned to provide for better
handling of paper and printing. To control the humidity on damp
cooler days, they would run the heat at the same time as the AC.
I don't know the capacity of the AC, but I remember walking into the
ducts where the filter system was. .
The air conditioning for data centers where something like a super
computer is operated on a raised floor has air handlers which blow
air down under the raised floor so cooling air can come up through
open sections under equipment to cool it. The air handlers often have
pans of water with electric heaters to add humidity to the air and
will control humidity using a method called reheat which will reheat
the cooled dehumidified air the bring it back up to room temperature. ^_^
On Wed, 15 Aug 2012 22:58:34 -0500, The Daring Dufas
Are any "supercomputers" air-cooled? The ones I've worked with were water-
cooled, with heat exchangers under the covers for those parts that use air.
Only peripherals, smaller computers, and test equipment used air from the
floor as the cooling source.
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