I would suggest that you could get away with samples taken at longer
intervals. You won't lose useful information as none of the major
appliances including the air conditioner should draw a startup peak
power for over 6 seconds and what you really need is the increase in
load over a longer time. In addition, the air conditioner is a motor
load which has a lower power factor than something dominated by a heater
element.
A change between two readings at the interval you are using or an
interval of the order of 60 seconds (or longer) will essentially give
the same information -something changed in the interval- whatever it
is. Determining whatever is a bit more iffy. If you get large jumps at
2AM- blame the air conditioner. If at 8AM it could be stove and/or water
heater (breakfast and shower) indicating that you got up then.
The trouble with a whole house monitor, is that a measure of changes in
power alone, may not really give you all the data to distinguish
sources. Another is that a high sampling rate may give variations that
are really not of interest. I think that a step would be to correlate
the data with your direct observations of what went on or off - when(
i.e at the time you turned on a major load such as a stove or dryer-
both of which will cycle their power levels "on/off" in the same way
that an air-conditioner does.
(e.g. an oven will turn on until the desired temperature is reached,
then turn off , repeating this cycle to maintain a a given temperature
(+/- a bit) just as an air conditioner or dryer does).
Don Kelly
Does the meter also measure power factor or "vars"?
On 8/25/2016 8:05 PM, Joe Bogner wrote:
I posted an article that looks at some data I captured using a whole-home
energy monitor. I also posted the data. I put up a challenge for anyone
who wants to take a stab at it.
http://code.jsoftware.com/wiki/User:Joe_Bogner/EnergyUsageAnalysis
How often does the air conditioner or clothes dryer turn on?
How long does it normally run, when did it run the longest?
Is it possible to determine when I go to bed or wake up?
I'd be interested in any approaches to answering any of these questions or
other analysis on the data
For example, the air conditioner draws a significant amount of energy. I
just turned it on and my usage went from 1460-6000 watts.
Looking at the change in prior reading may be a good start
plot (}. reading - (_1 |.!.0 reading))
I have an electric dryer and electric oven.
I hope the data and article is interesting/useful
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