Don, thank you for the ideas. Looking closer, I see some spikes around when the A/C turns on. If I wanted to have a 1 minute interval, I still probably need the multiple readings per minute (let's say every 5 seconds) and either average them out or pick some other point. Otherwise, I might sample the peak.
I agree with correlating with known sources on/off. For example, I turned on the coffee pot this morning and saw that usage jumped almost 1000 watts. I have a routine of turning on the coffee pot in the morning so that might be easy to detect as well https://dl.dropboxusercontent.com/u/20783971/energymon_intervals.pdf The meter only measures watts. Thanks again On Fri, Aug 26, 2016 at 1:20 AM, dhkelly <[email protected]> wrote: > 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 >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
