Saturday, August 20, 2016

alternatives

INDEX to the series

I have been learning about my home electrical usage through my smart meter data and finding it not so smart without some added software. Nevertheless, I have been making use of all this new data and making improvements (reducing the variable portion of my electric bill) while making plans for next steps some of which involve more measurements.

Adding the timers to the water heater, fridge and freezer to move them off my peak rate times was an obvious move but a bit bothersome. The timers don't always work. I had trouble with a wireless type so went with plug in autonomous timers. The cheap Chinese ones I bought on Ebay for $10 each sometimes do not switch as they are supposed to. I went electronic but it would be simpler just to have mechanical timers and cheaper. Try to find three prong versions (properly grounded). The timer for the water heater had to be wired in.

I have been thinking about remote controlled AC sockets. Particularly interested if they monitored the load as well as controlled it, something like the Belkin WeMo.

What if these devices mounted directly in my electrical panel as snap in replacement approved devices that communicate wirelessly? That doesn't exist yet. Maybe with the Internet of Things (IoT)?

Controlling my appliances could be done currently through some type of home automation system, via software, in a browser. That would be nice. I am looking around for suitable systems.

About the monitoring, I still don't have appliance level data from my smart meter or any meaningful breakdown. There are software tools (some of which have their own hardware and sensors) like Plotwatt, Bidgely, Navetas, eyedro and Neurio.

Some, like Plotwatt, are being marketed to the utilities as a service they would provide, whether added to my bill or not, is playing out now in the market. I am looking at my account on-line at Hydro One Networks and I can see many tools to help me understand my electrical usable but no GreenButton links as yet or any appliance level information, just general.

There are systems marketed for the DIY types like TED (The Energy Detective) and OpenEnergyMonitor.

But using my smartmeter is not the only way to understand my house electrical and to monitor my appliances. It might not even be the best or only way. It will probably be some combination of tools that will guide me to what I need to know.

Different tools work different ways. Some plug in between my appliance and the wall. Others involve the installation of a small sensor in my electrical panel.

Of the plug in kind, the Kill A Watt has been popular for a number of years. It measures the energy used at the outlet and stores some totals like kWh per day, week, month, year since plugged in and if you enter rates, it will give you a cost. It does not connect to anything so you can't get the data out of it and when you unplug it resets. Not very useful with tiered rates but the kWh measures could be useful. It is limited to regular plug in 120 VAC appliances up to 1500 watts so you can't use it for a water heater, clothes dryer or airconditioner or a furnace, in fact any of your larger appliances. But still a useful tool. I have had one for years. It does not measure low power very accurately, like below 10 watts.

These and other types of plug in meters may be available at your library http://georgesworkshop.blogspot.ca/2014/12/your-library-has-tools.html

Understanding home electrical use is part of the broad category of Noninvasive Load Monitoring (NILM). Here is good background at Wikipedia https://en.wikipedia.org/wiki/Nonintrusive_load_monitoring

Some interesting academic links:

https://web.eecs.umich.edu/~prabal/pubs/papers/campbell14gemini.pdf

http://www.ucl.ac.uk/carb/pubdocs/CP-DMU-09-IEECB08-NoninvasiveMonitoring-2008-NRB-AJW.pdf

http://digitalassets.lib.berkeley.edu/techreports/ucb/text/EECS-2012-152.pdf

Thanks for your interest.

George Plhak
Lion's Head, Ontario, Canada

INDEX to the series

Friday, August 19, 2016

heat

INDEX to the series

I hope the basement will be warmer this year because I have rebuilt the two basement windows in the house. There had been significant cold air coming in from the outside before this repair.

I am also planning to cut off heat to the sun room. It has a lot of big windows. A wonderful room in the summer. A wonderful room in the winter also but it must cost me a lot to heat it. I don't know how much but I would not be surprised if heating the sun room was 1/4 of my heat cost including fuel and electricity. Calling it a sun room in February here in Lion's Head is a gross misnomer. There is not much sun here in February.

I have replaced the operable sun room windows with nice thermopane but the large ones are single panes. This room has a bad air leak noticeable when the wind blows a certain direction and the door to the outside does not seal very well at the bottom.

So this winter, I plan to temporarily partition the sun room, including the forced air duct that feeds heated air to to its three floor vents. That duct is large (16x8 inches) and has no damper (air control valve) in it now. I would like to add one. A quicker fix is to block the three floor vents. There is no return air duct. Return air just flows back into the main house through a six foot wide open doorway.

I am not going to heat that room this winter. I will modify my behavior by doing without a whole room for the winter except for cold storage. I don't use the front door although I keep the snow clear from the door as an emergency exit so the partition will need to have a door.

Conservation is key to reducing my electrical usage. If I need less heat, I will use less electricity even though I use oil primarily. In my furnace, there are two hungry AC motors and the ignition which run while the furnace runs. I have not seen it on the smart meter yet. I'll be firing it up for a test run in the next few days.

I had installed a programmable thermostat a couple of years ago. My strategy was to go between two heat levels. One as low as I could stand for night (about 13C) and another for the daytime (about 18C). Thinking about my huge rate differential in the study leads me to a different strategy. Should I minimize during the peak times by keeping the same temperature (low) all day while creating a warmer room in the house (the work area or the sleep area) with a local portable electric heater?

With better insulation in the basement, no heat in the front room, it might even be possible for me to ride out the six hours of peak without running the heat? Like I do with the water heater, the fridge and the freezer. If that were possible, I could then have the night time temperature whatever I wanted, at least in electricity terms.

I have become quite interested in the technique of the Moody wall which I could use upstairs?

Thanks for your interest

George Plhak
Lion's Head, Ontario, Canada

INDEX to the series


Tuesday, August 16, 2016

insulated refrigerator freezer 2

INDEX to the series

Another chart from last night on the superinsulated refrigerator freezer.

I want to know, using my smart meter data, if the refrigerator's standby energy use is any different (hopefully less) with the "blanket" of insulation I added to the freezer compartment. My previous test was inconclusive because the ambient temperature was different from the one measurement I made before I added the blanket. I wish now I had taken more measurements.

The standby electrical usage of a thermal box type applicance, like a refrigerator, a freezer or even a hot water heater varies mainly with the temperature of the air around it (the ambient temperature) and the insulation.

In order for me to make a meaningful comparison, all things (controllable variables) should be kept the same. The ambient temperature is not really a controllable variable but it is from an experimental point of view.

So I am taking snapshots of my smart meter data and reading each manually. I see a graph of my usage at any time and I can pick out the appliance. I can measure it very accurately. But with the software I have now, I cannot tabulate or totalize usage by appliance over say a month or a year. So I am estimating to get an idea for ranking, highest to lowest. I am also learning a lot about how my appliances behave as electrical loads and explaining as I go (the INDEX). I can "see" my electricity use with my smart meter data, but just how useful is it?

(click any pic to enlarge) I should compare measurements at the same ambient temperature. I could make a graph of standby usage with temperature for each of these type of electrical loads. If I took a number of readings at different temperatures, I would be able to plot how the appliance usage varies with ambient temperature. Better efficiency would tilt the slope of the line. Better thermal boxes would not vary as much with ambient temperature. It is really ALL ABOUT INSULATION for thermal boxes. The more the better.

The nights here are still pretty warm. About the same as for the previous test 20C so this will qualify as a repeat for comparison. And to shake down the method. There were a few mistakes this time also.

Not as careful as I should have been, I see this morning that I left the Exterior Moisture Control ON last night. This switch activates a heater in the door gasket. I want that OFF! I had thought I left it OFF. I am going to put a piece of tape over the switch so that it stays OFF.

One thing I notice about the chart is that the fridge seems to be coming ON for shorter periods each time across the chart. I remember that my bedtime snack was a small dish of ice cream, so I had opened the freezer door about an hour before the chart. Its possible that the fridge was still recovering. I should make sure next time that the fridge has not been opened for at least several hours before the measurement.

The chart covers from about 22:30 to 01:30. The width of the peaks are 0.92cm, 0.80, 0.76 then 0.72. I am using cm as an analog for time. Time on the chart I measure to be 1.92cm = 1 hour.

The peaks also seem to drop down slightly, the first two are higher than the last two. I see that the base load drops about 25 watts at about midnight. I am not sure what turned OFF in the house. I was asleep. This is my whole house electrical usage so the fridge is riding on top of the base load.

Let's do some calculations anyway.

Here is the same chart in CorelDraw with the measurements added.

For the first two peaks, the fridge is using (275-125=) 150 watts and for the last two (250-100= 150 watts so the instantaneous power is the same as the last tests.

For the first peak, run time is 0.92 and cycle time is 1.84 so the duty cycle is (0.92/1.84=) 0.5. The second is (0.80/1.69=) 0.47. The third (0.76/1.65=) 0.46. I cannot calculate the fourth since I don't see the complete cycle. Doing the same calculation as before (power x time x duty cycle) I calculate for the three peaks 1.8, 1.69 and 1.66 kWh per day or 1088, 617 and 604 kWh per year. Quite a wide spread and more usage than before.

I know the insulation does not make the refrigerator use MORE power. Something about my measurement or the method is not right. And there was that dish of ice cream.

There must be an easier way to do this. I should let a computer monitor my energy use!

I am not discouraged.

Thanks for your interest

George Plhak
Lion's Head, Ontario, Canada

Update - The metal frame of the fridge where it touches the door gaskets is now covered with dew (condensation) so I see that the switch for Exterior Moisture Control really is activating heaters in the door frame. The dew isn't usually there. I wonder how much energy that takes and when the heaters come on? I think I remember reading that the heaters are activated by a time delay relay in the fridge that starts when the door is opened using the same switch that turns on the fridge light.

INDEX to the series