Documenting my attempt to cut my energy usage in half.

Tuesday, March 22, 2011

HP PSC 2510

While I was surveying the house with a Fluke thermal imaging camera the other day I happened to take a look at my HP PSC 2510 all-in-one printer/fax thingy.

I sure wasn't expecting it to be using electricity as I usually keep it turned off since it's really only used maybe once a month.  When this picture was taken the printer had been off for over a week.  Interested in how much energy it was actually using, I plugged it into a Kill-A-Watt meter.

  • On (idle) - 18 watts
  • Off (or so I thought) - 10 watts
So, 10 watts for an entire year equals 87.6 kwh, or about $10 a year to sit there... off.   For the thousands of these that sit around "on" all day/night, it's about 157 kwh/year ($17). 

Sunday, March 13, 2011

My Half Project - Thermal Imaging

The other day I undertook an effort to scan the entire house with a Fluke Ti32 thermal imaging camera.  The good news... no bad news.  I didn't find any major issues.  I had hoped to run these scans when there was a large difference between inside/outside temps so that any issues would be more apparent, but the day I could get the camera the outside temperature was about 15 degress below the inside temp.  I have arranged to get the camera again during the summer.

The Fluke software is really nice in that it allows for a lot of post processing of images.  I really like that you can overlay the thermal image on the visible light image so it's easy to see where the picture was taken.

This is the backdoor leading into the garage.   The bottom seal could use a little work.  It's very obvious where the cat plucks at the seal in the lower left corner.

I was surprised to see how the windows looked.  This is a window on the north side of the house at 10am.  Outside temp was around 50.  All of the heat loss appears to be right around the edge of the window.  All of the windows had this same look.

The insulation on the water heater appears to be good.  Tank temp is kept at 120 and most of the outside of the tank is around 68.  The base is around 80 and it appears that the connection between the tank and the geothermal heatpump could use a little more insulation.

Looking straight up at the roof ridge.  Can you guess which is the south facing roof?   Outside air temp was 50, attic temp was 55.

Next step is to fix the few minor issues that I found.

Thursday, March 10, 2011

TED 5000 Load Profiling

The HA software has been logging "seconds" data from the TED for a couple of days and I've started to do a little bit of post processing on the data.  For the most part detecting when the hot water heater kicks on is easy.  Below is a snapshot of data that I'm pulling down from the TED and saving.  The log has date/time and usage in watts.

03/05/2011 14:34:21, 1362
03/05/2011 14:34:22, 1362 
03/05/2011 14:34:23, 1362  
03/05/2011 14:34:24, 6897  <-- DHW ON.    Load change of ~ 5500 watts
03/05/2011 14:34:25, 6897

This is easy to parse and detect that the water heater came on.  But it's not always this simple to detect.  Yesterday the water heater came on over a few seconds...

03/09/2011 00:49:59, 2796
03/09/2011 00:50:00, 2796
03/09/2011 00:50:01, 4109  <-- started
03/09/2011 00:50:02, 4109
03/09/2011 00:50:03, 4109
03/09/2011 00:50:04, 4109
03/09/2011 00:50:05, 4109
03/09/2011 00:50:06, 8104  <-- full load

And later in the day it came on while the heat pump decided to turn off.  This is a more difficult situation to detect as I have no data to indicate a load change of ~5000 watts.  Best I can do is detect the off event and back track and try to guess where the on event occurred.

03/09/2011 07:13:53, 2694
03/09/2011 07:13:54, 5697
03/09/2011 07:13:55, 5697
03/09/2011 07:13:56, 5697
03/09/2011 07:13:57, 5697
03/09/2011 07:13:58, 5697
03/09/2011 07:13:59, 6153  <-- DHW ON, heat pump is shutting off.

I can set up the HA software to detect most of these different "on" events because I know what's on each panel and I know that there isn't another load like the water heater on panel 2.   These multi-second on events is why I think that the load profile software within the TED has difficulties and sometimes misses either the on or off event.  The profile that it learned was for 5500 watts almost instantly and for most cases this is how the water heater comes on.   If the device doesn't come on like that every time, then the TED is going to have issues detecting it.

Detecting multistage loads while dealing with other loads going on/off will be challenging.

Tuesday, March 8, 2011

TED 5000 Load Profiling

I finally got the load profiling data for my hot water heater that I could not obtain directly from the TED.   I went through a couple of iterations of retrieving data from the TED before deciding on a workable method.  I tried retrieving the historical minute data but that didn't give the resolution that I wanted.  So I switched to retrieving the historical second data.  It's a lot of data and the TED is really slow at delivering the data via XML.  I found in the API where I can get the raw second data and this downloads much faster.  The TED gateway only stores about an hour of second data so I have my HA software downloading the second data every 30 minutes and saving it off to disk for later processing.  This will be a workable solution.

The graph above is from the first full day of pulling second data from the TED.  It was a very low usage day for DHW which is what I wanted so that I could get a feel for how often the water heater comes on and for how long.  Total run time for the hot water heater for 3/6/11 was 83.95 min @ 5500 watts for a total of 7.7 KWH.  Almost all of this is the heater coming on just to keep the tank hot.

Saturday, March 5, 2011

My Half Project - Window Shades

34... I thought the answer was supposed to be 42, but 34 seems to be the number of shades that have been installed on the south facing windows.   The shades do not cover the transom windows so a lot of light will still be able to enter all of the downstairs rooms.  I also didn't install shades on windows that are mostly in the shade of the upstairs deck.   I'll start closing these when it gets warm enough for the AC to kick on.  I'm interested in what affect these will have on the hot summer months.

Thursday, March 3, 2011

TED 5000 Load Profiling

The Load Profiling still isn't working like a want.  As I mentioned in a prior post, the TED is missing some of the on/off events for the water heater.  While waiting to do the firmware update last night, I saw on the graphing tab that the water heater turned off in two seperate events.  I'm guessing that both elements were on and turned off about 3 seconds apart.  This was enough for the TED to miss the profile event.  Ugh.  The current plan now is to change the load profiling code that I put in the HA software yesterday so that instead of pulling down load profile data that the TED has collected, I'm going to pull down the historical minute data and parse that to find the water heater events.

The advantage to this is that the HA software can have more intelligence built into it since I know what loads I'm looking for and can set it up to handle events that occur over a period of time.  I will lose some resolution by looking at the minute data instead of the seconds data, but I think that will be ok.  One other note about the minute data is that the TED seems to only keep about 48 hours worth.  I'll have to set the retrieval of this on a polling timer and save the parsed xml out to disk for later processing.

TED 5000 Load Profiling

I had some success and some failures with the TED 5000 today.  First the good news... I made the changes to my HA software to query the TED for the historical load profile data.  This works well as it's now set up to pull data every 4 hours and I can also force a query as well.  The xml data is parsed and written out to disk making sure that there are no duplicate entries.

Now for the bad.... Failure #1, after I parsed the historical load data from the TED I noticed that it didn't always detect the water heater turning off.  When the next "on" event happens it won't log that either since it thinks the heater is already on.  If the heater comes on for 5 min, goes off for an hour, then comes on for 5 min, I will occasionally get xml data returned that says that the device was on for 1 hour 10 min.  It doesn't happen frequently, maybe once or twice a day.

Failure #2, I upgraded the TED gateway firmware from 1.0.400 -> 1.0.406 and the Footprints from 1.0.222 -> 1.0.223.  Checked the load profile tab and it still says I have no data.  Which is odd since I can query the XML directly and get the data.

In other interesting news, it looks like the water heater cycles on/off enough times during the day to get between 1 hour 30 min & 1 hour 45 min of actual "on" time just keeping the tank warm in hopes that I will use some hot water.  This is a trend I saw earlier but I want some decent data on disk to back it up. 

There are two things I'd like to compare that data with.  First, I currently have the geothermal DHW preheat turned off for the winter months.  I've never gotten a clear answer from the hvac people regarding if it should be left on or not.  I'd like to see what affect turning it back on has if any.  Second, I'd like to see how often the water heater turns on when the geothermal is in AC mode and the DHW preheat is on.

Tuesday, March 1, 2011

TED 5000 Load Profiling

Good news for the TED 5000, I've found a way to work around the problem with the load profile tab not showing
any historical data.  Since the TED web site didn't want to easily give up their api, a few internet searches led to what I needed.  I can query the TED gateway directly with an http request and get an XML document returned that has all of the load profile historical data.  I like this method even better than just accessing the TED via IE as now I can retrieve the data and store it so that I can use it as I see fit.   I'll be adding the ability to retrieve this data to my HA software soon.

   <DATE>03/01/2011 19:33:58</DATE>
    <DATE>03/01/2011 19:28:10</DATE>

My Half Project - Degree Days

As part of my effort to figure out where I'm at on energy usage and knowing that heating and cooling are a large part of my electric bill, I did some research to help understand what affect outside temperatures have on my electric bills.

In looking at the last three years worth of electric bills I was surprised to find out just how consistent my energy usage has been.  I had less than 5% difference in kwh's used across those three years.  Degree day calculations for those years is a little different story though with an almost 17% difference.  What I found interesting is that the degree days for 2010 were much higher than the previous two years but my energy usage for 2010 was lower. 

When I look at the monthly kwh usage a trend definitely emerges, I spend more to cool my house in the summer than I do to heat it in the winter.  However, when I look at the degree days that shouldn't be the case.

Obviously something else is going on here.   I believe that what's happening is solar heating of the house via the large expanse of south facing windows that have no blinds or shades.  The sun helping heat the house would lower the energy usage during the winter and would increase it during the summer.  Installing shades will be a project for this spring.