Pennsylvania Help - $8500 in electric in just 2 years!

Discussion in 'Maintenance and Troubleshooting' started by Suzanne, Jun 6, 2016.

  1. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Since I am so stupid, I did not mention that I read the I/O manual very carefully. I saw several issues with the control system algorithm as it ships from the factory I would change. I do not think the capacity of the machine is enough for heating with out help.

    If that money saving geo system can not keep up and the control turns on the electric heat you have an electric furnace and not a geo system.

    Last edited: Jun 12, 2016
  2. Suzanne

    Suzanne New Member

    Doc -

    Just to be clear, the 3100 figure for Jan & Feb is a 12 month avg.....meaning Jan 2015 to Jan 2016, the monthly use averaged out to 3100.
    Actual numbers, going by actual meter reads:
    Dec 2 - 9535
    Feb 2 - 19070
    That's a two month use of 9,535, or almost 5,000 a month! (minus my 900, it's 4,000 of just geo use.)

    What does everyone else's kWh usage look like? I wish I had real systems to compare because this is hurting me not helping :-/

    - Suzanne
  3. Suzanne

    Suzanne New Member

    Mark -

    That's exactly what I feel like I'm paying for - an electric heating system. Which is INSANE if you live where I live!

    I need to figure out how to fix this problem.

  4. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    I would do three things.

    A good heat loss.

    Alter the control system's thinking to dis-allow aux heat as much as possible.

    Tighten the envelope.

  5. Tamar

    Tamar Member Forum Leader

    Suzanne, Doc and I were both referring to the post from Friday that seemed to have monthly numbers.

    Here is my electric usage for just geothermal (we have a separate meter). Our other usage is between 600-800 kwh year round. We have an old Victorian (around 3100 sq feet) in Minnesota, and our system was mostly replaced after the first system suffered from poor design and much higher heating usage then what's shown here. You can see the system really shines in the shoulder seasons, and then uses more electricity in the coldest months.

    Attached Files:

  6. Suzanne

    Suzanne New Member

    Tamar - Thank you for sharing your data. That's the first concrete example I've seen of what someone else's geo is using (kWh.)

    I would love to have a separate meter on my geo system. Was that put on during initial installation? Any idea of what one of those costs?

  7. Tamar

    Tamar Member Forum Leader

    Suzanne, the separate meter was part of our initial installation, because Xcel Energy offers a cheaper rate for geothermal if it's on a separate meter, and I guess the installer figured it was worth including that cheaper rate to sell the system. We were on the hook for adding a new box in the house for the new circuits, which I think was about $350. I would not add it if there isn't a payback through lower electric rates.
  8. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    thanks for clarifying. Yes, 4000 kwh per month for a 3 ton system indicates a lot of run time and electric resistance usage if the system is operating correctly. I have that much in the peak season for my 6 ton heat pump.

    1) your contractor needs to check if the operation is correct and the unit work with the correct capacity. So he needs to measure and calculate the heat extraction.

    2) tell us a bit about your house. Age, size, insulation status, do you have previous oil/propane consumption?

    Above is a 3 ton system serving a leaky , 1500 sqf house. You can see the monthly consumption at $0.11 cents/kwh. It does not include the aux heat, which is $150/year.
    You can see more live data on our website.
  9. Suzanne

    Suzanne New Member

    Thanks, Doc. Those were interesting graphs to look at, but I'm not sure I understand all of them. From what I can understand, it does look like that system is cheaper to run then mine.

    My house, a cape cod, is 1,000 sq feet on the 1st floor and about 500-700 on the 2nd floor (I can't remember and keep forgetting to measure that.)
    Built in 1958, the insulation is old and lacking. I know it needs more in the attic, and saw the insulation in the walls when I ripped a small window out and put a large one in. It was the 'roll' kind (not loose) but it looked kind of thin. Insulation was my next big project.... The house is pretty leaky I'm guessing. I have done anything to seal it. I just put on the storm windows when winter comes.

    The last fuel usage I have recorded is the winter before the geo install. I only have the cost of the fills, and not the gallons, but I know the cost was at least $3/gallon:

    14 Oct 2011 734.66
    30 Dec 2011 603.85
    11 Jan 2011 639.26
    24 Feb 2012 551.20
    24 Mar 2011 538.50

    If you ignore the last fill figuring I didn't finish using it all that season and add up the other 4 fills, it comes out to a little over $2500 - at $3/gal that would be about 830 gallons. That's just one years example. I know I spent over $3,000 in oil other winters but the price varied a lot as well. On top of that, though, I supplemented with a ventless propane wall heater in our livingroom, which kept things comfortable in the main living area.

    The contractor is coming over the house today (Monday) at 4:30 to talk about things. I really do appreciate everyone's help in figuring this out. I feel a little more educated about the system, so I won't be completely clueless when we discuss it!

  10. Dinnerbellmel

    Dinnerbellmel New Member

    That's really cool Doc...a great feature for your customers. Just out of do you know the house is leaky? Did you or the homeowner conduct a blower door test?
  11. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    No blower door test. But one knows through the monitoring when the supplement heat comes on at what outside temperature, and at what wind speeds. Seeing the supplement heat coming on at 8-10F on a calm day and at 15-18F on a windy day tells me that air infiltration is an issue (or the issue). Not sure what a blower door test would have shown, beside that it is again "leaky".
    Nothing I can do about, I don't own the house, I can only heat it in the most efficient way.

    Of note, increasing the heat pump to 4 tons would have increased the operational costs by about $80 due to a lower COP, and cut down the Aux heat by $100 annually. So a $20 annual benefit. But increased the upfront costs by $3000. Worth it? I would still do the same again (3 ton) to give my customer the biggest bang for the buck.

    Things change through our better understanding on how variable speed technology emerges and operates. Down the road we will change to design for 100% load coverage with variable speed equipment.

    To Suzanne: We are doing a lot of guessing here, since we don't know the efficiency of you old oil equipment, your additional propane use, your exact gallons, but one would think that your house has anywhere between 40-50,000 BTUs/h heatless, which translates to about $1200 with geo, when it was $3000 for oil and maybe another $500 for propane. Again, these are rough numbers.

    What strikes me that even in the shoulder month, when the house does not need any heating or cooling, you have high energy consumption. For example you have 2400 kph for October, reflecting your September usage. That is much higher than the average 900 KWH you had before.

    Something is fishy, either the pumps running 24/7, and the blower runs all the time, or the electric tank runs and you are loosing heat somewhere.

    You need to hunt down your consumers. Google "google power meter" and install it, otherwise you don't know the source and you might blame the geo system for it when it is going elsewhere.
  12. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

  13. Suzanne

    Suzanne New Member

    Hi ALL - A little update.

    Met with the GEO contractor who put in the unit. He was also struggling with my 'dead' months (those of little GEO use) being really high, and therefor possibly pointing to another piece of equipment somewhere that is consuming all the electricity. None of us has a kw monitor, and I didn't want to spend another dime at this point, so he suggested a trial run of shutting off the GEO unit completely for one week and see what my base usage is for running my home.

    Started last Monday and will go until later today but as of Sunday evening, we had used a total of 160 kwh for 6 days. Monitoring it daily, the lowest I saw were 2 days at 18 each ranging to the highest use day at 35. We didn't hold back anything, been running fans around the clock, dehumidifier on, someone left garage lights on, more than usual amount of laundry done and I've been home on a stay-cation the last 10 days so I've used more electric than normal just by being here. Also, I'm using electric to heat my water (no help from geo this week) which previously was propane.
    Estimate for the month would be about 800 kwh/month.

    I also took Penelec's actual reading for May 26th (26,242) and paired it with our reading on June 17th (27028) which is 786 kwh for 22 days. That is with the GEO running to cool the house (up until the 13th when we shut it down for the trial.) 786/22 days roughly equals 1070/30 days. Seems reasonable to me.

    The conclusion of our 'trial' should at least be that we don't have a drain on our electricity somewhere in the house. And now that we have left the heating season, I'm not sure how I'm supposed to prove the GEO was the culprit of the high bills. During the Feb service call I requested, the technician said a setting was wrong (making the system think it was an open loop instead of closed) and the change in setting did seem to lower kwh usage for the remainder of heating season, which wasn't very long.

    The high usage in the 'shoulder' months is still a question. We always have left the GEO on. And I never hesitated to use it compared to when I used oil and would wait as long as possible to turn the heat on. We would be cold and wearing extra clothing until I finally turned it on. But with GEO, I set it at 72 or 73 and let run all the time. It probably did kick on some days in Sept and quite a few in Oct, but I don't think it would have been cold enough for the pumps to shut off (if settings were wrong) to protect itself and then kick on electric heat. Does that make sense?

    Any theories are welcome!

  14. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    I think you are right on target. Setting the freeze protection incorrectly would turn off the geo unit and have the electric backup heat come on. With that setting you would be heating your house with the electric heat most of the winter.
    Last edited: Jun 29, 2016
  15. Suzanne

    Suzanne New Member

    Doc - would the electric backup heat come on even in those months with little need like Sept and Oct if freeze protection was set incorrectly? I don't quite understand freeze point I think. If its 50 degrees outside and my thermostat is set at 72 so my heat kicks on a little, is that a low enough temp for aux heat to kick on even with incorrect freeze protection setting? Still trying to understand how this works.

    The contractor also mentioned the possibility of a bad computer board instead of settings being the issue.
  16. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    It should not come on in September or October, since the loop would still be warm. Freeze protection should matter when your loop is around 35F and below. 2 other points:

    Are the pumps running 24/7 or are they coming on only when the heat pump is running (which should be the case)?
    What is your deadband? Meaning when do you stop heating (temperature) and start cooling? It might be that your system is heating during the night/morning and cooling in the afternoon/evening when you keep the thermostat at 72F for heating and cooling.
    Not sure what your thermostat is set up for. Setting it to either heat or cool, have heating started at 70F and cooling at 76F might be helping here too.
  17. Suzanne

    Suzanne New Member

    I'm not sure if they run 24/7. What should I look for to know? we are just turning the system back on today after our trial shut off period. I'm at work but my son turned it on just a few minutes ago. It's 78 degrees in the house and I told him to set it for 76, wait till it gets to 76 then bump it down to 74, then once it is at 74 bump it 72. I don't know if it makes a difference cooling, but they told me it's better to go in small increments when we were heating so it doesn't kick on 'extra' effort (electric strips) to overcome the wide gap between current temp and desired temp.

    As far as setting the thermostat, once we get it back to 72 sometime today, we leave it there for summer. Once in awhile we may be bump it down to 71 or 70 (my sons don't get the cooling benefit upstairs as I do on the first floor and they sometimes turn it down that far.) For heating, I keep it about the same 71 or 72. And we don't use 'auto' - I assume that will kick the system into heating or cooling, depending what is needed. I keep it in cooling mode or heating mode, depending on the season. The fan, on the other hand, I keep on, because I figured that is just circulating the air and doesn't use much electricity. I hope I'm not wrong on that one.

    There are more detailed settings for the thermostat that I don't have anything to do with, but maybe I should? The technicians set that up - controls the temperature gap or swing, when 1st stage, 2nd stage kick in.... I don't know my terms well but hopefully you understand what I referring to.
  18. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    Makes no difference in cooling. For heating you don't want the Aux heat to come on.
    The fan can use a significant amount of electricity. Turn the fan off and see your electricity usage for a week.
  19. mrrxtech

    mrrxtech Member

    I have a few ideas to help out.
    In order to gather data for your Geothermal Unit to determine performance & understand the problem you are experiencing you can do the following:
    1) Add temperature probe/instruments to your Geothermal Loop Input and Output lines at the unit. This can be done by using pocket thermometers as seen on ebay:
    Place them in the insulation (or add foam insulation like pool Noodles on the pipes) to measure Loop Water In and Loop Water Out temperatures. This will tell you the Loop Differential Temperature which will help those who have an owners manual determine how well your Unit is working.

    2) Use two additional temperature probes one in the Unit Air Return Air duct and one in the Outlet Air duct. This will tell you the differential temperature across the unit.

    3) If you have Peach Valves on your Geothermal Loop Water Inlet & Outlet connections, which are similar to Basketball or Football air valves, in operation. A pressure probe for measuring Loop Water Inlet and Outlet pressure can be used to measure your Loop Water Flow by converting Differential Pressure across the unit into loop flow using your Owners Manual for the Geothermal Unit.

    Assume that you find that your two wells don't provide enough heat sink in the winter to keep your Unit from freezing up based on data you obtain from adding the above instruments, what can you do?
    You have 2.5 acres of land. Assume you only use 2 acres, then you have 1200 feet of border around your proper to place additional horizontal loop if you need it. You can add a horizontal loop to your wells by digging 4 to 5 feet deep using a rented Riding Trencher that digs up to 5 feet, and put your Adult Sons to work trenching around your property avoiding tree roots and other objects. You can use Google Earth to map out a good path around objects and measure the length of Horizontal loop you need to add. This would be cheaper than digging another well and accomplish the same result if designed correctly.

    There may be warrantees to worry about, but if you have limited resources you can do it yourself after working out the details of where and how to tie into the existing Loop Lines, and loop materials needed .

    Someone may object, but if this were my problem I would fix it myself if there was no legal recourse for getting the installer to fix the problem free, or simply make the system work as it should have after installed.
    Last edited: Jul 2, 2016
  20. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    1) The pocket thermometer with analog display are not precise enough for temperature measurement, and will give you inaccurate numbers at best. if you are off by 1F in cooling mode you are off by 10-15%. Especially with a needle thermometer you do not get anywhere close to a precise reading.

    2) Delta t on the air side does not tell you much if you don't know the air flow.

    We have no reason to believe that the unit is freezing up in the winter. Also a heat sink refers to discharging heat in the summer time to the source, in this case the ground, not a . To tell Suzanne right now how to add a horizontal loop to a without knowing pressure drop or flow impact, and without having any indication that the loop is not performing, without any indication that here unit is freezing up, and without her knowing how to fuse in Tees into the existing header, would be malpractice for a professional.

    Suzanne, your installer is responding so far, keep working with him.

    Mrrxtech, how can you keep misleading people here with your lack of knowledge?

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