High Electric Use from well to pond open loop system?

Discussion in 'General Discussions' started by MefromMichigan, Dec 15, 2010.

  1. MefromMichigan

    MefromMichigan New Member

    Hello, I am new to Geothermal and hope you can give me some ideas as my electric bill seem higher than normal!
    I live in mid-Michigan.... burr it's COLD! I have the following system:
    FHP ES060-1VT Open loop well water system. (dumps to a pond)
    volts=208-230v Phase: 1
    HZ: 60min. volts: 197

    Blower mtr (ea): 208-230v
    6.80 FLA. .75hp

    Minimum circuit ampacity: 43.1

    Heating: A20 - W20/W10/80
    19/16/13 kw
    Model HP150 - 1XS/M
    Kw 14.4

    The well water pump is 5hp. for domestic use and the heat pump It says:
    Franklin Electric H.P. 3 Volt 230 Hz 60 PH 1
    Cont duty date 02A19 R.P.M. 3450

    There are 5 big blue tanks. (each about 3 feet tall, I don't know how many gallons).

    Our electric use for whole house use is 150kw daily x 10cents per kw = an electric bill of $450 for 30 days. :confused: This seems very high to me.

    (Note: The auxiliary heater (which I understand to be heat strips) was kicking in, and we now keep the thermostat at a steady 65 degrees so now they don't come on at all... with the heat strips we were looking at a bill of $900.)

    My house is 3000 feet over a ground floor and an upper level. I think its insullated "average" but I'm not sure. (the basement level is not heated)

    The geothermal unit kicks on several times per hour. If I had to guess (I haven't timed it) I would say it is running 60% of each hour.

    Based on the numbers I provided above, does $450/month for electric seem high? Is a 3hp well pump too big? Do you need other data from my unit? is there any other way to make it cheaper? (we are already wearing several sweaters to keep it at 65 degrees around the clock). Thanks for your time!
  2. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    I do not like sweaters

    so I got into HVAC. As I type am waiting for my feet to thraw.

    I feel your pain.

    To a Cleveland Ohio boy who sent the wrong team to Buffalo, no that does not sound to high. Turn off all the electronics for a month, including power stealing stuff, run the t-stat to 75 and call me in the morning.


    That sounds OK.

    Last edited: Dec 26, 2010
  3. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    I don't know what depth the well is at. 3 hp well pump sounds way oversized for a 5 ton system needing about 7.5 gpm. Other than that, given $150 "base load" for your lights and appliances (unless you tell us the shoulder season without heating and cooling is much less), $300 for 5 tons of geoheat during December, January and February sounds normal. 5 tons are usually $1200/year, $100 for DHW and $200 for A/C in our neck of the woods. Just ballparks.
  4. m159267

    m159267 New Member

    Not an expert so I am ignoring all numbers and specs save for the 150 KW / day for a 3000 square foot home. In my book that is really excessive. If you have an electric bill from Sept-Oct that usually gives you an excellent indication as to your non-heating-cooling load costs. I am located in the mid-west conditioning 3600 square feet - all electric home w/ 5 ton closed loop W.F. I also have an outdoor hot tub that we use a lot during the winter.
    My daily KW average for the past 5 years (I keep a spreadsheet):
    2005 -- 37 KW / day
    2006 -- 39 KW / day
    2007 -- 46 KW / day
    2008 -- 45 KW / day
    2009 -- 39 KW / day
    The biggest monthly electric usage in my 6 years in this house averaged 73 KW day for the month (Dec-Jan 2008).
    If your house is 'leaky' and full of family taking showers and doing laundry, cooking, etc - maybe your high usage is to be expected (assuming house is all electric).
    I would be interested what your EWT / LWT is as well as cold air return and heat pump temps.
  5. MefromMichigan

    MefromMichigan New Member

    High Electric Use - here's my EWT, LWT, GPM

    Yes, our electric use is HIGH and we are freezing at 65 degrees and not turning any lights on in the house and only have 2 people. Our house is 4000 square feet but we only heat 3000 square feet of it.
    Our Bosch FHP, Open Loop, 5 ton unit, with 3hp well and 5 xtrol expansion tanks is:
    EWT = 56 degrees
    LWT = 54 degrees
    GPM = about 9
    The unit runs for 8 minutes, 3 times per hour. We leave it at 65 degrees 24/7.
    We do have our hot water heater attached to the heat pump.
    Could be: a) well is clogged from bad water quality or b) something with compressor?
    Why is our electric bill $450? (150kw per day)
    Also, in trying to stay warm, we recently closed off some registers in unused bedrooms. Is this bad for our possibly oversized 5 ton unit?
    Thanks for helping - we are unhappy with geothermal!
  6. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    For purposes of analysis (educated guesswork) I'll postulate that heating is using 120 kwh / day, leaving 30 kwh / day for balance of house. That may be high, that is, conservative for heat.

    May I assume that running 3x per hour at 8 minutes means it is running just 24 minutes per hour? Even at 30 minutes per hour that works out to heat consuming 10 kw. That is not consistent with what I'd expect from a 5 ton unit.

    Unless the 1000 SF not heated is really well isolated from the rest of the home, it is effectively within the envelope and must be accounted for in terms of heat loss. It may feel "unheated" at 5-10 degrees colder than an already chilly 65*F house, but it is still losing heat. Closing registers can cause air pressures to rise above limits in supply ductwork. This reduces efficiency, increases power consumption, and carried too far, may cause the unit to trip on high refrigerant pressure or high compressor amps.

    The 2*F waterside delta-t is an important clue that something is badly wrong. 9 GPM and 2*F works out to a heat extraction rate of only 9000 btuh. A properly functioning 5 ton unit would extract 4-6x that amount from loop water.

    Unless the water is coming from thousands of feet down, 3 Hp is a huge well pump motor for 9 GPM plus normal domestic uses.

    The most plausible explanation to me is that the geo unit is running very poorly, possibly owing to a severe undercharge or scaling, and that 5-8kw of aux strip heat is running whenever the unit runs. If the waterside heat exchanger were really badly fouled this could result. A pressure check on the low side service port would help sort this out. A brief switch to cooling mode while measuring leaving water temp, amps, and possibly also high side pressure would add valuable info as well.

    Please measure and post your leaving air temperature from supply register(s) pick one very close to unit and one quite distant - that would provide insight as to duct losses. Absent aux strip operation leaving air temp shouldn't be much above 100.

    A geo-experienced tech able to fog a mirror would be able to sort this out in 30 minutes or less, that is, identify the cause.
  7. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    I agree with Curt, you numbers do not match up. Either you have a huge flow from you way oversized wellpump, or your heat extraction is very bad (more likely). You should get about 10 degrees delta on your source side with 9 gpm flow.Likely your aux heat is on, and the pump running 24/7 but extracting not much heat, both explaining higher KWHs.
  8. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    A properly designed system in mid MI should be running most of the hour with our current temperatures. 8 minute run times suggest a problem in itself.
    You've mentioned your location as both mid and southern MI.
    I imagine I could help if you are within our service area.
    BTW do you have lawn irragation that calls for the large well HP?
  9. MefromMichigan

    MefromMichigan New Member

    High Electric Use from well to pond open loop system 5 ton

    I'm now tracking the EWT, LWT, GPM and leaving air temp. Over the past 10 days, the largest number I've seen for "Delta T" has been 5 degrees. (usually it is 2 or 3)
    here's a sample of the numbers:

    EWT = 55 degrees
    LWT = 50 degrees
    GPM = 8
    Air going in = estimated at 63 degrees
    Leaving Air Temp = 104 degrees.
    outdoor air temp 17 degrees

    EWT = 55
    LWT = 52
    GPM = 8
    air going in = estimated at 63 degrees
    Leaving air temp = 101 degrees
    outside temp 33 degrees

    I am suspecting that we are running on 100% auxiliary heat strips for the last 45 days and perhaps the compressor has shut down. Today I will take the cover off the geo unit and look for lights on the board.

    "Funny" (not really) a local service guy came here (from a respected larger HVAC company) and he never even took the cover off and charged us $100+.

    I have another guy coming out next week who only does geo. I am learning a lot! Especially to interview the service people BEFORE they come.

    Thanks for your thoughts,
    freezing at 65 degrees and $450 poorer.
  10. MefromMichigan

    MefromMichigan New Member

    high electric use - the well pump and tanks

    3 hp and 5 large expansion tanks:
    We actually have 2 open loop geo units in our house:

    a. One 15 year old fhp for just the basement and
    b. now a 6 month old 5 ton fhp to heat/cool the ground floor and 2nd level.

    We don't turn on the 15 year old unit in the basement to try and save money, although it works.

    I don't know why there is a 3hp cont. duty unit w/ 5 large xtrol expansion tanks.
    How much does it cost to replace the 3hp pump with a smaller one that uses less electric? And can we sell used expansion tanks and take them from 5 tanks to 2 tanks? We hardly use any water in the house for 2 people and no irrigation system.
  11. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    At 8 gpm for 5 tons you should see at least 10 degrees delta on the source side. Your compressor seems to be working, but only takes 2-5 degrees out of the water, suggesting something is wrong within your refrigerant circuit,

    Just for me to understand, how do you track or measure the GPM?
  12. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    8 minute cycles suggest exclusive aux. use. We should be near balance point in this area the last few weeks.
  13. MefromMichigan

    MefromMichigan New Member

    Regarding how I am finding the GPM - there is a float thing with a "bobber" in it and I read the top of the bobber like it tells me to. We've increased a degree or two on the "delta T" when we decreased the GPM from 12 to 8. (recommended per the bosch fhp installation manual is 8 GPM). (but we are still at only 3-6 degree delta t)

    Yes, I am suspecting we are running 100% on aux heat as well. I did take the cover off and looked at lights and the W1 aux light (which would light red) did not come on - but that might mean it only comes on when it isn't working. so I could not tell if aux was running or not. :-(

    I have a new local service guy coming out next week. I am tempted to call him up and polietly ask him not to step foot into our house UNLESS he is confident he can work on our Bosch fhp system and fix the issue. (as I have had 2 completely inadequate service guys in already). He does waterfurnace and geo is all he does. Cross your fingers.

    as a side note (i.e. another potential problem with our system) our electric water heater is connected to the geothermal with 2 copper tubes per the diagram in the book, BUT the installer didn't add the special valve that connects right going into the water heater... wondering if my water heater is actually draining into the geo unit or something.

    Someday I'll see cost savings maybe......
    In the meantime, signed:
    freezing at 65 and in debt to Consumers Energy for $450 ... and counting...
  14. m159267

    m159267 New Member

    Doesn't your thermostat indicate if you are running 'Aux' and/or 'Emergency Heat'?
  15. MefromMichigan

    MefromMichigan New Member

    We have a Honeywell programmable - one of the newer ones. We keep it at 65 Hold all the time. If we manually punch the temp up 2 degrees, it will say Heat On Aux.

    So yes, the thermostat will show when IT tells the geo to go to Aux, but I'm wondering if the Geo will set itself to Aux and not tell the thermostat.
  16. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    this is not going to happen. The Geo only does what the tstat tells it too.
  17. geome

    geome Member Forum Leader

    The WF tech department told me last year that if their Envision system locks out, the processor would tell the heat strips to energize. This is for their package units, not their split systems.
    Last edited: Dec 30, 2010
  18. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    Good to know
  19. MefromMichigan

    MefromMichigan New Member

    the service guy was out - here we go....

    As a follow up, we did have a 3rd service guy come in last week and he is VERY knowledgable about these systems and has an open loop in his home! We are making 5 changes with the goal of seeing some electric savings from our last $550 electric bill:
    1. changing from two fhp open loop systems to just one. We have a 15 year old for just the basement (that we don't turn on) and a 5ton unit for the ground and upper floors. the 5 ton unit is oversized. Our home is 4000 sq ft over the 3 floors so the 5ton unit (6 months old) will now heat all 3 floors. Just need to change some existing ductwork. The 5 ton unit is running 3times per hour at 8 minutes per run. The goal is to have the unit run most of the hour instead of cycling on and off so frequently and I understand it takes a lot of electric to turn itself on/cycle.

    2. rewiring the thermostat. There were several wires not hooked up and one that was hooked to the thermo but not the unit - it was a birdnest of wire spliced together. (reminds me of that show on TLC Holmes inspector - grin)

    3. re-hookup the hot water heater to the unit. The original hookup was missing a piece - made no sense the way it was originally hooked up - so we are going to have the tubing run to the top of the hot water heater and then out the bottom of it or something like that.

    4. do an acid flush. There were no ports added so those have to be added. We probably don't need to do that as the unit is new, but I'd like to ... and check the flush water to see what we get.

    5. potentially add a stop cycle valve to the 3hp pump and get rid of 4 of the 5 large xtrol expansion tanks.

    Hopefully I can report back in a month that we are seeing a $50 - $100 savings???

    wish me luck!

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