Researching geothermal heat pump system, 1 quote so far, concerned.

Discussion in 'Quotes and Proposals' started by tstolze, Jun 20, 2010.

  1. tstolze

    tstolze Member

    First of all thanks for the forums and any help/suggestions received.

    I am researching a Geothermal system for my 16 year old home, 1160 square feet, original 2-1/2 ton a/c, 15 KW strip heat, and electric water heater.

    I have had two contractors I have crossed off already, one had poor/lack of communication, the other didn't show up as scheduled and called the next day to set another appointment. So the quoting process is proceeding at a snails pace.

    I did have one contractor come out, when I called they said they have been running $4-5000 a ton. He arrives on time, measures duct work, windows, insulation and size of my home. We go outside and look at areas for vertical loops, we agree on two different areas, and agree to get input from driller. He stated one loop per ton drilling to 120 ft.

    I received his load calculations, it was run on Adtek Accuload 1.4.1.
    St. Louis, MO area
    Summer outdoor drybulb 95, indoor 75
    Winter outdoor drybulb 0, indoor 70
    Heating-24580 Btuh, Cooling-23238 Btuh

    He says he would be comfortable installing a 2 ton system, and that he was waiting on the driller to get back with him.

    A few days later I receive an email with my quote. Below is a copy and paste of the wording with the drilling company name removed.

    Remove and haul away old equipment. Install new Bryant 2 ton geothermal package unit with 12 KW
    back up heat and hot water generator.
    Reconnect to existing ductwork and electric. Install new digital programmable thermostat.
    Drill two wells in yard to be done by driller. Pipe existing hot water heater to hot water
    generator in new unit. Price includes all labor and material
    to complete job.

    The total came to 13,990, way above his statement of 4-5000 per ton, although it comes in that range with the tax credit, that was not mentioned when he stated the rough cost per ton. I am concerned with the lack of details on the unit and have requested additional information on the model I was quoted, single stage, two stage, etc. The 12 KW of backup heat seams strange as we discussed that I have backup already, although the strips are likely a small percentage of the cost.

    Sorry for the long first post. I plan on continuing this thread as more quotes arrive, any input is appreciated, Thanks.
  2. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader


    Good price for a vertical 2 ton system. Load calculations included.

    I would suspect a cheaper heat pump for this price. Works for some as you're loads look balanced.

    Economies of scale definitely enter this work. So his price/ton may be leaning towards a larger system.

    Contractors will generally gravitate towards less details as this keeps quotes from being dismembered, but we need to understand different requirements for different clients. Share your expectations with the contractor(s).
  3. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    I would investigate some other drilling depths in your kneck of the woods that are used as "rule of thumb". Nation wide the thumb seems to have settled on two camps.
    Camp one 300' of pipe per ton vertical
    Camp two 400' of pipe per ton vertical

    Neither camp would redily sign off on 240' of pipe per ton vertical.

    If there is something unique about the geology in your location this thumb may be o.k., If it were me I would do some investigating before I pulled the trigger on that amount of pipe for your load.
  4. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    I agree with earlier replies

    Although I'm in Camp 3 - we need 500+ feet of pipe per ton - cooling-dominated climate with 71 deg deep earth temp.

    Price per ton will be significantly higher with a 2 ton unit. $14k seems like a very good price. I don't think I could touch that down here even with cheap labor and low overhead.

    Strips are so cheap there is little point in trying to reuse existing. I don't quite understand needing 12 kw of strip for the posted heat load, but it may be that strips in this case come in 4 kw increments and 8 seems light. 12 is more than enough to run entirely without compressor, but again, strips are very cheap especially if existing electric services 15 kw.

    I'm a bit suprised that heat and cool loads are so close together given the design temps. I routinely see nearly matching heat and cool loads but I'm near Jax, FL where winter design temp is 30, not 0. That's not to say your load calcs are incorrect, just odd. A very tight well-insulated house with heavy west glass could legitimately have that result in STL.
  5. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    Seems like a very good price.

    Make sure they don't cut corners. We would be at about 18K with a horizontal loopfield and two tanks, but also with an advanced 2 stage heatpump with 10 year warranty. Make sure they use thermally enhanced grout, and grout all the way up. 240' for he loop is on the short side, I have yet to see an application where this would be enough. Keep in mind that even pond loops with water all around are 300' at minimum/ton. May be your installer has a good rationale, would certainly like to see/hear his response.
    Cutting corners with geo does not work....
  6. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    suspiciously so.
    sizing makes sense based on load.
    check references.
    good luck,
  7. tstolze

    tstolze Member

    Thanks for the replies everyone. I did get specifics on the equipment, it is a two stage system with a 10 year warranty on the compressor and refrigeration circuit, 5 years on everything else.

    As far as my house, 9 of 13 windows face west, well insulated, dual pane windows.

    I had a second contractor out today, took the square footage and decided I need a 3 ton unit.......I politely asked him how he came to his conclusion, he stated "experience". He didn't ask or look at my windows, insulation, or even ask to see my electric usage with my current system. As of now he is off my list.

    I have calls into two others, one which is listed on this site.

    I will have to do some research and ask for more specifics on the loop depth.
  8. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Care to discuss the advantages/ disadvantages and wild mis-application of this product add nauseam? Diagnosis without prognosis is malpractice? What btu and why? What silica content of sand? Whose product?
  9. tstolze

    tstolze Member

    Contractor 3 was out this morning, was verbally leaning towards a 3 ton unit for heating. When I mentioned some specifics about the house and made available to him our current electric usage he then said he would do a full load calculation and make his decision from that. He then looked at all the specifics I would expect for a load calculation to be done. He said he has been using 150 ft wells with no complaints, and gave me 3 reference customers without me asking.

    I will be installing a new water heater during this process also as the current unit is 16 years old. When I mentioned this to him and that I would like to move it he said if he gets the job he would install a new unit at no charge as long as I had the unit at the house for him.

    I look forward to getting his quote....
  10. geome

    geome Member Forum Leader

    Sometimes there is some leeway in quotes. We were able to get a DSH and a two stage compressor upgrade for our second floor unit.

    It would be interesting to know if the references can give you their EWT (entering water temperature) midway into the winter (for example) since well depth has been questioned.
  11. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Sounds like you have a prospect. I hope his number comes back in your budget! Keep us posted.
  12. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    In your first post you were referring to 120' of drilling, which means 240' of pipe, per ton. 150ft of borehole (300ft of pipe) is average for soil with good conductivity, using 0.75" sdr 11 pipe.
  13. tstolze

    tstolze Member

    I will be talking to the first contractor within a few days to clarify the depth of drilling. I am sold on a 150 ft minimum.

    I did receive my quote from contractor #3, he figured a 3 ton unit with 10 KW of backup. He called and talked to my wife about his load calculations, she said he figured 2.2 tons for heating. that is why he quoted a 3 ton. My thoughts are to let the backup strips handle it when it gets really cold. For reference we have only been below zero 4 nights in the last 5 years. His quote was almost $2000 above my only other quote, but he quoted 3 tons, the other is a 2 ton. Virtually identical except brand(Bryant/Waterfurnace) and system size.

    I would really like some input on the size, I am assuming I want close to the calculated loads.

    I have one more contractor coming Monday am, then I will be making my decision.
    Last edited: Jun 24, 2010
  14. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    I am showing about $38 difference of operating costs in favor of a 3 ton system, given that your load calcs are correct (24,500 BTU for heating), using St. Louis weather data and New York state electricity costs (ouch)
    Aux heat usage is 1% for 2 tons, and 0% for 3 tons.

    Using a soil conductivity of 1.4, which is average rock, your bore length should be 460 feet with a 3 ton and 345 with a 2 ton system, mostly due to the cooling load, when you want to limit your EWT to 95 degrees in the cooling mode.

    With 300 ft of borehole for a 2 ton system, your operating expenses go up $17 per year due to the slightly lesser performance of the loopfield.

    240 ft of borehole for 2 tons brings your EWT outside manufacture's specs, unless your ground conductivity is better than average rock.

    This is data for climatemaster, waterfurnace should be similar.

    Keep in mind that the installer has to stand behind his install, so if he knows something what we do not.....
    Hope these numbers help.
  15. tstolze

    tstolze Member

    Here are the current electric rates we pay(they did get approval for ~10% increase soon)

    Summer $.0863 KWH

    Winter $ .0612 for the first 750 KWH, $.0412 for everything above 750 KWH
  16. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    OK..I am jealous again....the $ number are based on 14 cents/kw/h

    So take the numbers x 50%.
  17. tstolze

    tstolze Member

    Received quote from contractor 2 in the mail today. 3 ton Bryant, no load calculations done, $1600 above the Waterfurnace 3 ton quote.

    ( I had already decided against this contractor as he refused to do any load calcs.)
  18. tstolze

    tstolze Member

    The last contractor called earlier to try and reschedule our appointment for earlier in the morning, I told him I couldn't do it earlier. Then he said it would have to be later in the week, at that point I told him not to worry about coming out.

    I have been using the reliability of the quoting appointment as my first gauge of each contractor. If you can't setup an appointment and stand by it when I am getting ready to invest in your company, then how are you going to act if/when I have a problem with my/your system. Maybe a bit harsh, but 2 of 6 tried to change appointments/didn't show then tried to change, 1 called a week after he said he would call. Of the 3 that did come out on time, 1 didn't do any load calculations, 1 said he did, but has yet to provide me with them.

    I have had several conversations with contractor 1, he has double checked the load calculations and feels very comfortable with them. We spoke about well depth at length, he said his quote was for 150 ft minimum, I have asked we go to 200 ft beings the system is closely matched with the load. He agreed and was going to adjust the quote for me tomorrow. He has agreed to move/install my new water heater during installation. He said the driller is running 3-5 weeks out, so if we finalize tomorrow it would be several weeks before the install.
  19. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    good luck and keep us posted.
  20. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    4-5k/ton is more accurate for larger systems. 2 ton units are not large enough that the number covers incidentals.
    We do not employ a commission sales staff and tell folks from the get go that service takes precedence over estimates. I hope folks wouldn't automatically reject us if we had to reschedule.
    2 ton plan sounds good, check references.

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