SC Geothermal Quote

Discussion in 'Quotes and Proposals' started by scnewconstruction, Jun 4, 2011.

  1. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    I use Wrightsoft Right Suite Residential.

    I always follow the notion that the best money you can spend is on insulation. The purpose of the manual J at this stage is to correctly size the equipment. You were between a 4 and a 5 ton, leaning more towards a 4 ton, but I doubt that you would get it down to a single 3 ton unit. The percent increments become much larger once you get down in unit size. So yes, you will save more energy by putting in more efficient windows, but in terms of heatpump capacity, you would be pushing the envelope. In addition, you want some response time. Plus, we are doing all this over the internet, so this is just advise, you need to get someone local who correctly sizes your system and builds it efficiently.
  2. scnewconstruction

    scnewconstruction New Member

    Oh Great....

    Ok I own a house built in 1911 that was in a very bad state of repair when I purchased it. I have owned it for over 16 years slowly improving as finances and time allowed. Early on I did a lot myself and as I got older and my life grew busy (wife, kids, work) I hired more and more of it done along the way learning a LOT of hard lessons about people and companies doing the work.

    Basically I am no longer the trusting sole I used to be and I do my own research to confirm what people are advising me.

    My issue now... since I think the HVAC load calculations are bogus I wanted to see what my builder thought of them. The builder has built over 1,200 homes in my area and would hopefully have a good idea of what is bogus and what is not. I wanted to see what the builder thought of the calculations with out tipping my hand on what I thought. TRUST is a HUGE thing for me - if I don't trust you then why would I give you the work?

    I have NOT signed a contract with the builder yet.
    When the builder priced the house he indicated 2 1/2 tons per floor before I started in about wanting spray foam insulation etc...
    Then the contractor comes in with 4 tons per floor - I ask the builder to get the load calculations from the contractor which he does.

    His reply to my query about what he thought of the calculations was:
    His initial thought was it would be 3 tons per floor, therefore, 4 ton units that have the option of only running at 70% with the variable speed feature seems logical to him. He thinks the contractor is suggesting a system that will operate efficiently.

    See up until this point my dis-TRUST meeter has not gone off with my builder but now it is.

    So now I'm wondering what I should do.
  3. geome

    geome Member Forum Leader

    Have you asked for, and checked out, references from the builder and the contractor? I would suggest going to see the houses and geothermal installations in person if the references will let you. While some are not fond of the BBB, a search may provide some useful information. You can also check with your building department and inspectors to see what they think of the builder and contractor.
  4. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    I would have you "relax"

    You have the check book so you are in control.

    I do not understand the "panic" in your posts. If you have given the offending contractor money and are not happy with the contract then it may be time to find help. I think GEOME said the same thing. I for one, trust his judgement.

    What to do?

    I do not know how many checks you have written and to whom. If I wanted to build a home and did not do it myself, I would be very careful with whom I dealt. I take great care when dealing with a customer/homeowner to be, to insure that the options I offer in a contract meet the buyers expectations. I have "fired" customers if we can not agree on what "WE" want to happen.

    I would stop writing checks until all your concerns have been addressed in a manner that makes you feel comfortable.

    Comfort is what it is all about, the rest is just money.

    I feel your pain, but you must stop the panic attacks, or you will loose the battle.
    Last edited: Jun 13, 2011
  5. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    A couple things here. The contractor seems to be close to target with 5 tons overall. Most contractors have no experience with geo and do not understand the ultimate comfort of 2 stage cooling, they are used to a system which just turns on and off, not one which puts a variable capacity, giving you longer run time and lesser blower speed at off peak temperatures.
    Zoning for him was installing 2 systems! Again, welcome to the world of multistage geo equipment. He might not understand that he must have the second stage run at full throttle
    at peak load in order to give you the best comfort and take advantage of multi stages.
    Two 2 stage four ton units will effectively be converted into a single stage unit in your case, running only at the single stage at peak load.
    He also does not understand the fact that going to 6 tons or below can significantly reduce the price since it only requires one unit plus a much smaller loopfield, but adds a bit for zoning for the ductwork. I just priced out an 8 ton system (4 downstairs, 4 upstairs) for a 6000 sqf new house in heating dominated climate for $48K, but settled on a single 6 ton which brought the price down to $33K with zoning, since they have 3 fireplaces on natural gas for backup.
    Most importantly, he might not understand the nuances of the geosystem and might be intimidated by not understanding the technology well, and might get the same BS from his HVAC contractor who's knowledge he depends on.
    For us it is always an educational opportunity, many builders do not like geosystems at first, since they want to get in and out, think it will create issues holding them up, and shift the customers budget away from the countertops and fancy cabinets they like to sell them themselves. They are not the one paying the utility bill. All that changes when they realize that it will help them sell their houses and make their customers very satisfied.

    The bottom line is that your builder might be very honest and acts in good faith, and the last thing he wants is a geo system with all kinds of issues. So he must trusts his contractor. Unfortunately we see it all the time that people oversize systems and run a scare tactic in order to get more money for the install, your builder might be as much of a victim as you are.
    Again, just a thought from far away, without having been there.......
    Last edited: Jun 13, 2011
  6. scnewconstruction

    scnewconstruction New Member

    Thanks DocJ - your insight has been helpful - I do believe that this is my builder's first geo install and possibly first full foam install.

    To the others that posted - I appreciate your feedback - I am not panicked but concerned - as I stated I have not signed a contract with the builder yet and no money has exchanged hands and until the HVAC issue came up I have had no concerns about the builder.

    I will discuss the Manual J calculations that I generated and discuss options with the builder.

    With the price of spray foam insulation I am beginning to wonder if I would not be better served with ICF construction - I initially threw that out as a possibility with my builder in our first meeting - I think he said it would cost too much but with 23-28k in foam I am wondering if it is now more in the price competition.

    I know this is a Geo HVAC forum but any experience with ICF?
  7. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    The last job I did with ICF

    the guy stiffed me for my profit. I took him to court and lost due to how I named a file.

    I do not have any idea as to how it worked.
  8. geome

    geome Member Forum Leader

    Mark, are you able to tell us a little more so others can learn from this? I understand that you may not be able to share this information. Thanks
  9. scnewconstruction

    scnewconstruction New Member


    Sorry to hear about your troubles. I too own a business - just not in the HVAC field - and I do not want to deny anyone that does work for me a reasonable profit just like I do not want to be denied a reasonable profit from the work I do!

    Just like everyone I just don't want to be taken for a ride therefor I am trying to do my homework. This forum has been extremely helpful and I thank you all for your input.

    Like Geome said if possible could you share a bit more about your experience?
  10. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Not much to tell.

    Stephanie and I were trying to put a per square foot number on bidding radiant floors. The idea was to stream line the work required to arrive at a job total. We priced the job long hand but the file extension contained the words square foot

    We showed up with materials and our crew to install re-bar mesh and tubing. The homeowner did not have the mud room area of the walkout basement addition ready for the concrete pour. I asked him what he wanted to do with the area in terms of tubing installation and he replied leave it out of the design as he did not want naked pipe in the area and I did not want to bury any joints.

    The job ended up about 14 square feet less the the total we intended to install. We packed the 20 or so linear feet of pex elsewhere in the slab to be. When the concrete guys had made their pour without hitting our tubing requiring a repair I asked for the balance due for the contract. He refused to pay as he had promised. He got down right nasty about paying, but gave no reason for his refusal.

    We filed a lien on the home and took him to small claims court and lost due to the missing "square feet". I found out later he took the framers, roofer and the electrician.
  11. scnewconstruction

    scnewconstruction New Member


    Ok below is a picture of the load calculations I did using HVAC-Calc.
    This is not even the foam installation nor taking into consideration that the vast majority of my windows will have considerable shading. IMO this is a worst case scenario - just a normal built new house.

    This is whole house.
  12. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    You are not going to have 29000 BTUs of infiltration in a brand new house, even without foam.
    In SC you will be cooling dominated, so you cooling load should be higher. Just ignore the heatloss, look at the heatgain. As I said, with a "normal" newbuilt house you are between 4-5 ton, with foam and high efficient windows you would be quite below it. Again, a 2 stage 4 ton Water-Air is rated for 50000 BTU/H in second stage cooling. I would question whether 25K for foam is worth it, given your climate and the efficiency of the geo system.
  13. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    You want the data you enter to reflect the home you are building, not a worst case scenario. Load software already has fudge factor.
    I agree with Doc, around here that load would suggest a 4 ton, but do away with the GIGO to be sure.
  14. scnewconstruction

    scnewconstruction New Member


    Yea I used worst case just to prove to myself that the HVAC calculations I got from a HVAC contractor was garbage. I did run a full foam and an ICF calculations and came up with 2.5 ton for ICF and a 3 ton for foam - this is best case taking into consideration all the shading of windows and such that the house design and direction of placement would allow.

    I think I will put a 4 ton unit in and call it good if I do either full foam or ICF.

    What by the way dos GIGO stand for.

  15. geome

    geome Member Forum Leader

    GIGO=Garbage In, Garbage Out
    In this case it refers to using realistic numbers as an input to get useful information as an output.
  16. scnewconstruction

    scnewconstruction New Member

    I'm BACK

    I'm still working on everything....
    The HVAC company got wind I was not satisfied with the load calculations from the builder, he called me and asked to see mine.

    We had a meeting and we discussed a lot of things - he is re-doing his load calcs orienting the house from e-w to n-s, removing the 2 fire places (since they are ventless gas anyway), changing window types to efficient windows etc...

    I have decided that I'm going to build with ICF and not spray foam so revising estimates and things is going to take some time.

    We - builder, hvac company owner, and I had a meeting to discuss. He doesn't believe that 4 tons will work - he still wants to split the system into 2 units etc... where based upon what I have read from you all in this thread I would be better served with a single unit and automatic zoning.

    HVAC guy is going to do some research and talk to a friend that has experience with ICF houses etc... Again neither the builder nor apparently the HVAC guy has experience with super tightly built homes. I know, you know, and the hvac guy knows rules of thumb do not replace manual J - that said he said that typically on new construction he has never seen greater than 650 sq ft per ton. Me telling him that from what I have seen as spectrum ranges for sq ft per ton with ICF range from 750 to 1200 with most common of 900-1100 per ton.

    Oh found out what Manual J software he uses - Wrightsoft

    Sealed attic with spray foam insulation on the underside of the roof - probabily around R30 to R38 total there.

    Wow all that to ask the following questions...
    If a single system w/automatic zoning should I have the house built so that duct work is not in the attic but between floors?

    How much extra height will I realistically need to build in to accommodate the duct work between floors if that's the answer you all give me?

    I am considering instead of a sealed 4 foot high crawlspace to put in a full basement (not a walk out basement but basically a hole in the ground). If I wanted 9 foot ceilings in the basement when finished how high should I make them to accommodate the duct work? Basically the same question as above... sorry if redundant.
    Last edited: Aug 10, 2011
  17. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    Duct is always better off in conditioned space, but you have to weigh cost and consequence.....
    for instance, spray foam in the rafters may allow less loss from ducts in attic.

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