Newbie could use some assistance

Discussion in 'Quotes and Proposals' started by Popoff, Apr 26, 2010.

  1. Popoff

    Popoff Member

    I've recently contracted for the installation of a WF 2.5 ton Envision system in my home and am awaiting issuance of the required permit from the state to drill.

    In my initial discussions with the contractor (experienced and reputable) he stated he was going to dig 2 wells, each 280'. Last week he came out with the driller and advised that it was going to be 1 well, 300' with 1 1/4" pipe. The contract does not specify the number of wells or their depth. I have just emailed him and asked him to explain the reason for the change, which seems pretty substantial to me.

    I'd appreciate any feedback from the members of this forum as to questions I might ask the contractor as to his reasoning behind the change as well as any other comments you might care to make.

    Thanks in advance.

    PLEASE NOTE: I received a reply from the contractor after I posted this message. He states that there was some confusion since several people were involved in the quote process and his initial statement to me that my system would have 2 wells, each 280' was made in error. The 2 wells were part of a different quote for another customer. My system was always calling for the one well.

    I will ask him for the design particulars the next time I see him.

    Sorry for any confusion (other than mine) I may have caused.
     
    Last edited: Apr 26, 2010
  2. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    kind of slim on info provided, but one 300' well for a 2.5 ton system is on the short side of average.
     
  3. Popoff

    Popoff Member

    Thanks for the reply.

    Sorry about the info being slim, but that's exactly my quandry.

    How do I go about educating myself so I can ask intelligent questions of the installer?
     
  4. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Bidder should be able to provide a design document to support a particular loop configuration.

    It should account for soil composition and moisture, design heating and cooling load, max and min loop temps, loop GPM, maintaining turbulent flow, and what pump is to be used.
     
  5. Looby

    Looby Member Forum Leader

    Our 3-ton Envision (NDV038) is running on a single 450' well + 50' trench, 1.25" pipe.
    That comes to nearly 1100' total pipe (including indoor plumbing). A single Grundfos
    UP26-99 circ pump (245 watts) is just enough to satisfy WF's recommended flow rate.
    I'm getting 8 GPM w 20% methanol antifreeze. Online 15 months, works as advertised.

    I kinda like the unbranched single-bore approach (if you can get away with it). SIMPLE,
    minimum # of welds, easy flushing, no manifolds, high turbulence (Reynolds# = 5890).

    Regarding total bore length, you'll have to rely on the experience of local drillers/installers.
    (Thanks to extremely favorable geology, 150 ft/ton is more than adequate in my location.)
     
  6. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    We run ~150'/ton of 3/4" in my area. 11/4" certainly would offer more btu transfer.
    If installer's references are good, you may be worried about something that simply was a mis-statement.
    There are many things a geo installer can goof up, but vertical loops are generally (not always but it appears to be true in your case) subcontracted to drillers who may have more installs (due to working for multiple contractors) than the HVAC bidder. I tell customers flat out that they are the expert and "I think that they'll do such and such", but I will always yield to their expertise if they have a different idea.
    In my area there are not a lot of geo drillers so someone may get 3 bids on a job and have the same driller regardless of who they hire.
    Curiously, the most common geo problems I see are poorly sized equipment and poorly sized ductwork. Loop sizing goof ups are among the least common.
    Yet people always focus on the loops.........
    How did your installer's references check-out? What did other bidder's suggest? These are better measuring sticks.....
    Good Luck,
    Joe
     
  7. Popoff

    Popoff Member

    Thanks for the replies. This is a great forum!

    I've known the contractor I'm using for 10 years. He installed the HVAC when I renovated this house 10 years ago. He's one of the best in the area. I got two quotes last fall but don't remember the details. I got a fresh quote (lower than the one he gave me last fall) from the one I'm using and told him to go ahead so I've got nothing to compare his bid against.

    I will ask him for the design document to satisfy my curiousity and if I have any further questions I'll post again. He did take me to see one installation he's doing now for one of our local celebrities and I've spoken with 3 others that he's done installations for. Everyone says he's great.

    I tend to be a worry wart, especially when it comes to something this significant. I'll feel better when the system is up and running. I got another $500 propane bill just today so I'm all the more eager to get this thing going.

    Thanks again for the responses.
     
  8. Popoff

    Popoff Member

    Installed the 2.5 ton WF NDV026B and have had some unexpected, and yet to be accounted for, problems.

    First, my electricity consumption for the initial months usage was significantly higher than the other similar periods in the last 3 1/2 years. 1230 kwh as opposed to the usual 700-800 kwh during the previous 2 prior periods. Granted, it's been a hot summer but this seems inordinately high to me and very disappointing as well. I previously was running a 2.5 ton Carrier central air unit installed in 2000.

    Second, there's a constant whine coming from the system when it's running. I compare it to the sound of a wood chipper running at full speed (but with no wood being fed) in the distance. At first, that's actually what I thought it was. I hear the noise equally when I put my ear to either of the circulating water pipes, but not in the ductwork. I believe it's being transmitted from the pipes through the metal brackets that support them into the floor joists. The intensity of the sound varies in different parts of the house. It's actually loudest in the corner of the house that's the furthest away (~50 ') from the WF unit and at least 20' distant from the nearest incoming and outgoing pipes.

    The contractor is coming next week but I wanted to educate myself as much as possible prior to his visit.

    Thanks in advance for any and all input.
     
  9. geome

    geome Member Forum Leader

    We hear some noise telegraphing through our loop pipes in the crawlspace below our master bedroom (20 -25 feet away from the pumps) with our system. We mainly notice it at night when things are relatively quiet. Fortunately the sound isn't too obtrusive for us. It sounds like your noise is a bit louder.

    In the main section of our house, we have Armaflex pipe insulation on our loop pipes, and the hanger straps go around the insulation (to the floor joists). This may give us some insulation from the vibration/noise. In our crawlspace, the pipes are not mounted to the joists.

    Are your thermostat settings the same as with the old system?
     
  10. Popoff

    Popoff Member

    Thanks for the response. I'm in the process of looking up and compiling CDDs for our area for the last couple of years so I can come up with some sort of meaningful comparison. We barely used the AC last year since it was a cool summer, so I have to go back to 2008.

    Good question about thermostat settings. As I recall, we kept the t'stat at 78 degrees in 2008 and, with the new system, are keeping it at 74-75 degrees. Would that be enough to account for the dramatic increase in kwh?
     
  11. geome

    geome Member Forum Leader

    Not sure on how many more kWh can be expected from every degree of additional cooling (or heating), everything else being equal. There are lots of variables (amount of sun, wind, insulation, air infiltration, etc.)

    This is way out of my area, but my guess is that from the thermostat setting where the system starts to run (again, everything else being equal, and single stage equipment), to the setting where the system runs 100% of the time, I would expect the system would run exponentially more for every additional degree of heating or cooling. It seems to work this way in our house, but I have never bothered to record data (since everything is not equal and I didn't feel I could get meaningful results.) Maybe someone else can shed some light on this?

    Funny that you mention cooling degree days. My original response suggested that you get input from Ona regarding this (but I'm trying to keep my responses shorter) (I'm failing miserably.) She is good with this type of comparison, but I haven't seen her post for a while... :-(
     
  12. WF_Inc

    WF_Inc Member

    Popoff,

    Unfortunately, noise is very difficult to resolve without being present at the unit. We would suggest having your contractor contact our technical support staff while in front of the unit. They will be able to offer suggestions and work with your contractor to resolve your concerns.

    Your installing contractor will have the design criteria of your system, including the building heating and cooling loads, set temperature for the thermostat, and balance point for auxiliary heating. From this information, they calculate the estimated operating cost based upon using the average weather data from a 20 year history. We would suggest contacting your installing contractor and have them review your utility bill verses the estimated operating costs they projected.
     
  13. Popoff

    Popoff Member

    Contractor was here today with local WF rep.

    The rep heard the noise and made suggestions to the contractor as to possible causes and solutions. Contractor will follow up.

    As far as electricity usage, WF rep looked at bills and CDD history and states that system is performing beautifully. I consider my self as fairly savvy but could not understand his explanation, even though he tried hard.

    Briefly, in July 2010 we had 191 CDD and 1230 kwh, July 2009 (very cool and hardly any AC usage) 44 CDD and 794 kwh, July 2008 92 CDD and 751 kwh, July 2007 56 CDD and 765 kwh. Best I recall, we kept the house at 78 when we used the AC in previous years and 74 this year with the WF unit.

    At this point, it looks like I will have to sit back, accumulate a few more bills and, hopefully with assistance from members of this forum, figure it out in terms I can understand.

    Makes no sense to me. Ideas anyone?
     
  14. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    With little AC usage in July 2009 you used 25.6 kwh / day. That implies house baseline use somewhere in the low-mid 20s kwh / day.

    This July was 3-4 times hotter and for whatever reason you set thermostat at 74 vs 78. Dropping the setpoint that much has a substantial effect on system run time.

    Every degree of change in the thermostat setting for all of July equates to an effective change of 31 CDD. The drop of thermostat setting from 78 to 74 for the month of July adds 124 CDD. Couple that with this year's significantly hotter weather and it becomes hard to criticize the extra 436 kwh used in July 2010.

    What would have been the kwh use by the older system set at 74 deg F during a month as warm as July 2010? I suppose we'll never know, but it seems a valid question to ask.
     
  15. WF_Inc

    WF_Inc Member

    Popoff,

    We were unaware that your contractor had been in contact with someone from WaterFurnace. Please provide the name of the contractor you are working with, as well as the name of the WaterFurnace representative that visited your home. Our goal is to assist you and your contractor in finding a resolution. Is there any further information that might be helpful in this process?
     
  16. geome

    geome Member Forum Leader

    I never thought of looking at thermostat adjustments like this. Great idea - Thanks. I just added this to my "Favorite" posts. :)
     
  17. WF_Inc

    WF_Inc Member

    Popoff,

    Thank you for the additional information. We have sent you an email with a chart showing the difference between CDD in July of 2009 and 2010, for Boone, North Carolina. This information was from www.weatherdatadepot.com. According to this chart, the CDD increase by 141% from July of 2009 to July 2010. Please keep in mind that extreme weather conditions may cause longer run times, which in turn could result in elevated electrical usage.

    “Best I recall, we kept the house at 78 when we used the AC in previous years and 74 this year with the WF unit.” (From previous post by Popoff)

    Decreasing the set temperature by 4 degrees increases the cooling load on your home. This, again, may have also contributed to the increased electrical usage.

    We have been in contact with your contractor, as well as the territory manager that visited your home. They have confirmed that your equipment is operating above manufacturer’s specifications. At this point, we are unsure of how we can assist in resolving this issue. If there are issues with the equipment, we are more than happy to work with you and your contractor in resolving the issue. Please keep us informed if you should need assistance in the future.
     
  18. geome

    geome Member Forum Leader

    We recently changed our setting from 76 day/75 night to 77 day/75 night during this heat wave. Even 76 day/74 night may help your electric bill a great deal if you won't have a revolt on your hands. Make it 74 a several hours before bedtime to let the house cool down.

    Hard to evaluate the system between the heat wave and the thermostat setting being 4 degrees lower. Do you have any neighbors with conventional HVAC systems that you can compare your bills to?

    I use my neighbor's bill as my benchmark. About $400 for him, $188 for us.
     
    Last edited: Aug 5, 2010
  19. Popoff

    Popoff Member

    Geome and Engineer, thank you! I will have more to post in the next day or so concerning what I'm finding out.

    A special thanks to WF for their prompt response and helpfulness. Let me assure you, there is no "issue." The timing of my first month with my new WF system and record breaking heat produced an extraordinarily high electric bill . Now that I'm seeing things in better perspective, I'm calming down. (-:

    I think the contractor, the WF rep, and WF corporate have been impressive in reacting to my concern. I'm most appreciative.
     
  20. geome

    geome Member Forum Leader

    WF, thank you for the degree day website link. The other site I use is good for downloads (up to 3 years for free.) This site lacks the free download feature (as far as I see), but it has lots of other nice features.
     

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