Living and Learning with Geo

Discussion in 'Geothermal Heat Pump Testimonials' started by ChrisJ, Feb 2, 2011.

  1. ChrisJ

    ChrisJ Active Member Forum Leader

    "The Geo supply is plumed into the center (T&P) port, sometimes this is on the side of the tank."

    Mine is on the side of the tank. Maybe I am using the wrong wording but I am calling that the geo return, the water is going into tank warmer then it left.

    Which is where my problem arises, radiant return water is 65*F, goes down dip tube cooling the bottom of the tank, heat pump can't raise temp enough to keep radiant supply at 90-95*F.

    To quote myself: "Maybe I should concentrate on getting the delta T down on the radiant return, need more flow. 2 zones- Basement 4 300' loops 1/2" pex-al-pex, 1 taco 007 circulator. Garage is 2 300' loops, 40' of 5/8" pex-al-pex from 007 circlator to manifold. Plumber said we should take out the internal flow checks in the 007's, don't know if that will gain anything. Larger pump will use more electric."

    Hoping to get a handle on this before I do the solar project.

    ChrisJ
     
  2. Bergy

    Bergy Member Industry Professional Forum Leader

    Chris,

    Residential Delta T should be set up for 10*. It can be higher but you will begin to feel temperature differences from one side of the infloor loop to the other.

    How many GPM flows between the heat pump and the buffer tank and at what Delta T?

    Bergy
     
  3. ChrisJ

    ChrisJ Active Member Forum Leader

    No ports or gauges on the heat pump to buffer tank piping. The pump is a B&G PL-36 1/6 HP with 1" copper pipes, quite a few 90's to get from the tank to the heat pump. Can GPM be figured with that info?

    ChrisJ
     
  4. ChrisJ

    ChrisJ Active Member Forum Leader

    Well this is our 3rd winter. It has been COLD in Rhode Island. Our system used the most KWH's in 24 hours, since I started keeping track daily about 2 years ago, 72 KWH's, plus a little electricity for 2 circlators (taco 007's) that are not wired to the HP meter.

    Last night the EWT was 44*F and LWT was 39*F, so I am very pleased with how the loop is performing. I know it's only mid-winter but the HP was probably running all day yesterday non-stop.

    The indoor humidity dropped below 50% for the first time this winter. I have been keeping an eye on levels for about 9-10 months. I opted not to have the installer put in the HRV he quoted. Originally I wanted a wood stove in the house, installer said I would need the HRV to keep bath fans from sucking the draft out of the wood stove. For the price of the HRV I didn't need a wood stove that bad.

    But now I am thinking I may have to retro fit an HRV or use a de-humidifier during shoulder seasons.

    Chris
     
    Last edited: May 14, 2013
  5. ChrisJ

    ChrisJ Active Member Forum Leader

    Since this past spring I have noticed higher then normal KWH's usage, I have an electric meter that show just HP useage.
    At first I thought it might be a fouled DHW heat exchanger, it was suggested I should be flushing every year with vinegar.

    But during summer cooling the unit ran longer, sometimes second and third stage when it wasn't that hot out.

    Installer suggested sending water out into the drip-loop that was installed above the loop piping. Doing that did lower my EWT but only 1.5- 2*F. Didn't change KWH usage.

    The installer sent a tech today to check refrigerant level. He found oil coming out of the low pressure switch. Part will be ordered, second trip he will recover refrig, install new switch, weigh back in 6.11 lbs. Hopefully all goes well.

    Chris
     
  6. Bergy

    Bergy Member Industry Professional Forum Leader

     
  7. Bergy

    Bergy Member Industry Professional Forum Leader

    Chris,

    The piping between the heat pump and the buffer MUST have P/T ports installed. Without them there is no way of knowing your GPM. The GPM flow needs to match that of the heat pump requirements... 3GPM/Ton, Or 12GPM for your 4 ton unit.
     
  8. ChrisJ

    ChrisJ Active Member Forum Leader

    Yes we should have put some gauges on the piping. The ground loop and the radiant loop (and the DHW loop for that matter) all use the same model pumps, B&G PL-36 1/6th hp. I understand they have different pressure drops but would they be close?

    Radiant was being heated using just the stage 2 compressor which is about 2 1/2 tons.

    Response a year and a half later LOL ;)
     
    Jhwelder likes this.
  9. Bergy

    Bergy Member Industry Professional Forum Leader

    The flows will NOT be the same. You must have the ability to verify flow rates through the system if you wish to troubleshoot the system. If the flow through the source side and load side(s) is not set properly, no amount of service work on the heat pump will be valid.

    Bergy
     
  10. ChrisJ

    ChrisJ Active Member Forum Leader

    See attached diagram from the manufacturer, That's what my plumber and I had to work with. The installer let us plumb it but said very little after it was all done. Now I'm having trouble getting the plumber back to put in shut offs and hose bibs so flushing can be done on DHW loop.

    So I will look in to getting ports, or would combination temp and pressure gauges work? Have them soldered in all at the same time.

    Thanks for your help Bergy.

    Chris
     

    Attached Files:

  11. Bergy

    Bergy Member Industry Professional Forum Leader

    Chris,

    Gauges will not work. No two will display exactly the same pressure or temperature.
    P/T ports are the only way to get accurate information.

    According to your drawing, there is no back-flow preventor or pressure reducing valve on your system. You are asking for, possibly, contaminated water to flow into your home's drinking supply with this set-up. The attached drawing is how it should be plumbed. (unless local codes require otherwise.)

    Bergy
     

    Attached Files:

    Last edited: Sep 19, 2013
  12. ChrisJ

    ChrisJ Active Member Forum Leader

    Yes the drawing from the manufacturer is vague almost useless. Here is a hand drawing (sorry i'm not an artist) of my set up.

    I do have a pressure reducer, back flow preventor. I have temp gauge on radiant supply and temp & pressure gauge on return, so I can at least see what's going on temp wise in the floor.

    Biggest difference I see compared to your drawing is my expansion tank is on the load loop not the radiant loop. The tank is also not just before the pump (pumping away, I think that's what I have read about).Maybe that's part of the reason I am having trouble with air in the radiant loop.

    Chris
     

    Attached Files:

  13. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    Chris,
    Most geo manufacturers expect a few days of training by those who purchase their equipment so the installation instructions are just cliff's notes of all involved.
    They do not feel a particular responsibility to those who do not attend their training
     
  14. ChrisJ

    ChrisJ Active Member Forum Leader

    Thanks Joe,
    That makes perfect sense.
    My Installer probably was not used to or not good at dealing with partial DIY, my plumber was doing the piping.

    Just hoping I don't need a total reconfiguration, add some pete's ports, shut offs and boiler drains.
     
  15. Bergy

    Bergy Member Industry Professional Forum Leader

    Chris,

    I changed my drawing to include boiler drains. Sorry for the omission.

    Bergy
     
  16. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Chris:

    Tell me more about the air issues in the floor loops.

    Mark
     
  17. ChrisJ

    ChrisJ Active Member Forum Leader

    Starting at the begining. Purchased pex and manifolds direct from supplier. We configured the manifolds with a tee in the middle because someday might make 2 zones out of that one.

    Because I didn't know enough to put conduit on pex to protect it, one pipe was hit when the cement was being done and a coupler had to be added. I think some air is stuck in that loop when we purge that zone. There are no shut-offs for each loop.

    When I start-up the radiant in the fall, just turning on the circulator for that zone, I hear the air in the pipes, there is a Taco hy-vent (I think that's what it's called) that lets out some air. The pump runs but takes a while to get to a point where it sound like its just moving water, I can hear little farts of air coming out of the dip tube in the buffer tank.

    I purged it as best as I could last fall, pump ran with no air sound until I left it for a few day without the zone running, then air must have worked it's way out of the loop to the highest point in the piping.


    CIMG5381.JPG Utility rm002.jpg
     
  18. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    The tubing looks like 1/2" CTS pex or pex-al-pex. The manifolds are ok, but could be better.

    A fast fix solution to the air bleeding issue would be to install some ball valves. One for each loop. Then you could power flush one loop at a time. The ball valves could also be used as balancing valves if you could "see" the flow.

    I might consider up-grading the manifold. An idea manifold set would include balancing valves and flow meters.

    Mark
     
  19. ChrisJ

    ChrisJ Active Member Forum Leader

    You are correct on the 1/2" pex-al-pex. I would love to change them over to better 4 loop manifolds with shut offs and flow meters, i've looked at them and prices are not too bad. I agree most economical solution would be small ball valves, on the return manifold? correct?

    Chris
     
  20. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Chris:

    Next time we are East lets get together, I would love to see your project. I have found that DIY types tend to play with the systems. I declared Wednesday, that a project Stephanie and I have been working on to be finished, with the commissioning of the Tekmar 406 House Control. We started that job 6 years ago next month.

    I looked up press in ball valves from the sharkbite folks and verified their availability at the big box store before I typed. With a good pex cutting tool and 1/2" valves you could add the ability to purge one loop at a time for under $100.00 and some water on your feet. Turn off the feed before you cut the pipes. The Ipex compression fittings on your manifold are not easy to find. I might have a few in my storage building.

    That would be the fast cheap fix for getting out any air. Your observations are correct, when you turn off the pump for the loop all the air pools at the high spot.

    When I mentioned the tinkering that seems to happen in these projects I had a manifold upgrade for your system in mind. If you go that way it is time to alter the piping and add air eliminators to the piping. If you need help getting the parts or designing the piping let me know here.

    I am changing IP and will need to change email addresses after twenty years.

    Mark
     

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