Ontario 5 ton Geo running 24/7

Discussion in 'Maintenance and Troubleshooting' started by Maurice Sabourin, Oct 21, 2015.

  1. mrrxtech

    mrrxtech Member

    Maurice,
    Delta Ps & Delta Ts are taken at the Unit loop Inlet & Outlet for determining performance with the air side taken the same way, at the Unit air inlet and outlet.

    Looking back at the pictures of the folks building your pond heat exchanger, I'm betting they pulled the pipe off of the roll rather than rolling the entire roll across your yard and leaving straight pipe on the ground with no tendancy to kink.
    The pipe in the trench must have been rolled into the trench since the pipe appears to be straight for that very short distance showing.
     
    Last edited: Apr 14, 2016
  2. Maurice Sabourin

    Maurice Sabourin Newbie but learning quicly...

    UPDATE... UPDATE

    The installer will not supply the information on the loop I asked for, he says he gave it to me when he installed the unit...
    I don't think he as any idea of what his men did installed in the pond.

    The last couple of weeks the flow centers have started to make noise and the motor are warm to the touch, sounds like air as been introduced in the loop again, even after I had the loop flushed of air less than six months ago.

    we have had some cold nights lately and I noticed the heat pump has been shutting off normaly.
    So today I took some measurements

    Outside temp is 30F with a slight wind chill.
    I called for 71F and made it kick into stage 2, Aux heat is off at the breaker.

    Y2 26 VAC
    Amp at the compressor is 13.45A
    Supply Air is 92.4F it was less the 88F all winter
    Return Air 68/9F was around 67F in winter.

    Delta T 6.1F at the Petes ports.
    Delta P is only 2lbs at the Petes ports

    I have bled the air I could from the flow centers, but it does not do much... The noise comes right back and the pressure drops to near zero.

    My thinking is this:

    the lines between the loop and the house gets pinched during the winter, and when the soil thaws, the loop get its full flow back.
    Walking around the pound, I saw one of the pipes near the surface of the water as well...
     
  3. mrrxtech

    mrrxtech Member

    Maurice,
    Your Delta T between Return air and Supply air should be closer to 27 to 30 degrees based on my experience with 2 heat pumps. Your Delta P is low as well. Use the manual for the Unit to look up required flow per Ton based on Delta P. I included a link for your Units manuals in an earlier post.

    The pond Heat Exchanger needs to be weighted and sunk to the bottom of the pond again since summer cooling will heat the surface water and reduce your heat transfer capability and efficiency .

    You probably have a leak in your loop, since there is noise in the flow center again due to air. I forgot how the loop was put together. If it was welded then you probably have leaks at the Flow Centers, or any hose clamped fittings. The welds don't leak if they are performed correctly.

    The Pinched lines that uncramp in the spring, is it possible that your supply and return lines were in the Pond Ice being pinched. If not, then I doubt the lines were pinched by frozen ground. Was your antifreeze determined to be acceptable for your area in Canada?

    Make yourself a flow cart for less than $200 and re-flush the system rather than paying for another professional flush.

    If you need any geothermal parts, I believe Mark can supply you with the items you need.

    Let me know if you only want to talk to Doc. I'll understand. I once had my older brother steal my babysitting job as a kid, I'm over having my feelings hurt, including being berated for not having enough geothermal experience.

    As long as you get good advice it doesn't matter who the provider is.
     
  4. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    I put loops in ponds.
     
  5. mrrxtech

    mrrxtech Member

    That there pond install job is a Beaut Mark.
     
  6. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    Rob, No issue with you chiming in here, as long as you are not off in your statements. Sorry to hear about what your brother did to you when you were a kid...

    Maurice, what was your EWT? Indeed your flow is low, indicating only 8-9 gpm if this was the 5 ton unit, your loop pressure drop even with more power. Zero pressure drop assumes no flow.
     
  7. Maurice Sabourin

    Maurice Sabourin Newbie but learning quicly...

    Yes it was the five ton unit.
    Thes EWT was 49.8f. I had to look ip the definition of EWT
    the other side was 43.7f

    The pressures used to be a lot more. It just keeps dropping.
    sometimes the tecks would add water from the hot water tap to bump it up.


    is the air in the loop a factor for the pressure drop?
     
  8. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    Tough to say, but pressure fluctuations between summer and winter are normal, and they can go along with air bubbles forming in the loops due to changes in pressure. It is actually gases in the water which can actually fall out. That does not mean you have a leak for sure.

    That is the reason why self purging non-pressurized flow centers were invented. They are called "call back eliminator" for that reason, since you don't have o come back and rep urge them.

    However, that does not mean that you cannot have a leak elsewhere.

    But since your loop design, pressure drop, pumping design and power etc are quiet questionable I would take a step back and ask wether you should redo this right. There are many worms crawling out of your can right now.

    1) You don't have the correct flow because your pressure drop is too high for your loop field
    2) Because your pressure drop is too high, your contractor installed larger highly inefficient pumps.
    3) The pumps fight each other when they are both running, stealing flow from each other.
    4) Your heat pump does not run at full capacity. There might be something wrong with your refrigerant circuit as well.
     
    Last edited: May 2, 2016
  9. mrrxtech

    mrrxtech Member

    Maurice,
    Putting myself in your situation, here is what I would do:
    Make some assumptions - 1) Your Geothermal Units are relatively new and have no Freon leaks. You can verify that later when the other problems are fixed. 2) Your loop needs an air removal method and auto makeup method. 3) You'll need to add antifreeze and water when the devices are installed.

    Add Auto Air Removal Devices:
    Find the high point inlet and outlet lines, which from your pictures appears is above the 5 Ton Flow Center. Add an auto air removal float valve on each line. See the $9 Watts Float Valves ebay 371469352910 .

    Add Auto Makeup Device:
    Install a 4 gallon pressure tank with bladder ( ebay: 281907742914 ), similar to a well water pressure tank, but they are made for hot water tanks to prevent noises and allow for surge volumes as the water heats up. Install it anywhere on the loop.

    Fill, Pressurize and Add Antifreeze as Required:
    Pressurize the loop using a your water source, but add a clear filter body ( ebay 282016419846 ) in series that can be prefilled with pure antifreeze. You can put food coloring in the antifreeze if you want to see when the antifreeze has been flushed into the loop. Flush antifreeze until the system is pressurized, or the loop antifreeze is at a satisfactory concentration to prevent freezing. Continue filling with water until the system is pressurized. Pick a pressure such as 10 lbs, as a starting point.

    The system may not remain pressurized at first due to air being vented out by the Auto Air Removal Devices. It may take a while to reach a stable pressure. Look for leaks as you pressurize.

    You can pick another method for air removal and water makeup but they may be expensive: ebay Expansion Tank & Flow Center: 172074885355 ; Water Return Volume Flow Center: 231074786834

    You can purchase the Flush Cart Swimming Pool Pump later and flush your system if a major leak develops and is repaired.
     
  10. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    The fact that he measures 8-9 gpm flow and has a 6.1 F delta T suggests that his heat extraction is off. This leaves 2 possibilities, either there is something wrong with his refrigerant circuit, or there is something wrong with his refrigerant circuit.

    Indeed the loop needs a way to remove air. This appears to be another case for non pressurized flow centers, with easy access, no pressure fluctuations, and automatic purging.
    However, no system should need auto makeup for water.
    Maurice has additional issues with high pressure drop, and high pumping power, and pumping/loop design.
    He needs to consider to not only bandaid his current situation, but find a solution which ensures long term maintenance free performance.
     
  11. mrrxtech

    mrrxtech Member

    Doc,
    This flow center was designed with a pressure tank which makes up to the system as the loop volume contracts and allows expansion volume as the loop water expands. This is what I mean by automatic makeup. You can fill the tank and let it return water to the loop as the air is removed.
    ebay Expansion Tank & Flow Center: 172074885355

    Maurice's system worked fine for the first year it was installed before it started to fail. Unless a Technician caused a Freon system problem, I doubt that a Heat Pump would fail this soon on the Freon side. Some units have been shipped with a bad expansion valve as one owner told me about, but that problem shows up the day the unit is started up.

    With the number of problems on the loop side at present, the probability of a Freon side problem is low.
     
  12. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    First of all, the pressure fluctuations do not come from the expansion and contraction of the water, which is minimal, but from the contraction and expansion of the HDPE pipe around it. Summer time, A/C season, warmer loops means loss of pressure due to the expansion of the pipe. In the heating season in the winter pressures increase due to contrition of the pipe.
    You should also not make statements because a single customer told you so. Indeed, Maurice's problem occurred after running fine for 2 years, suggesting that something changed in the 3rd year. Expansion valves can fail after years of running, the climate master issue in the w-w pumps is a reminder to many installers.

    If the heat extraction is off, there is only one global issue which can cause this: something within the refrigeration circuit.
     
    Deuce likes this.
  13. Maurice Sabourin

    Maurice Sabourin Newbie but learning quicly...

    Hi.
    I will have to take all these issues one at a time... the first priority is bringing the heat extraction to the level it was before the problem started.
    Most of the other issues with the system I can install and fix myself. The only thing I cant do myself "at this time" is check the refrigerant level or the refrigeration circuit...

    I need to bring in a "new" technician to try to fix the main problem witch is bringing the system back to its original performance level.

    Are the pressure drop, the possible leak, flow centers issues and bad overall design a barrier in fixing the original problem?

    In other words... What do I need to do before I call the technician in to diagnose and fix the loss of 11 degrees F of heat generation.

    Thank you everyone.
     
  14. mrrxtech

    mrrxtech Member

    Maurice,
    Figure out a way to sink your pond heat exchanger to the bottom of the pond. Call a friend or neighbor to help, or use a professional if you can't do it safely with a neighbor.

    I would find a vent point to use for venting air and add water to the loop while venting. You can take a lead off to the compressor at the contactor load side to prevent the compressor from running while filling & venting with the loop pumps. Open the 220 vac breaker or disconnect while removing the lead from the contactor for safety.

    The loop will have less antifreeze due to adding water, but the loop temperature shouldn't go into the 20s this time of year.

    Purchase the Watts auto vents which you can use on the high point line by having a local machinist drill & tap a 1/8 th inch threaded hole into double bayonet brass fitting, or 90 degree elbow bayonet fitting, that fits your loop Inside Diameter. Screw the 1/8 inch Watts float valve/vent into the modified fitting, then you can cut the loop and insert the double bayonet fitting & clamp with Stainless Steel hose clamps. I'll take pictures of the brass fitting or find one on ebay for you.

    This action should improve your delta T and flow so the unit performance will improve.

    Later you can check the antifreeze level in your loop and add antifreeze. Also the 4 gallon bladder tank can be added for next heating season. Your system will work fine through the summer while gathering the parts, like the bladder tank and any other changes you wanted to make to the loop design.

    The goal is to start recovering your losses. It won't happen if you don't take action on your own and get the confidence you need to solve your own problems.
    Make a plan, focus on it until the actions are completed then evaluate what you have and go from there.

    Remember, your system was working fine when installed, you have a floating heat exchanger in the pond and air in the system. Fix those 2 issues and go from there. Two problems are hard to diagnose, three problems at the same time is a very low probability, so stop looking for a 3rd problem until you fix the two problems you know that you have.

    .
     
  15. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    None of the above should be an issue to check and fix your refrigerant circuit issues. A heat pump needs 2 things to stay happy from the loop: 1) A minimum amount of water flow 2) at a certain temperature.
    You have OK flow if only one heat pump is running, and your temps are of water coming in are ok. Nothing which would explain or cause the lack of heat extracted out of the water....the only thing is the refrigerant circuit.
     
  16. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    May be you can elude to everyone here how sinking the heat exchanger and putting a vent in will improve the delta T on the source side in a system?

    The EWT was absolutely fine when tested, and the flow was low, but still tolerable. Yes, some loops surface up and should be sank again, but given the EWTs were normal and the flow was 8-9 gpm, those are not reasons for capacity loss.
     
  17. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    My thinking is the floating pipe contains air and therefore stops or slows the flow.
     
  18. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    Sure, if a loop is air locked your flow can slow down. But with less flow your delta T goes up, not down. Your heat extraction by the heat pump does not change when one of the loop circuits is air locked....
     
  19. mrrxtech

    mrrxtech Member

    The Heat Exchanger is floating in the pond per Maurice. It's time to sink it to the bottom of the pond so the pond doesn't heat up on the surface, while cooling during the summer.

    Maurice said the loop circulating pumps were noisy and heating up as if they are air bound. Venting and filling would eliminate the air.

    The Delta T Maurice spoke of was Return Air vs Supply Air while heating, which was around 20 degrees. If the loop was working correctly the Delta T would be closer to 30 degrees when heating.
     
  20. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    I am not sure how to explain this to you any further, but the delta T on the air side has very little to do with what happens on the source side.

    If he has indeed air in the loop to the extend that there is no flow because both pumps are air bound, the heat pump will go into lockdown immediately. A 35-40% lack of capacity is not a matter of a few gpm lesser flow, the compressor would simply extract more heat out of lesser water flowing through the heat exchanger.

    And the pond will not heat up on the surface because a few loops surfacing up, the sun will do that for them. If you cut down the flow for a 5 ton unit in half, you loose about 7-8% capacity due to much colder leaving the heat pump if your flow goes from 16 to 8 gpm. You don't loose 40% like he does. In the same moment his delta T would almost double, which it does not do either. His flow is only between 8-9 gpm, so his delta T should be 10F on the source side, but he has only 6.1 F delta T, less if the 2 ton is running and steals further flow.

    Having only 6.1 delta T with 8-9 gpm flow tells you that his refrigerant circuit does not take the correct amount of heat out of the water, that is why the delta T on the air side is only 20F instead of 30F.

    Yes, the loop should be free of air and on the bottom of the pond, but that does not cause a lack of heat extraction and therefore a lack of capacity as Maurice measures it here!
     

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