Closed loop - efficiency iffy ?

Discussion in 'General Discussions' started by sunnyflies, Mar 16, 2009.

  1. sunnyflies

    sunnyflies Member Forum Leader

    A locally respected well man told me today to stay away from closed loops as they are "much less" efficient than open loops, and, he said they lose efficiency over time. Anybody heard that?

    He said he's replacing a large closed loop system (100 loops) that has been in place for ten years at an aquarium with an open loop system. It's next to a salt water estuary, so the ground water level can not be far from the surface. It's entering temp used to be 65, but is now up to 70, while ground water temps in this area run 55.

    I asked him what size the loops were, as I wondered if they were of too small a diameter, but he didn't know. Nor could he tell me how close together the loops were placed, as I believe that can affect the ground temperature. I should have asked about depth, but I doubt he would have known. He just said emphatically that the place wanted him to put in an open loop system immediately.

    Could it be the original closed loop system was sized wrong?
     
  2. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    zactly?

    along with a short looped cenario you could also add one where the cooling load dominates and over time the field gradually increased in temprature. There are a million other things that could also cause this.
    Blaming it on efficencies is just not one of them.
     
  3. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Sunny

    YES it could, but I know you know better.

    Nothing is free, ask Janice Jopplin.
     
  4. sunnyflies

    sunnyflies Member Forum Leader

    I was at Woodstock and saw Janice Joplin perform.

    Back to those funky soon-to-be-replaced loops. This climate is warmer than New England, but colder than Pa.

    "along with a short looped scenario you could also add one where the cooling load dominates and over time the field gradually increased in temprature. There are a million other things that could also cause this.
    Blaming it on efficencies is just not one of them."

    I am glad to hear you do not think it's the closed loops fault. I am guessing they are placed too close together and are affecting each other.

    The aquarium is built on waterfront property. So, 70 degree entering water temps, right next to tidal cold water that mixes with a small river outlet, doesn't make much sense. Surface waters are downright COLD this time of year. That has to have an affect on the surrounding soil area.
     
  5. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    the load

    Alot of big buildings early on thought that geo was just for air conditioning. They installed supplemental heating that they ran 100% of the time/ big boiler. The heating season may have never been applied to the loop. I was just involved last year with a mcmansion that installed radiant in all the floors run off a boiler. The engineers got busy and came up with some numbers for the geo to run in heating to offset long term heating up of the field.
     
  6. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Size does matter

    Loops can not be over sized. What can be over sized is the amount of money spent of pipe and the labor to bury it in the ground deep enough to do any good.

    Pipe is cheap, labor is not.

    Then add profit.

    If I do a job to customer specs and the system does not work I have no liability so I can give a lower price than if.

    I bid the job to work, I design and install the system, and it does not work then it is my fault, I am liable. Think Credit default swaps.
     
  7. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Open loops are vulnerable to efficiency losses owing to fouling

    There ain't no free lunch.
     
  8. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    BTW

    I thought Jimi was the best show at woodstock.
     
  9. sunnyflies

    sunnyflies Member Forum Leader

     
  10. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Dear Sunny

    I guess it depended on when they played during the trip. Athens Ohio was a very peaceful town in those days.

    Pick a machine. Send me the model number, or a PDF of the engineering reports and I will tell you how much tubing to bury in the yard.

    I am sorry to say I had to think very long and hard to remember Janis's name. I am current on BTUH, however.
     

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