Heat extraction, pond dimension, Lima-1

Discussion in 'Surface Water Loops' started by thermopat, Apr 13, 2012.

  1. thermopat

    thermopat New Member

    Hello

    Does someone knows how to determine the seize & volume of water required in a pond to ensure regeneration of extracted heat in winter conditions?

    If a pond is too small and we use a compact heat exchanger like Lima-1, does global pond temperature could cool until 32*F and then freeze completely?


    Patrick
    Thermopompes Saguenay
    Chicoutimi (QC) Canada
     
  2. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    Yes, you could freeze the pond.
     
  3. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Useing an exchanger that is compact in a pond that is potentially to small would not be adviseable.. I thought I read somewhere, prolly here that 1 acre in size is the bare minimum for pond size, and even then more engineering is required.
    Eric
     
  4. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    In my AO half acre is minimum at 8' deep.
    Depth matters as much as surface area.
     
  5. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    Let say for a 6 ton loopfield we use an area of 70x100 ft (0.16 acres) for heat exchange (slinky), why do we think that a much larger area is required for a pond, where a superior medium (water) connects the pipes to warmer ground (bottom of pond)? I have used 0.2 acres ponds 6ft deep, which work great. The key is to spread the pipe out similar to a horizontal slinky.
     
  6. thermopat

    thermopat New Member

    Docjenser I think your logic is good. If I have a minimum of 8' deep and enough area for laying my slinky then why it would not work?

    I think I will use 0.2 acres per 6 tons ratio.


    AMI Contracting what is "AO" ? Thank you
     
  7. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    True, less will do. I quoted manufacturer minimum requirement vs practical minimum. I would caution OP to know who they are dealing with if manufacturer minimums aren't complied with.
     
  8. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    The OP is talking about using a very compact heat exchanger that I have very serious doubts about in a pond where there is no current.
     
  9. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    I was thinking the same. Looking at the product, there are only a few openings where water can exchange. How would you prevent it from freezing up? At the end we are sending out fluids in the pipes at sub freezing temps.

    In order to have a 6 ton capacity as claimed, and to support lets say 40.000 BTU/h heat extraction, and you assume that it is exposed to 39 degree water at the bottom of the pond, and the inside of the "ball" cannot be below 32 F, you need a minimum of 11.5 gallons per minute flow through the openings, under all the circumstances, pretty much through stratification inside the ball only. I don't see that happening.......
     
  10. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader

    Water Temperature

    Cold (liquid) water gets to around 35F around here.
     
  11. thermopat

    thermopat New Member

    I would be worried about remains under water that could choke the vent ports or obstruct inside the exchanger.

    See what they say on their web site in FAQ:

    "When operating under load (heating or cooling), as much 20 gpm (US) of water moves through the vent ports located top and bottom of the LIMA-1 shell flushing the core with “energy rich” water."
     
  12. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    Sounds like baloney to me:D:D
     
  13. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    20 gpm flow? Powered by what? This ball will likely be an ice ball in no time.
     

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