Purge cart reversing

Discussion in 'Geothermal Loops' started by Donald, Feb 4, 2011.

  1. Donald

    Donald New Member

    Hello I just completed Climate Masters accreditation and will be installing my first system (a horizontal loop) in the spring. We discussed flush carts in the class and I watched the video on their website. Neither mentioned the need to reverse the flow but I noticed that most of the carts shown on this site have this ability. My question is is this necessary and when and how would it be used? I am collecting the parts for my cart now so it will be ready when I need it. I am hoping to get it right the first time so any advice would be appreciated. Thanks Donald
  2. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    I do not have a scientific answer, but one born out of common sense and probabilities. Reversing the flow allows turbulance in the oppisite direction, thus reducing the possibility of tin air bubbles being trapped in the ebb side of fittings, or surface tensioned in the pipe somewhere. We allways reverse flow several times while purging and have an excelant record as far as "no call backs".
  3. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    When purging a vertical loop system, the air needs to be pushed to the bottom of the loop (sometimes 400' or 500' deep). If you are purging multiple loops at once, it is possible that the air in some of the loops will not get pushed to the bottom. By reversing the flow, the air, that didn't get pushed down and out, now doesn't have to go down, only out.

    On commercial jobs, we sometimes have to purge 30 loops at once (thanks to the engineers who don't care about how hard they make the job for us).

    When we reverse the flow on a system like that, large amounts of air come out right after we reverse.
  4. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Callous engineers...
  5. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    Sorry Curt:eek::eek:

    I bet you would never do that :D:D
  6. Donald

    Donald New Member

    Thanks for your answers. I was just thinking about the horizontal loops and it appears that the reversing might help there but in a vertical loop it seems like it would be almost necessary. So I will install the reversing valves.
  7. geome

    geome Member Forum Leader

    Does CM require their dealers to go through this process?
    Best wishes for success with geothermal. :)
  8. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    If you are flushing a horizontal slinky loop, be sure and flow one direction long enough to circulate to total length of the loop. Otherwise you will just push the air back and forth in the loop.
  9. Donald

    Donald New Member

    Apparently they do. My supplier will not sell to you with out it. It was taught at their shop by a Climate Master instructor who flew from Seattle to NY for the course. It was two full days followed by a test.
  10. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    All but a few brands require at least a couple days of product training.


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