Flush Cart Question

Discussion in 'Geothermal Loops' started by climate changer, Jul 4, 2010.

  1. climate changer

    climate changer New Member

    The company I work for has started selling geothermal and we have only done one job so far. We were able to borrow a flush cart from the dealer ( Geo smart ) when we did the install. That was about a year ago and we have no done another one since. I also built a house last summer and installed the ground loops during construction. I have now installed the heat pump ( installed gas furnace originally and have now retro-fitted for eco-energy rebate). The problem is I do not have a flush cart and my boss doesn't want to buy or build one because were not selling enough.

    I was wondering, Can I rig something up with a 1/2 hp submersible well pump? We have a few lying around the shop. This would only be a one time deal.

    I have 3 loops, 600 ft each of 3/4 poly plus 75 ft of 1" 1/4 from the house to the loops.

    Any suggestions on how I could make this work?
     
  2. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    solution

    It is all about the flow rate and head pressure to get your scouring velocity. After you come up with your friction loss to meet that target, the rest is up to your creative side. It can be as simple as a keg cooling barrel full of water with a ditch pump from the rental store. Big plastic barrels or trash cans also work. As a sidenote a submersible may work for you, but it relies on ground water temp for cooling the motor, also flow past the motor in a defined space. I used to use one to pump out my fish pond in the summer, it would only run for about fifteen minutes before going out on heat overload, when it cooled enough you got another fifteen minutes. That pump is dead now.
     
  3. climate changer

    climate changer New Member

    More questions

    Thanks for the reply. I never thought about motor cooling and defined flow around it. It amazes me the knowledge you find on this site.
    Looking through the classified I see someone selling a 4hp hot tub pump for $200
    Do you think that would work pulling from a trash can and a valve in there to dead head?
     
  4. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    will it work?

    To be sure you need to do the math on your loop field and compare to the pump curve for any given pump. For a swag, pool pumps are often used on commercially built purge carts and some even come with an atatched strainer to sweeten the deal.
    If I were you I would be leaning toward a non pressureised system as your flushing is going to be a one off event. With the non pressurised tank in place even if your purge efforts are a little off, it will be more foregiving and try to work out any air bubbles rather than locking out.
     

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