Directional drilling for vertical loops

Discussion in 'Geothermal Loops' started by bob allen, Jul 3, 2016.

  1. bob allen

    bob allen New Member

    I talked to a dealer/installer a couple of years ago and now can't locate him. He said they use a single well site with multiple directional drilling for installing closed loop vertical systems. I have plenty of land but just about all of it is under an oak hickory forest and I want to clear as little land as possible. I live in Northwest Arkansas and the installer is from that area also. I have an air exchange heat pump but want to replace it.
     
  2. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Vortizontal drilling is gaining traction and is a proven winner. Any directional driller can pull it off with some coaching from the hvac contractor as to what is needed and how.
    Eric
     
  3. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    One never learns by talking.

    Thanks Eric.

    I knew about the Horizontal guys.

    Mark
     
  4. arkie6

    arkie6 Active Member Forum Leader

    Bob, don't you live up around Dover? I live near Russellville and had a geo well driller out of Oklahoma (near Ft. Smith) install my geothermal wells. 3 wells 225' deep, 20' apart, 20' from the house, 4"diameter using a rotary drill rig. $7/ft included drilling, installing the pipe, and grouting. I purchased the geo loop pipe at Sander's Supply in Russellville. I think you will be hard pressed to beat that price in this area.
     
  5. bob allen

    bob allen New Member

    Thanks guys. Arkie6, yes I am up north of dover in bullfrog valley. What size is your heat pump system? and is yours closed loop? did you have a contractor do the install?
     
  6. arkie6

    arkie6 Active Member Forum Leader

    Mine is a 3 ton 2-stage Climatemaster TE30 unit with built in variable speed loop pump. My heat load/gain calcs came in just under 3 ton at 30K-32K BTU. Closed loop. I'm doing the install myself (still in progress). I just hired the geo well driller to dig my wells.

    I used Centennial Plastics Earth Loops 3/4"x510' (255' + U bend + 255') for my well loops. Sanders carries these or they did when I bought mine.

    I used the Climatemaster Geodesigner software (free download) and Pressure Drop Calculator software to design my loops. In our area, summer cooling is the limiting factor on ground temperatures. I designed my loop to maintain <90F loop temperature in the summer. With this same loop and load, my minimum winter loop temperature should be >45F so I don't need anti-freeze in the loops. But note that there are a lot of variables when it comes to designing a loop such as what you hit when drilling that well (sandstone? shale? water?) and the thermal conductivity of the grout. You have to make assumptions on much of this and that gets input into the Geodesigner software. Fortunately, I had a water well dug previously, so I had a good idea what I was dealing with down to 100' (30' red clay over saturated shale with the water table at 10'-15' below the surface). We hit the same material and water levels on the geo wells also. My geo wells actually ended up around 240' deep since the drilling was easy in that saturated shale and the drill stems used were 20' sections, so the driller just drilled to the end of that last stem. We ended up with ~235' of vertical pipe in the ground.
     

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