Flat or standing slinky

Discussion in 'Geothermal Loops' started by bjl, Jun 28, 2015.

  1. bjl

    bjl Member

    I had posted awhile back on my new construction diy geo system, and you guy's did not dissapoint. It has been awhile but I am building almost the whole house by myself. My neibors think I'm nuts. Well anyway, doc says, 8 - 3' slinkies 600' long in a 75' trench. One of my questions was to put the slinky vertical against each trench wall to minimize digging. Doc says doable but would have to fasten to the wall which require getting in the 10' deep trench, yeah, i'm not going to do that. The first question would be, is it less efficient to place them vertical than laying them flat?
    I had an idea after I dug my septic tank hole. This hole was 7' deep and 6' diameter. It filled up with about 1' of water in an hour. If I was to use my 12" bucket and dig down as deep as the mini can go, aprox. 11', construct a semi rigid frame from pvc to hold the pipe and lower this vertical in the trench, and then backfill with loose riversand till the pipes are covered then backfill with the excavated dirt. Riversand is very cheap here in southern louisiana and the extra dirt can be used for fill elsewhere. Would the sand allow the water table to move better around the loop field?

    Thanks for all of the information.
  2. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    A loop in saturated sand offers excellent heat transfer.
  3. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    I cannot detect any difference in heat transfer of a standing slinky versus a laid flat one, assuming that the average depth is the same.

    The only issue is a practical one, make sure Verticals do not kink during backfill.
  4. bjl

    bjl Member

    Thanks doc and palace. That is why I was going to use river sand. It's very loose aND will encase the loops very well, and the pvc frame will keep the loops from clasping on itself. It's a little more work, but a lot less digging, and I do not want to get in any trench.

    What wall thickness pipe should I use?
  5. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    if you are using 1" pipe, I think your only choice is DR 11. I have vertical slinkies on my house and they work fine.

Share This Page