Is it possible II

Discussion in 'Geothermal Loops' started by wigaloi, Jan 15, 2018.

  1. wigaloi

    wigaloi Member

    I've chronicled my long standing geo issues in the "Is it possible" thread started about 5 years ago.

    My initial question was would it make sense to combine my two slinky loop fields, and the general consensus is that for my situation, yes it would.

    Along the way I've redone ductwork and have had several folks out to diagnose and service/"fix" my 2 units.

    Bottom line, I'm ready to combine the loops and the only contractor willing to come in and do it wants $6500.00. He is using my existing flow centers and pumps. He is going to provide some wyes, check valves, balancing valves and labor.

    For the life of me I can't get to that number. A one day job with 2 guys, maybe 500 in materials, some profit and overhead...maybe 2500 tops is all I can see.

    When I asked why so expensive, he simply said..."tying the loops together is not as easy as you think. It's complicated and a lot goes into it. I said what about just getting a new dual circuit flow center, materials would be more, but that should "uncomplicate" things. He said it's still not that simple and that it's a big job.

    If I recall, I don't think I spent $6500 to have 1 of the 4x100' trench with 750' of slinky loop fields installed.

    Any thoughts?

    Both sets of header lines are easily accessible in a clean and dry crawlspace.

    Original thread. https://www.geoexchange.org/forum/threads/is-it-possible.5230/

    Wel server data
    http://www.welserver.com/WEL0991/
     
    Last edited: Jan 16, 2018
  2. mtrentw

    mtrentw Member Industry Professional Forum Leader

    I agree this doesn't seem reasonable. If PE pipes are easily accessible and each field is near the other filed pipes, it would seem you need to add two "Y's" on supply, two "Y's" on return and a big system purge. It wouldn't add any capacity, but it would balance capacity between two heat pumps and two pipe fields.
     
  3. wigaloi

    wigaloi Member

    Thanks for the response Trent. Yes, the ground loop for the downstairs unit is laid out in the back yard and comes through the foundation from the back of the house into the crawlspace. The ground loop for the upstairs unit is laid out in the front yard and enters through the foundation at the front of the house. The 2 sets of header pipes literally come with in 10 feet of each other so the actual physical connections would be logistically easy.

    Any thoughts on ditching my current 2 pump flow centers for a 2 circuit variable speed zero pressure flow center?

    It's funny sometimes how guys are so short sighted. They see your set up and want to try to make all of their profit on one j0b. They don't think about future business through referrals and other projects that one might have going on.
     
  4. mtrentw

    mtrentw Member Industry Professional Forum Leader

    As an engineer, I understand piping and flow. As a system owner and DIYer, I have a good handle on my own system. I don't have much knowledge on different flow center options and energy impacts. I expect one of the pros on the site who install systems routinely will chime in with opinions
     
  5. wigaloi

    wigaloi Member

    Thanks for replying again Trent. Hopefully Doc, urthbuoy, waterpirate et al will chime in over the weekend.
     
  6. ChrisJ

    ChrisJ Active Member Forum Leader

    The heat pumps look to be in tight quarters. where is the crawl space in relation to the heat pumps? And heat pumps to each other.

    I have been watching your WEL site, running constantly, switching stage 1 to stage 2 and back. 16*-18* LWT, 24*-25* EWT. Yet it is in the mid to high 40*'s outside.
     
  7. wigaloi

    wigaloi Member

    @ChrisJ There is enough room to maneuver. The downstairs heat pump has changed some...I had an hvac company come out and enlarge the main trunk supply duct for zone 1 under the house and increase the size of the return plenum.

    With regard to proximity...The downstairs heat pump sits on the main floor, so it's directly above the crawlspace. The heat pump that serves upstairs is on the 2nd floor and the header pipe travels up a chase to get there.
    If it turns out that a non-pressurized 2 circuit flow center (http://geo-flo.com/flowcenters/?Residential_Products/NP_Dual_Circuit_Non-Pressurized) is the best option, there is plenty of room in the downstairs equipment room for it to fit and the necessary holes drilled in the subfloor to tie in to the header pipes going up stairs to the h.p. up and the to the ground loop/s.

    And yes, in the winter time, the downstairs h.p. typically runs 15-24 hours per day in stage one and anywhere from 3-20 hours in stage 2. the upstairs h.p. hasn't run for probably 3 weeks.
     
  8. wigaloi

    wigaloi Member

    Any feedback from the pro's?
     

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