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using extended headers for floor joist application

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I would like use extended headers in my basement floor joists. I don't see anyone using flow control valves in everything that I've looked up for this setup. If all my loops were equal length that would not be big deal but some of the loops will be greater than the 10% length difference recommended. Is there a way to put individual valve's a each position coming of the header?

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  • hot_rod
    hot_rod Member Posts: 22,476
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    That basically how radiant manifolds can work with adjustable balance/ flow indicators. You can buy stand alone valves, either a plain ball type valve or indicator type balance valves to adjust and confirm flow rates.
    How much outside of the 10% rule of thumb are you considering?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • kylewilliamson
    kylewilliamson Member Posts: 5
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    I was going to have 8 circuits. 6 circuit are at 225 feet using the extended manifold design but I have one area of the home with 316 feet needed so I was going to split that up. I'll try and make a detailed drawing tonight attach it here tomorrow maybe that will help.
  • hot_rod
    hot_rod Member Posts: 22,476
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    Sure you could split the 316 and balance down. Or split the 316 into two 200 footers and no need to balance. Usually you can pack in another 40 feet in a loop. Tighten spacing for example.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • kylewilliamson
    kylewilliamson Member Posts: 5
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    That's a good idea I didn't think of that. Wont that cause the space to be hotter than other ares?
  • hot_rod
    hot_rod Member Posts: 22,476
    edited May 2020
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    Tube under the subfloor? Are you using transfer plates? That extra tube in a joist space to two should not be a problem. Less $$ compared to adding balance valve to all the other longer loops.

    I always tried to optimize the loop lengths to work out of the coil size. So 333' loops or 250' from a 1000' coil for example, or 250' from a 500' coil.

    No reason to end up with a bunch short coil ends. Better to over tube than under tube.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • kylewilliamson
    kylewilliamson Member Posts: 5
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    I worked it out last night so that I have 2 loops at 220. 5 loops at 225 and 1 at 205 so I'll just coil up an extra 15 feet on the last loop correct? Yes I'm using transfer plates and I agree I was trying to avoid spending all this extra money on balance valves. I hadn't thought about being able to leave some coiled in between the joist but it makes perfect sense. Tubing is relatively cheap compared to all the valves and manifolds.
  • hot_rod
    hot_rod Member Posts: 22,476
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    Yep, just suspend or fasten that extra footage in the joist bay, no need to put it in transfer plates
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • kylewilliamson
    kylewilliamson Member Posts: 5
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    Great that's what I'll do thanks so much for the help. My current pumps on my boiler are Taco 1/25 will that be able to handle the 1,768 sq ft? I figured if I kept the loops short it would keep it under the head limit. It says it flows 23 GPM and Max head is 10.