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Single Loop with Diverter Tees

drosner Member Posts: 35
hi - i'm adding to an existing hot water heating zone with several new baseboards. I want to control each baseboard with a TRV. After much research I believe the best way is to create a single loop for the zone and then use diverter tees (monoflows) at the supply and return of each baseboard to connect to the main loop. That way I can shut down any of the individual baseboards without impacting the others. I've included a basic picture that also shows the baseboard lengths and required BTUs for each room.

Is this the right way to go for this? If so how do I determine if I need a diverter at both supply and return? Do i have to worry about the distance between the supply and return tees?


  • Ironman
    Ironman Member Posts: 6,875
    Since I'm not aware of any TRVs that also have a bypass, I'd have to say no. You can't shut off flow in a Monoflo system... Unless you can find a TRV that has a bypass.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • drosner
    drosner Member Posts: 35
    I was thinking the TRV connects right to the side of the baseboard and is fed by a section of pipe from the main loop. I would only be shutting off flow to a single radiator and never the main loop.

    Is that not correct?
  • Ironman
    Ironman Member Posts: 6,875
    You can't shut off flow to the rad's in a monoflo system without adding too much head that will effect the flow in the main.

    I would recommend that you look at doing a homerun/ manifold system with a delta P ECM circulator if you want to use to TRVs.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    EBEBRATT-Ed Member Posts: 12,015
    @Ironman is correct
  • newagedawn
    newagedawn Member Posts: 586
    keep the tee's within 6 inches
    "The bitter taste of a poor install lasts far longer than the JOY of the lowest price"
  • Henry
    Henry Member Posts: 995
    You don't need two monoflow Ts if feeding from below. I have seen some installs of TRV on a monoflow system. It is not one of the best ideas.
  • cutter
    cutter Member Posts: 282
    Listen to Ironman, I don't know if he mentioned a 2 pipe direct return or a two pipe reverse return. Listen to the pros and do the job right. Just my two cent's
  • drosner
    drosner Member Posts: 35
    I've been doing some more research including this site and some are saying it's one way to do it but can go wrong if the trv and rad add too much resistance then you don't get flow and it appears like an air lock problem.

    A 2 pipe rerun might be cost prohibited and I'm now considering only adding trv to 2 of the long rads. On one of the dan H articles he suggests doing a 1/2" by pass to do what I'm attempting to do. Any thoughts on this approach?
  • unclejohn
    unclejohn Member Posts: 1,757
    You can run all that in 1/2' copper. And the 2, 3 and 4 footer in 3/8".
  • Paul48
    Paul48 Member Posts: 4,469

    You could use a 560 series zone valve. Just a thought....