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Thermostat

Charlie_9
Charlie_9 Member Posts: 4
in Radiant Heating
I've installed a new hydronic heating system which includes both hydronic baseboards on the second floor and radiant heat in several rooms that are adjacent to each other on the first floor. These rooms also have supplemental hydronic baseboards. The floors are 3/4" oak over plywood, with the Pex-al-Pex radiant tubing attached to the top edges of the joists. Looking for a recommendation for a thermostat that will control both air and floor temperature, incorporating a floor sensor.

Comments

  • STEVEusaPA
    STEVEusaPA Member Posts: 6,506
    Well Tekmar makes a t-stat for that, but what kind of boiler control are you using?
    steve
  • Charlie_9
    Charlie_9 Member Posts: 4
    I have a Navien tankless boiler with Taco controls
  • Rich_49
    Rich_49 Member Posts: 2,766
    Could you take a picture of the tubing placement or describe a bit better where the tubing is attached ? One pass per joist bay or two ?

    How is the baseboard / radiant arrangement piped ? Is the Navien a combi or is it strictly a boiler , what is model number ?

    Pictures of the boiler and near piping please . Yes it does make a difference
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    732-751-1560
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    Charlie said:

    I've installed a new hydronic heating system which includes both hydronic baseboards on the second floor and radiant heat in several rooms that are adjacent to each other on the first floor. These rooms also have supplemental hydronic baseboards. The floors are 3/4" oak over plywood, with the Pex-al-Pex radiant tubing attached to the top edges of the joists. Looking for a recommendation for a thermostat that will control both air and floor temperature, incorporating a floor sensor.

    Do you still have access to the tubing from below? I hope so, because fastening to the sides of the floors joist is not an approved method of installation, and there's not a control logic on the market that can straighten that problem out.

    Tubing should be stapled 8" on center in the joist bays, and fastened as often as possible to ensure good tube to subfloor contact.

    Ideally, the tubing should be installed in good quality extruded aluminum heat transmission plates.

    If access is not available, the best you can expect is floor conditioning, where the floors are not ice cold...

    Good insulation is also a critical detail commonly overlooked on these joist bay installations. I'd require a minimum R 15 insulation in tis situation, and NO BUBBLE FOIL BUBBLE crap. Junk science.

    ME
    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
    Ironman
  • Ironman
    Ironman Member Posts: 7,375
    Charlie said:

    The floors are 3/4" oak over plywood, with the Pex-al-Pex radiant tubing attached to the top edges of the joists. Looking for a recommendation for a thermostat that will control both air and floor temperature, incorporating a floor sensor.

    You won't get 1/2 the btu output that you could with extruded plates installed.

    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    Nice chart Bob. Where'd you find that gem? (I see who did it, wondering if there is anything else to accompany the chart)

    ME
    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Ironman
    Ironman Member Posts: 7,375
    It's from Rehau's training manual and summarizes the results of a study done by VA Tech's engineering department.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    Mark Eatherton
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    Cool, thanks.

    ME
    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Ironman
    Ironman Member Posts: 7,375
    Mark, I'm sure you can find the entire study somewhere on line, but coming from engineering it's overloaded with verbage.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • SWEI
    SWEI Member Posts: 7,356
    I emailed Mark a PDF of the study.
    IronmanMark Eatherton

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