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Controlling radiant heat in greenhouse

I have a customer building a home with a greenhouse attached.They want to heat with radiant, first time doing radiant in a greenhouse for me. Anyone have any experience with this? I’m concerned about lag and overshoot being an issue in a space with that large a load and that much solar gain. Located in the northeast, looking for any insight from someone with experience in this as far as best way to control it design temps, etc. floor will be a slab. Any insight/suggestions are appreciated.


  • unclejohnunclejohn Posts: 1,456Member
    I'm not gonna be much help but those are will need things like square foot and how many outside walls and such.
  • ZmanZman Posts: 5,545Member
    Posting more details will help.
    You are going to want to store as much of your daytime energy surplus as possible. Solar HW panels of some sort would help lower day time temps and store the energy in the slab.
    The key to preventing overshoot is to manage your slab temps.

    Sounds like an interesting project. You will find plenty of help here.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • hot_rodhot_rod Posts: 12,589Member
    I've never been able to make that pencil out. If the greenhouse is all or lots of glass you don't usually have enough floor area to supply enough energy.

    The greenhouses I have worked around had unit heaters with the radiant.

    Another option is root zone heating. I did one job that just the elevated boxes that the plants were in got heated. Sort of like a raised bed system inside.
    It used a dual rubber hose tube, similar to the early solar roll or Heatway TwinTran.

    It was a package system from a greenhouse manufacturer in Ohio. It had hydronic unit heaters as back up and the whole thing was powered by a large OWF outdoor wood furnace.

    I think the type of plants may have something to do with the amount of heat also.

    Rutgers has been a leader in greenhouse research and clever ideas, maybe check their sit
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
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