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Radiator Vent Considerations

As part of our water leak/energy use issues on other threads, the last radiator on the long line has been noisy or too cold for the tennants. Packing the supply valve nut may have solved the noise problem since the stem was very lose (we'll see as the weeks go by and they report back to us).

For radiator vents, is a smaller vent generally better for rooms that get too hot to slow down the new steam entering the rad, and does the rad size in the room (large or smaller) happen to matter if too hot anyway? We'd like to just reduce the vent speeds in the hotter 2nd floor rooms to suit the tennants, or increase the vent speeds in the colder 1st floor rooms. Are other considerations needed to be taken into account, or can this be done as simply as it sounds above?


  • Jamie Hall
    Jamie Hall Member Posts: 22,912
    It's just as simple as it sounds. And just as fiddly. You may get it right on the first try, then again you may not -- particularly as changing one radiator may affect other radiators, particularly if they are on the same riser.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • cubicacres
    cubicacres Member Posts: 358
    We're thinking about swapping the hoffman 1a vari-vent with a thermostatic vent for our tennant who wants the bedroom rad off completley during the night. Any suggestions on which TRVs, or how they're different? I suppose some have larger vents, or different technology?

    For some reason turning the hoffman vent upside down worked to keep the rad off in the dining room but didn't stop the rad in the bedroom.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    Turning the vent upside down, and still having a hot radiator indicates high pressure to me. How many ounces are you seeing on your gauge both during steaming, and backpressure of the venting phase?--NBC
  • cubicacres
    cubicacres Member Posts: 358
    Our pressuretroll gauge has a 0-30psi range and never seems to move off of 0 psi. I think the cut-in is at .5 or 1 psi with a differential of 1, so a cut-out of 1.5 or 2 psi last time we checked.

    Can we simply buy a 0-3 psi gauge, attatch it with a pigtail & some short pipe segments and watch how we're doing? If we have higher pressure and it goes above 3 psi, does it risk breaking the 0-3 psi gauge? How does higher pressure occur in a lower pressure system like ours?
  • Steamhead
    Steamhead Member Posts: 16,723

    Turning the vent upside down, and still having a hot radiator indicates high pressure to me.

    I would say it means the vent is leaking.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service