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The Importance of Air Venting in Steam Systems

HeatingHelp
HeatingHelp Administrator Posts: 680
edited December 2023 in THE MAIN WALL
imageThe Importance of Air Venting in Steam Systems

Where there is air, steam will not go.

Read the full story here

bburdIronman

Comments

  • dyoung9121
    dyoung9121 Member Posts: 24
    Should I remove the vacuum breakers on my 2 pipe supply main and replace with main vents. The main does have a vent at the end but not sure it works
  • CLamb
    CLamb Member Posts: 325
    Very well written.
  • johnshanahan
    johnshanahan Member Posts: 3
    Our main air vent was plugged by a professional some years back. I just removed the plug before thanksgiving and installed a Gorton #1 main air vent. A radiator towards the end of the main that hadn’t heated in years came back to life. Possibly every story you’ve told here, on your podcast, and in “The Lost Art of Steam Heating” about what can go wrong with a system happened in our building. With your knowledge and after months of working on the problems in units and in the boiler room I’m now just a few more trap rebuilds and a few trap installations away from a well working system. Thank you. I’ve enjoyed the journey. Our HOA is enjoying and will enjoy the benefits, including the lower fuel bills!
    Erin Holohan HaskellIronman
  • guzzinerd
    guzzinerd Member Posts: 282
    johnshanahan said:
    Our main air vent was plugged by a professional some years back. I just removed the plug before thanksgiving and installed a Gorton #1 main air vent. A radiator towards the end of the main that hadn’t heated in years came back to life. Possibly every story you’ve told here, on your podcast, and in “The Lost Art of Steam Heating” about what can go wrong with a system happened in our building. With your knowledge and after months of working on the problems in units and in the boiler room I’m now just a few more trap rebuilds and a few trap installations away from a well working system. Thank you. I’ve enjoyed the journey. Our HOA is enjoying and will enjoy the benefits, including the lower fuel bills!
    I went through the same experience last winter.  With the help of this forum, I rebuilt all the traps and installed a few main vents and made a few adjustments for a happy old steam heat system.
    Bryant 245-8 2-pipe steam in a 1930s 6-unit 1-story apt building in the NM mountains.  26 radiators heating up 3800sqf.
  • davevarga
    davevarga Member Posts: 46

    Thank you for this great article!

  • RavensNester
    RavensNester Member Posts: 3

    Forgive me for my ignorance but I am a newbie. I believe that the attached picture is of one of two main vents coming off this Burnham IN-5 single piped steam system. Am I correct? If not, where should I look? I know of no other air vents on this system other than the ones on the radiators. Thanks in advance.

    Hoffman4A-Vents.jpg

  • rotaryrkt
    rotaryrkt Member Posts: 1

    I have a Gorton #1 on each end of the mains (one on each side of the basement), but I really think I either need more #1s or a #2. I have the #2 but it's too huge to put it anywhere. Right now, it's a $100 beer coaster. Also, my main vents only really get going when my boiler shuts off, which I think is weird. They will vent slightly until the pipes get hot enough to close the vent and then at boiler shut off, they go crazy venting air.

  • jumper
    jumper Member Posts: 2,385

    This subject has been discussed here for years. My question has also been asked for years.

    "Why can't we eliminate air thoroughly and seal whole system?" Some say resulting vacuum will prevent condensate return. Does this answer make sense?

  • ChrisJ
    ChrisJ Member Posts: 16,316
    https://forum.heatinghelp.com/discussion/comment/1810269#Comment_1810269

    No.

    If I had the time and the money I'd love to build an all copper brazed steam system. Evacuate it and "charge" it with water. I assume it could be topped off with an inert gas like nitrogen to get whatever the required operating temperature is.

    But I'm pretty certain condensate would have no issues returning.

    Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.

  • bburd
    bburd Member Posts: 1,041
    https://forum.heatinghelp.com/discussion/comment/1810247#Comment_1810247

    Yes, those are your main vents.

    —
    Bburd
  • hot1
    hot1 Member Posts: 9

    I service an old YMCA with two pipe steam. The radiators do not have vents. Is that because it's two pipe steam?

  • JUGHNE
    JUGHNE Member Posts: 11,276

    Two pipe rads are vented thru the outlet trap, that air must travel thru the return piping to an air vent.

    Often it is vented out of the vent pipe on a feeder or condensate pump, if used, at the boiler.

    The return piping must not have any water traps (sags) to stop the air before it gets to the vent……also steam coming out of the pump vent means some trap(s) have failed and stuck open.

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