Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Humidity and Steam Heat

Major7 Member Posts: 44
I live in a neighborhood where lots of homes still have steam heat. One neighbor suggested that the heating system can humidify the house by venting steam into the room. I have never heard of this before. Is this really a thing that can be done?

My home has been in the low teens humidity wise with this recent cold snap. I'd appreciate all your opinions on the matter.


  • Canucker
    Canucker Member Posts: 722
    If you're using steam from your heating system to bring up the humidity levels, your boiler is going to die a quick death from all the fresh water that will have to be replaced.
    The low humidity is from air leaking into your home from outside. Seal the leaks and save some money on your heating bill
    You can have it good, fast or cheap. Pick two
  • ChrisJ
    ChrisJ Member Posts: 15,854
    Your steam system should lose very little water when working right. However it's a heating system not a humidifier and as has already been said trying to use it as one will kill the boiler.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    EBEBRATT-Ed Member Posts: 15,721
    u can however put pans of water on top of your radiators the radiator heat will evaporate the water with no ill effects on your heating systems
  • mikeg2015
    mikeg2015 Member Posts: 1,194
    My Aprilair Steam humidifier boiler can boiler 20 gallons per day to keep it just 20-25%rh on the coldest days. You should see the pile of minerals in the bottom of the plastic tank it has. It blows down about once every hour or so of run time. So water use is another 8-10 gallons or so I’d guess.

    At minimum you’d need a deaeration tank. Even then expect short boiler life.

    The tiny amount of damp air the vents purge is negligible. Maybe a cup a week.
  • Major7
    Major7 Member Posts: 44
    Thanks for the feedback everyone!
  • AMservices
    AMservices Member Posts: 610

    One house I went in had similar devices As the one in the link on their radiators. The homeowner told me they made an improvement

    Google radiator humidifiers
  • mikeg2015
    mikeg2015 Member Posts: 1,194
    Seeing as how my steam humidifier probably puts out over 10 gallon a day to keep up, this would help, but ultimately a drop in the bucket, at least in my house. I'd need one of these in every room and refill them daily...all 15 of them.

    There are steam humidifier with fan powered kits.