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.

Water loss through steam system air vents

tkrasniqi
tkrasniqi Member Posts: 9
Is there a way to quantify the amount of water being lost through a steam radiator air vent or main vent? 

Comments

  • Big Ed_4
    Big Ed_4 Member Posts: 1,890
    How much is added though the heating season ?
    I have enough experience to know , that I dont know it all
  • tkrasniqi
    tkrasniqi Member Posts: 9
    Hi Ed,

    we lose 50 - 60 gallons of water a day. The boiler is 150 BHP
  • Jamie Hall
    Jamie Hall Member Posts: 18,966
    Supposedly a closed system? Not consumptive use? No steam humidifiers or anything like that?

    If so, that's way too much, although that is a big boiler by the standards around here (roughly 5,000,000 BTUh)...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • KC_Jones
    KC_Jones Member Posts: 5,082
    50 gallons of water would be 85000 gallons of steam or 11,362 cubic feet. If we pick a random say a Hoffman 40 that vents at .087 CFM at 3 ounces of pressure. That vent would have to vent for 131,000 minutes to remove that much steam, and that's after the rad was fully hot, and the vent was failed open.

    Now you have ~5 million BTU boiler, if I do some average efficiency and pick up factor calculation we could surmise say 13,000 EDR (just doing napkin calcs here). With that much EDR and we say an average EDR per rad of 30, we get about 430 radiators, if all of them had a failed vent you'd need to be venting steam from all of them for 300 minutes per day, or 5 straight hours.

    Those are just some very rough calculations, but I think you see what it would take to vent enough steam for that amount of make up water. I just don't see that happening. The vents could be contributing, but don't see that as the primary source.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • tkrasniqi
    tkrasniqi Member Posts: 9
    I appreciate the input. The system has no buried returns or visible leaks. We probably lose some water through flash steam at the condensate tank’s vent. Not sure where the rest of the water is going? 
  • KC_Jones
    KC_Jones Member Posts: 5,082
    Have you verified there isn't a hole in the heat exchanger that is venting steam through the chimney?
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • tkrasniqi
    tkrasniqi Member Posts: 9
    that’s interesting KC. I didn’t think of that. What would be the best way to go about verifying if that is the case? 
  • KC_Jones
    KC_Jones Member Posts: 5,082
    Usually look at the chimney, on a cold day, while the boiler is firing.  If you see a bunch of steam, it’s leaking.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • tkrasniqi
    tkrasniqi Member Posts: 9
    Will do, thanks