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Effecient steam gas boiler installation

jamesfiro Member Posts: 4
I currently have a steam gas 2 pipe boiler installation. The boiler and seperate water heater are in an unheated basement and feed 3 heated levels above. I have 2 questions. When shopping around for a new boiler I get different opinions on how the job shoudl be done. One installer said I need release valves added to the oversized lines to displace the cold air as the hot steam builds to increase effeciency. The other installer said the anti knock valve in place is suffecient and no valves or vents are needed or reccomended. Are release valves needed to be added to my system? My second question is do I need to insulate the lines in the basement. One said that it is best to leave them uninsulated because the basement heats the floor above. Another said to insulate. Thank you for any tips or advice.


  • JStar
    JStar Member Posts: 2,752

    If "release valve" means "air vent" then yes, the more venting on the mains, the better.You want the steam to fill the main as fast as possible.

    I don't know what an "anti knock valve" is.
  • jamesfiro
    jamesfiro Member Posts: 4
    edited November 2011
    yes air vent

    That is correct.I was referring to air vent. I currently have one that I see in the line and was told to add others. Another installer said the one is suffecient.
  • jamesfiro
    jamesfiro Member Posts: 4
    edited November 2011
    double post

    double post
  • BobC
    BobC Member Posts: 5,312
    edited November 2011
    Vent the mains fast

    In a steam system the goal is to vent the steam mains very fast and a lot of systems were built with vents that are just to small. That means your burning extra fuel just to get the air out of the pipes. The size of vent (or multiple vents)is determined by calculating the volume of air in a steam main and this has to be done for each steam main.

    Having adequate sized main venting is important for system efficiency and comfort. It is also important to operate the boiler at low pressure so it might be worth it to pay the extra $$ to have a vaporstat used instead of the usual pressuretrol. Most new pressuretols can't run below 2PSI while a vaporstat can run well down below a pound to save fuel over the long run.

    All near boiler piping and any basement piping you can reach should have a minimum of 1" fiberglass pipe insulation on it and that includes all pipe fittings. You want all that heat upstairs.

    Good luck with your new system.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
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