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To Insulate Or Not

cheezhd
cheezhd Member Posts: 7
edited November 2016 in Strictly Steam
I recently purchased an early 1900s house with my first steam heat system (1-pipe). I have been getting ready to insulate the uninsulated mains with 1 inch fiberglas, but I recently noticed that the boiler appears significantly oversized. The boiler is 128,000 BTU, but my EDR calculation suggests I need only 56,504 BTU. I'm now worried that insulating could lead to significant short cycling. The main is about 80ft of 2 inch iron, and it has a single Gorton #2 main vent (I believe that's all there is currently room for as the vent only has a 1/4 inch tapping). Is the risk of bad short cycling a serious concern that weighs against insulating or shall I go ahead and insulate?

Any advice is most appreciated!

Comments

  • ChrisJ
    ChrisJ Member Posts: 16,317
    Are the steam pipes heating an area you use, or, are they directly under an area you want a warm floor in?

    If they are, I'd leave them exposed.

    If they're in a drafty cold area where you're going to lose a ton of energy I'd probably insulate them.

    What boiler do you have?

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

  • JUGHNE
    JUGHNE Member Posts: 11,279
    It is not that difficult to drill and tap for more venting on the end of the main.
    You could also investigate the feasibility of having a 2 stage gas valve installed on your boiler. It would drop down to perhaps 60% of your existing valve. Would take some set up and different control system components.
  • BobC
    BobC Member Posts: 5,502
    If you can seal up the area the pipes are in and there is living space above I would leave the mains bare but I would insulate the boiler header.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • cheezhd
    cheezhd Member Posts: 7
    Thanks. The boiler is a Smith GSX 206, and it's in an unfinished basement that does get chilly. The pipes are hung a few feet from the ceiling, so I don't think they're doing all that much to heat the floor above.
  • BobC
    BobC Member Posts: 5,502
    My cellar gets into the low 50's now that my piping is insulated. Before the insulation it was about 7 degrees warmer but I don't spend as much time in the cellar these days so I decided to insulate the pipes a few years ago.

    make sure you aren't going to put your water pipes at risk of freezing if that cellar gets too cold.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
    Mark Eatherton
  • ChrisJ
    ChrisJ Member Posts: 16,317
    cheezhd said:

    Thanks. The boiler is a Smith GSX 206, and it's in an unfinished basement that does get chilly. The pipes are hung a few feet from the ceiling, so I don't think they're doing all that much to heat the floor above.

    You'd be amazed.

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

    RomanGK_26986764589
  • Fred
    Fred Member Posts: 8,542
    You can replace that Gorton #2 with a Barnes and Jones BigMouth and get about 50% more venting even with that 1/4" pipe. That 1/4" pipe will vent about 3.4 Cubic feet per minute. The Gorton 2 will vent 2.2 CFM and a BigMouth will vent 3.6 CFM, (all at 3 ounces of pressure). In this case you'll get 3.3 to 3.4 CFM of venting. You will have to change your 1/4X1/2" coupling with a 1/4X3/4" coupling.
    JimIfert

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