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What size main vents do I need?

New gas boiler (Burnham IN4), one header that splits to both sides of the house. Each main line is about 30 feet (one is 34 ft the other is 26 ft) of 2" pipe from the boiler to the main vent (so 60 feet total when including both sides).
What size main vents should I have at the end of these lines?
I was planning on buying a Gorton's #1 or #2.
Is there any advantage to having "oversized" main vents (I'm guessing the #2 is just slightly oversized for my unit)?

Comments

  • ChrisJ
    ChrisJ Member Posts: 16,231
    edited September 2015
    I'm running five Gorton #1's on a 29' 2" main.

    If I was you and you have the clearance I'd do a minimum of a single Gorton #2 per main.


    Can you share some pictures of the boiler and it's piping with the forum?
    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
  • fab4ever77
    fab4ever77 Member Posts: 8
    This is for a 1200 sq. ft house, 2 floors
  • KC_Jones
    KC_Jones Member Posts: 5,796
    The rule of thumb around here is 1 Gorton #2 vent for each 20' of 2" pipe. So by that rule Chris's recommendation should be considered a bare minimum in all honesty. You can't really "over vent" your mains, but there is a point of diminishing returns. My mains are much shorter than yours and I am running 3 Gorton #1 on each (I can't fit a #2 or I would have them). For reference 3 #1 vents is close in capacity to a #2.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • ChrisJ
    ChrisJ Member Posts: 16,231
    KC_Jones said:

    The rule of thumb around here is 1 Gorton #2 vent for each 20' of 2" pipe. So by that rule Chris's recommendation should be considered a bare minimum in all honesty. You can't really "over vent" your mains, but there is a point of diminishing returns. My mains are much shorter than yours and I am running 3 Gorton #1 on each (I can't fit a #2 or I would have them). For reference 3 #1 vents is close in capacity to a #2.

    My recommendation was "I'd do a minimum of a single Gorton #2 per main" So yes, it was minimum.
    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
  • KC_Jones
    KC_Jones Member Posts: 5,796
    Sorry Chris I was just restating what you said. Wasn't trying to present it as a disagreement with you.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • fab4ever77
    fab4ever77 Member Posts: 8
    What exactly will faster venting do for me? Should I do a Gorton's 1 and 2 on each side? If I
  • KC_Jones
    KC_Jones Member Posts: 5,796
    Faster venting gets the steam available to the radiators faster. It also allows you to balance the radiators more easily. Think of it this way if you speed the steam to the radiators by 2 minutes then that's 2 minutes of fuel you have saved....on ever cycle. On a cold day 1 cycle per hour, 2 minutes per cycle 48 minutes of gas saved in one day. And then there is the added comfort. On a one pipe system it's all about the venting.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • Fred
    Fred Member Posts: 8,542

    What exactly will faster venting do for me? Should I do a Gorton's 1 and 2 on each side? If I

    If you can get one Gorton #2 and two Gorton #1's on each main, that will give you max venting. Two Gorton #2's will work great also and may be about the same cost as one Gorton #2 and two #1's.

  • SWEI
    SWEI Member Posts: 7,356
    Seems like there's a real need for a bigger vent with a lower profile. @Sailah is this something you guys could make?
  • SWEI
    SWEI Member Posts: 7,356
    When you look at the cost of an antler full of Gorton #2's, a number of possibilities begin to look affordable.

    Belimo's HTCCV is rated for 15 PSI of steam and comes in sizes ranging from a Cv of 0.29 to 28.