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Gas pipe sizing

Gordy
Gordy Member Posts: 9,546
What do you pros do when it comes to gas piping in homes. Do you size the main off the meter for full load potential?



Scenario is as follows: NG



Existing main off of meter to house is 3/4" 60' run gives 85 CFH the home only has a gas water heater with a load of 40 CFH, and a stub for a gas dryer.



New HO is doing away with electric BB heat, and installing a FA 110k btu furnace.

Gas cook top, gas dryer, keeping gas WH, And stub for an outdoor grill



Dryer needs 30 CFH

Wh. 40 CFH

Furnace 110 CFH

Cook top 42 CFH

Hook up for outdoor BBQ. 60 CFH



Total CFH potential 272



Granted the odds of all appliances running at the same time are low, but the chance does exist.



I'm not involved doing the furnace, but this guy wants to tie into the 3/4" existing for his furnace. I told him the gas needs to be up sized from 3/4 to 1 1/4" to the house to get the proper CFH to ALL appliances being installed. Even if nothing else were going to be gas but the furnace, and wh he still needs a bigger gas line.





Where do they come from??

Comments

  • tim smith
    tim smith Member Posts: 2,752
    gas pipe size

     Definately go up to 1.25" pipe.  We size for total load per the International fuel gas code. Also leaving some addl to handle future gas fireplace also I would think.
  • Gordy
    Gordy Member Posts: 9,546
    My thoughts Tim

    Exactly. HO is depending on me to advise plumber.



    Forgot to include meter is 275 CFH.



    Advising 1 1/4" through garage to house with a stub for garage heater potential. Then reduce down to 1" , and t off the 1" to the various appliances.
  • SWEI
    SWEI Member Posts: 7,356
    reduce to 1"

    usually after the first drop in the house.
  • Gordy
    Gordy Member Posts: 9,546
    Thank SWEI

    That was my thoughts.



    Do you do drip legs at vertical transitions in main runs, or only at appliance?b



    From meter main would go through garage wall up 10' across trusses for about 40', and down 10' to go into house



    Should there be drip legs at the 10' vertical points?
  • Paul48
    Paul48 Member Posts: 4,469
    Gas

    No disrespect, if you already know this... http://www.youtube.com/watch?v=mPjEllrv0Bs
  • SWEI
    SWEI Member Posts: 7,356
    sediment traps

    code requires them at all appliances which do not have internal sediment traps.  No mention of vertical runs.



    What the code doesn't say (but some inspectors do) is that locating the gas cock upstream of the trap will allow the trap to be emptied without shutting the whole building down.
  • Gordy
    Gordy Member Posts: 9,546
    None taken Paul

    I do know this, or can figure it out. But I like to check in with you guys.



    Problem is,there are so many hacks out there that have been " doing it that way for 30 years" not even knowing , or caring if they are doing it wrong. Just been getting buy, and/or getting lucky.



    Like this tin knocker who wanted to tap into the existing 3/4" line for his 110k furnace he would not even get 82k in gas, and thats if the water heater does not kick on. He had to leave the site to go,to a no heat call.... Wonder if it was one of his installs with an undersized gas supply line.







    On a side note the owner bought a Jenn Aire downdraft gas cook top. I read the reviews, and some complaints were that it took 20 minutes to boil a pot of water. I immediately thought I,wonder if the gas supply was the right size. Joe blow the homeowner has no clue, and thinks its the cook top that is a sub par product.





    These homeowners higher pros with complete confidence that the job is getting done in a professional manner it goes unnoticed in certain aspects until there is a problem, and they are left holding the bag.
  • icesailor
    icesailor Member Posts: 7,265
    Plumbers:

    What State does this "Plumber" live in and licensed in?
  • icesailor
    icesailor Member Posts: 7,265
    Jenn-Aire's

    I once did a house with a Jenn-Aire cooktop with the vent going down and out. The outlet faced the NW. When it was cold and really blowing, the wind used to flow backwards and into the cooktop. The complaint was that it didn't heat water very fast at times. One night, the woman left a pan on the stove with an inch of water in it. She came down to heat water for her coffee or something and found the water in the pan frozen solid.

    Never underestimate the power of a small air leak to cool down a house.
  • Paul48
    Paul48 Member Posts: 4,469
    Gordy

     There are so many bad contractors out there. The only way a homeowner can protect themselves, is to learn how the job has to be done.We see it here, every day. We've seen a homeowner do everything right, and the contractor pull a switch-a-roo the day of the install.

     The problem exists in every trade, and isn't limited to guys driving around in trucks with the doors falling off.There is no penalty, and the recourse for the homeowner is a joke.
  • Gordy
    Gordy Member Posts: 9,546
    edited December 2012
    Ice

    The plumber is liscensed, and has not done anything wrong yet. he is going to bring the gas pipe up to proper size. I'm just making sure it gets done right after I seen what the liscensed tin knocker wanted to do.



    This is in Illinois
  • Gordy
    Gordy Member Posts: 9,546
    Good to know Ice

    This will be vented out the east side of the house.....or maybe I should vent it in the garage like the previous owner did with the dryer vent??
  • Gordy
    Gordy Member Posts: 9,546
    Relief

    Plumber showed up with national gas code book in hand. We are both on the same page.
  • Gordy
    Gordy Member Posts: 9,546
    Relief

    Plumber showed up with national gas code book in hand. We are both on the same page.
  • Gordy
    Gordy Member Posts: 9,546
    Relief

    Plumber showed up with national gas code book in hand. We are both on the same page.
  • Gordy
    Gordy Member Posts: 9,546
    Relief

    Plumber showed up with national gas code book in hand. We are both on the same page.
  • Gordy
    Gordy Member Posts: 9,546
    Relief

    Plumber showed up with national gas code book in hand. We are both on the same page.
  • Gordy
    Gordy Member Posts: 9,546
    Relief

    Plumber showed up with national gas code book in hand. We are both on the same page.
  • Gordy
    Gordy Member Posts: 9,546
    Relief

    Plumber showed up with national gas code book in hand. We are both on the same page.
  • Gordy
    Gordy Member Posts: 9,546
    Relief

    Plumber showed up with national gas code book in hand. We are both on the same page.
  • Gordy
    Gordy Member Posts: 9,546
    Relief

    Plumber showed up with national gas code book in hand. We are both on the same page.
  • Gordy
    Gordy Member Posts: 9,546
    Relief

    Plumber showed up with national gas code book in hand. We are both on the same page.
  • Gordy
    Gordy Member Posts: 9,546
    Relief

    Plumber showed up with national gas code book in hand. We are both on the same page.
  • Gordy
    Gordy Member Posts: 9,546
    What the

    Heck
  • icesailor
    icesailor Member Posts: 7,265
    What The (Heck)

    "What The (Heck)"

    When you are finished writing, and you click on "Submit Post", click it and wait. Some times you have to wait longer than normal. Wait until the screen changes and the new one comes up with the green bottom that says that post was accepted or words to that effect.

    If you think that it didn't go through and you click again, it will post a second copy of the first post. For every time you click on submit post, it will post another copy.

    Wait before clicking again. That's why you had so many copies of the same message.
  • icesailor
    icesailor Member Posts: 7,265
    edited December 2012
    x

  • bill_105
    bill_105 Member Posts: 429
    I was thinking ...

    Perhaps Gordy is getting an early start on bringing in the New Year. Cheers and HNY:)!!
  • Paul48
    Paul48 Member Posts: 4,469
    He

    showed up a bunch of times. :-)
This discussion has been closed.