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My gas meter just quit screaming at me!

old_washer
old_washer Member Posts: 4


Left - old boiler #39
Middle - new boiler #47 (OEM)
Right - new boiler #51 (after derating for elevation)

This just might help get the NG bill down under $100/mo? :smile:

Comments

  • delta T
    delta T Member Posts: 871
    well......depends on how many there were in the old boiler vs new...

    Looks like it should help though!
  • JUGHNE
    JUGHNE Member Posts: 10,322
    What elevation are you at and how did you calculate the size for that altitude?
  • old_washer
    old_washer Member Posts: 4
    delta T said:

    well......depends on how many there were in the old boiler vs new...

    Old Boiler had 7 orifices
    New boiler has 6.
    JUGHNE said:

    What elevation are you at and how did you calculate the size for that altitude?

    5,500 ft (Suburban Denver)
    The boiler came with #47s.
    Manual states up to 4500 ft should be #49s.
    Derate at 4% per 1,000 ft above 1,000 ft = 16%

    Old boiler clocked at nearly 145K
    New boiler clocks at ~82K with #51 orifices
  • Zman
    Zman Member Posts: 7,435
    What is the boiler rated too? Has a combustion analysis been done?
    Denver natural gas is already derated so you often don't need to go as small as you think. Smaller orifice does not necessarily mean higher efficiency. There is a lot more to it.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Zman
    Zman Member Posts: 7,435
    The derated gas probably makes up for the air density perfectly in your case. If I was guessing, I would think the sea level orifices are pretty close for correct combustion. A combustion analysis will tell you for sure.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • HVACNUT
    HVACNUT Member Posts: 4,871
    > @Zman said:
    >
    > Denver natural gas is already derated so you often don't need to go as small as you think.

    Can you explain that @Zman?
    Derated= less BTU per cu ft?
    Diluted?
  • Zman
    Zman Member Posts: 7,435
    @HVACNUT yes it is intentionally diluted and has less BTU per cubic foot as indicated in the table. It is still billed in therms so that is not an issue.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    delta THVACNUT
  • ratio
    ratio Member Posts: 3,336
    @Erin Holohan Haskell, both of the PDFs above didn't download cleanly, the first one ended up named 'NaturalGasDerate.PDF' & the second is named 'Trane --note the single quotes are part of the filename on my PC. Firefox 70.0.1 (64-bit), Windows 10 Pro Version 10.0.17763 Build 17763.
  • Erin Holohan Haskell
    Erin Holohan Haskell Member, Moderator, Administrator Posts: 1,985
    Thanks for letting us know, @ratio. We've been investigating this issue. If you remove the quotes in the file name, you should be able to open the file. So sorry for the inconvenience.
    President
    HeatingHelp.com
  • Erin Holohan Haskell
    Erin Holohan Haskell Member, Moderator, Administrator Posts: 1,985
    Our team has fixed the file name issue. Thanks for the feedback!
    President
    HeatingHelp.com
    ratio