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    Natural Gas System sizing and expansion.... (5 Posts)

  • JayKay JayKay @ 5:57 PM
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    Natural Gas System sizing and expansion....

    Howdy,

    I have an Elster Ac-250 meter, looks pretty new, so I gather this means that I have 250K BTU capacity with a 1" coming from the meter.

    This 1" then leads to a larger sized pipe, looks at least 1 1/2" (not sure how to convert circumference to diameter).  This larger pipe leads to the boiler room (maybe 25'-30' from meter)and tees off to two 1/2" pipes, one going to my Lennox Elite G61MPV (75K/110K 2 stage) furnace, the other to two WH hooked up in series (in series for water distribution) (40K BTU each).  The 1/2" going to the WH's first goes to one, tees and connects and continues to the second (i.e. the gas line is hooked up in series also).  The 1 1/2" also continues all the way to my laundry room and terminates in a 1/2" coonection, but is not hooked up to anything at present (maybe another 30' of 1 1/2" line).
     
    I am proposing to add a 54K range (i.e. cooking surface) to the system in the kitchen which is directly above the boiler room, so maybe 10' at most.  From what I can tell this should be fine with the current lines and gas meter that I have.

    My question, however, is whether I can connect the range in series with the 1/2 line that the WH's currently use.  The reason for this is space issues for the installation and the fact that the 1/2 for the WH's is right below and easily accessible.  So tyhis 1/2" line would run the two WH's and the 54K range.

    If I HAD to I can access the 1 1/2" line, but it's all very tight there and I might have to remove some ducting to get in there and do it up right.

    Any and all help is greatly appreciated.

    -JK-
  • JayKay JayKay @ 6:08 PM
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    ONE other additional fact.....

    This post adds to my original post:

    The 1 1/2" line that runs all the way to my laundry room ALSO runs a gas fireplace.  not sure what the BTU is on that, but it's some pretty feeble flames coming out of there.
  • SWEI SWEI @ 8:00 PM
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    In short, no, but...

    can you post a drawing with diameters and lengths?

    Who will be doing the work, and where is the house located?
  • JayKay JayKay @ 8:44 PM
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    No schematics..

    I live outside of Denver, Colorado at 5400 feet elevation.  I would be doing the work myself.  I have checked with the building department and they are fine with that.  I have done plumbing work in the past, also installed my own pool heater (replacement) when I was living in CA.

    I don't have schematics, but imagine a 5 x 10' boiler room in the basement, the furnace occupies 1/3 of the room almost, and then right next to it are two water heaters.  The 1 1/2" has been run along the floor joists and pops down right next to the furnace, the 1/2" pipe going to the furnace has a run of no more than 3 feet, the other 1/2" pipe has a run of about 5 feet to the first water heater and then maybe another four feet to the second water heater.  The cooking range goes into the kitchen  right above the boiler room with  a run of about 8-10 feet from where the 1/2" pipe leading to the water heaters terminates.

    In any case, I was already dubious about my proposal, I was just wondering if it were possible since the furnace draws 110K and my 2 WH's plus range would only draw 134K (40+40+54).  But I also know that distance skews the equations.

    So my next question would be, what if I got rid of one of the water heaters.  I already now leave one off anyhow (we bought the house with this setup, we are only 3 people and I don't see us needing more than the one 50gallon WH).  I had been thinking that if we have company it would be nice to (almost) double our hot water capacity, but this is not a necessity.  Just so the current setup is not a total waste I had been thinking about stripping the insulation from the first water heater in series and just use it as a pre-tank to bring the water temperature up to room temperature before it goes into the second water heater (in CO inlet cold temperature is about 40 degrees).

    So if I remove/incapacitate the first water heater in the series and do not draw any BTU's (so only 40K draw on the line) and then run the 1/2" pipe another 10ft to my kitchen directly above for a total draw of 94K, would this be acceptable.  The total run of 1/2" pipe from the 1 1/2" in this scenario would be about 15'.

    Thanks
    -JK-
  • JayKay JayKay @ 9:01 PM
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    Gas Cooktop is 44K not 54K

    I miscalculated the total BTU for the gas range cooktop, it is 44K, not 54K. 

    I just looked at the specs again and totaled up the various burners, there's one simmer at 5K, two regular burners at 9K, one power burner at 12K and a dual burner at 18K.

    Sorry for the previous misinformation.
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